1 //===-- AMDGPUISelLowering.cpp - AMDGPU Common DAG lowering functions -----===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 /// \file
10 /// This is the parent TargetLowering class for hardware code gen
11 /// targets.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "AMDGPUISelLowering.h"
16 #include "AMDGPU.h"
17 #include "AMDGPUInstrInfo.h"
18 #include "AMDGPUMachineFunction.h"
19 #include "GCNSubtarget.h"
20 #include "SIMachineFunctionInfo.h"
21 #include "llvm/CodeGen/Analysis.h"
22 #include "llvm/IR/DiagnosticInfo.h"
23 #include "llvm/IR/IntrinsicsAMDGPU.h"
24 #include "llvm/Support/CommandLine.h"
25 #include "llvm/Support/KnownBits.h"
26 #include "llvm/Target/TargetMachine.h"
27 
28 using namespace llvm;
29 
30 #include "AMDGPUGenCallingConv.inc"
31 
32 static cl::opt<bool> AMDGPUBypassSlowDiv(
33   "amdgpu-bypass-slow-div",
34   cl::desc("Skip 64-bit divide for dynamic 32-bit values"),
35   cl::init(true));
36 
37 // Find a larger type to do a load / store of a vector with.
getEquivalentMemType(LLVMContext & Ctx,EVT VT)38 EVT AMDGPUTargetLowering::getEquivalentMemType(LLVMContext &Ctx, EVT VT) {
39   unsigned StoreSize = VT.getStoreSizeInBits();
40   if (StoreSize <= 32)
41     return EVT::getIntegerVT(Ctx, StoreSize);
42 
43   assert(StoreSize % 32 == 0 && "Store size not a multiple of 32");
44   return EVT::getVectorVT(Ctx, MVT::i32, StoreSize / 32);
45 }
46 
numBitsUnsigned(SDValue Op,SelectionDAG & DAG)47 unsigned AMDGPUTargetLowering::numBitsUnsigned(SDValue Op, SelectionDAG &DAG) {
48   EVT VT = Op.getValueType();
49   KnownBits Known = DAG.computeKnownBits(Op);
50   return VT.getSizeInBits() - Known.countMinLeadingZeros();
51 }
52 
numBitsSigned(SDValue Op,SelectionDAG & DAG)53 unsigned AMDGPUTargetLowering::numBitsSigned(SDValue Op, SelectionDAG &DAG) {
54   EVT VT = Op.getValueType();
55 
56   // In order for this to be a signed 24-bit value, bit 23, must
57   // be a sign bit.
58   return VT.getSizeInBits() - DAG.ComputeNumSignBits(Op);
59 }
60 
AMDGPUTargetLowering(const TargetMachine & TM,const AMDGPUSubtarget & STI)61 AMDGPUTargetLowering::AMDGPUTargetLowering(const TargetMachine &TM,
62                                            const AMDGPUSubtarget &STI)
63     : TargetLowering(TM), Subtarget(&STI) {
64   // Lower floating point store/load to integer store/load to reduce the number
65   // of patterns in tablegen.
66   setOperationAction(ISD::LOAD, MVT::f32, Promote);
67   AddPromotedToType(ISD::LOAD, MVT::f32, MVT::i32);
68 
69   setOperationAction(ISD::LOAD, MVT::v2f32, Promote);
70   AddPromotedToType(ISD::LOAD, MVT::v2f32, MVT::v2i32);
71 
72   setOperationAction(ISD::LOAD, MVT::v3f32, Promote);
73   AddPromotedToType(ISD::LOAD, MVT::v3f32, MVT::v3i32);
74 
75   setOperationAction(ISD::LOAD, MVT::v4f32, Promote);
76   AddPromotedToType(ISD::LOAD, MVT::v4f32, MVT::v4i32);
77 
78   setOperationAction(ISD::LOAD, MVT::v5f32, Promote);
79   AddPromotedToType(ISD::LOAD, MVT::v5f32, MVT::v5i32);
80 
81   setOperationAction(ISD::LOAD, MVT::v8f32, Promote);
82   AddPromotedToType(ISD::LOAD, MVT::v8f32, MVT::v8i32);
83 
84   setOperationAction(ISD::LOAD, MVT::v16f32, Promote);
85   AddPromotedToType(ISD::LOAD, MVT::v16f32, MVT::v16i32);
86 
87   setOperationAction(ISD::LOAD, MVT::v32f32, Promote);
88   AddPromotedToType(ISD::LOAD, MVT::v32f32, MVT::v32i32);
89 
90   setOperationAction(ISD::LOAD, MVT::i64, Promote);
91   AddPromotedToType(ISD::LOAD, MVT::i64, MVT::v2i32);
92 
93   setOperationAction(ISD::LOAD, MVT::v2i64, Promote);
94   AddPromotedToType(ISD::LOAD, MVT::v2i64, MVT::v4i32);
95 
96   setOperationAction(ISD::LOAD, MVT::f64, Promote);
97   AddPromotedToType(ISD::LOAD, MVT::f64, MVT::v2i32);
98 
99   setOperationAction(ISD::LOAD, MVT::v2f64, Promote);
100   AddPromotedToType(ISD::LOAD, MVT::v2f64, MVT::v4i32);
101 
102   setOperationAction(ISD::LOAD, MVT::v4i64, Promote);
103   AddPromotedToType(ISD::LOAD, MVT::v4i64, MVT::v8i32);
104 
105   setOperationAction(ISD::LOAD, MVT::v4f64, Promote);
106   AddPromotedToType(ISD::LOAD, MVT::v4f64, MVT::v8i32);
107 
108   setOperationAction(ISD::LOAD, MVT::v8i64, Promote);
109   AddPromotedToType(ISD::LOAD, MVT::v8i64, MVT::v16i32);
110 
111   setOperationAction(ISD::LOAD, MVT::v8f64, Promote);
112   AddPromotedToType(ISD::LOAD, MVT::v8f64, MVT::v16i32);
113 
114   setOperationAction(ISD::LOAD, MVT::v16i64, Promote);
115   AddPromotedToType(ISD::LOAD, MVT::v16i64, MVT::v32i32);
116 
117   setOperationAction(ISD::LOAD, MVT::v16f64, Promote);
118   AddPromotedToType(ISD::LOAD, MVT::v16f64, MVT::v32i32);
119 
120   // There are no 64-bit extloads. These should be done as a 32-bit extload and
121   // an extension to 64-bit.
122   for (MVT VT : MVT::integer_valuetypes()) {
123     setLoadExtAction(ISD::EXTLOAD, MVT::i64, VT, Expand);
124     setLoadExtAction(ISD::SEXTLOAD, MVT::i64, VT, Expand);
125     setLoadExtAction(ISD::ZEXTLOAD, MVT::i64, VT, Expand);
126   }
127 
128   for (MVT VT : MVT::integer_valuetypes()) {
129     if (VT == MVT::i64)
130       continue;
131 
132     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
133     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i8, Legal);
134     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i16, Legal);
135     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i32, Expand);
136 
137     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i1, Promote);
138     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i8, Legal);
139     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i16, Legal);
140     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::i32, Expand);
141 
142     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i1, Promote);
143     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i8, Legal);
144     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i16, Legal);
145     setLoadExtAction(ISD::EXTLOAD, VT, MVT::i32, Expand);
146   }
147 
148   for (MVT VT : MVT::integer_fixedlen_vector_valuetypes()) {
149     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i8, Expand);
150     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i8, Expand);
151     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i8, Expand);
152     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i8, Expand);
153     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i8, Expand);
154     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i8, Expand);
155     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v2i16, Expand);
156     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v2i16, Expand);
157     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v2i16, Expand);
158     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v3i16, Expand);
159     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v3i16, Expand);
160     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v3i16, Expand);
161     setLoadExtAction(ISD::EXTLOAD, VT, MVT::v4i16, Expand);
162     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::v4i16, Expand);
163     setLoadExtAction(ISD::ZEXTLOAD, VT, MVT::v4i16, Expand);
164   }
165 
166   setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
167   setLoadExtAction(ISD::EXTLOAD, MVT::v2f32, MVT::v2f16, Expand);
168   setLoadExtAction(ISD::EXTLOAD, MVT::v3f32, MVT::v3f16, Expand);
169   setLoadExtAction(ISD::EXTLOAD, MVT::v4f32, MVT::v4f16, Expand);
170   setLoadExtAction(ISD::EXTLOAD, MVT::v8f32, MVT::v8f16, Expand);
171   setLoadExtAction(ISD::EXTLOAD, MVT::v16f32, MVT::v16f16, Expand);
172   setLoadExtAction(ISD::EXTLOAD, MVT::v32f32, MVT::v32f16, Expand);
173 
174   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f32, Expand);
175   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f32, Expand);
176   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f32, Expand);
177   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f32, Expand);
178   setLoadExtAction(ISD::EXTLOAD, MVT::v16f64, MVT::v16f32, Expand);
179 
180   setLoadExtAction(ISD::EXTLOAD, MVT::f64, MVT::f16, Expand);
181   setLoadExtAction(ISD::EXTLOAD, MVT::v2f64, MVT::v2f16, Expand);
182   setLoadExtAction(ISD::EXTLOAD, MVT::v4f64, MVT::v4f16, Expand);
183   setLoadExtAction(ISD::EXTLOAD, MVT::v8f64, MVT::v8f16, Expand);
184   setLoadExtAction(ISD::EXTLOAD, MVT::v16f64, MVT::v16f16, Expand);
185 
186   setOperationAction(ISD::STORE, MVT::f32, Promote);
187   AddPromotedToType(ISD::STORE, MVT::f32, MVT::i32);
188 
189   setOperationAction(ISD::STORE, MVT::v2f32, Promote);
190   AddPromotedToType(ISD::STORE, MVT::v2f32, MVT::v2i32);
191 
192   setOperationAction(ISD::STORE, MVT::v3f32, Promote);
193   AddPromotedToType(ISD::STORE, MVT::v3f32, MVT::v3i32);
194 
195   setOperationAction(ISD::STORE, MVT::v4f32, Promote);
196   AddPromotedToType(ISD::STORE, MVT::v4f32, MVT::v4i32);
197 
198   setOperationAction(ISD::STORE, MVT::v5f32, Promote);
199   AddPromotedToType(ISD::STORE, MVT::v5f32, MVT::v5i32);
200 
201   setOperationAction(ISD::STORE, MVT::v8f32, Promote);
202   AddPromotedToType(ISD::STORE, MVT::v8f32, MVT::v8i32);
203 
204   setOperationAction(ISD::STORE, MVT::v16f32, Promote);
205   AddPromotedToType(ISD::STORE, MVT::v16f32, MVT::v16i32);
206 
207   setOperationAction(ISD::STORE, MVT::v32f32, Promote);
208   AddPromotedToType(ISD::STORE, MVT::v32f32, MVT::v32i32);
209 
210   setOperationAction(ISD::STORE, MVT::i64, Promote);
211   AddPromotedToType(ISD::STORE, MVT::i64, MVT::v2i32);
212 
213   setOperationAction(ISD::STORE, MVT::v2i64, Promote);
214   AddPromotedToType(ISD::STORE, MVT::v2i64, MVT::v4i32);
215 
216   setOperationAction(ISD::STORE, MVT::f64, Promote);
217   AddPromotedToType(ISD::STORE, MVT::f64, MVT::v2i32);
218 
219   setOperationAction(ISD::STORE, MVT::v2f64, Promote);
220   AddPromotedToType(ISD::STORE, MVT::v2f64, MVT::v4i32);
221 
222   setOperationAction(ISD::STORE, MVT::v4i64, Promote);
223   AddPromotedToType(ISD::STORE, MVT::v4i64, MVT::v8i32);
224 
225   setOperationAction(ISD::STORE, MVT::v4f64, Promote);
226   AddPromotedToType(ISD::STORE, MVT::v4f64, MVT::v8i32);
227 
228   setOperationAction(ISD::STORE, MVT::v8i64, Promote);
229   AddPromotedToType(ISD::STORE, MVT::v8i64, MVT::v16i32);
230 
231   setOperationAction(ISD::STORE, MVT::v8f64, Promote);
232   AddPromotedToType(ISD::STORE, MVT::v8f64, MVT::v16i32);
233 
234   setOperationAction(ISD::STORE, MVT::v16i64, Promote);
235   AddPromotedToType(ISD::STORE, MVT::v16i64, MVT::v32i32);
236 
237   setOperationAction(ISD::STORE, MVT::v16f64, Promote);
238   AddPromotedToType(ISD::STORE, MVT::v16f64, MVT::v32i32);
239 
240   setTruncStoreAction(MVT::i64, MVT::i1, Expand);
241   setTruncStoreAction(MVT::i64, MVT::i8, Expand);
242   setTruncStoreAction(MVT::i64, MVT::i16, Expand);
243   setTruncStoreAction(MVT::i64, MVT::i32, Expand);
244 
245   setTruncStoreAction(MVT::v2i64, MVT::v2i1, Expand);
246   setTruncStoreAction(MVT::v2i64, MVT::v2i8, Expand);
247   setTruncStoreAction(MVT::v2i64, MVT::v2i16, Expand);
248   setTruncStoreAction(MVT::v2i64, MVT::v2i32, Expand);
249 
250   setTruncStoreAction(MVT::f32, MVT::f16, Expand);
251   setTruncStoreAction(MVT::v2f32, MVT::v2f16, Expand);
252   setTruncStoreAction(MVT::v3f32, MVT::v3f16, Expand);
253   setTruncStoreAction(MVT::v4f32, MVT::v4f16, Expand);
254   setTruncStoreAction(MVT::v8f32, MVT::v8f16, Expand);
255   setTruncStoreAction(MVT::v16f32, MVT::v16f16, Expand);
256   setTruncStoreAction(MVT::v32f32, MVT::v32f16, Expand);
257 
258   setTruncStoreAction(MVT::f64, MVT::f16, Expand);
259   setTruncStoreAction(MVT::f64, MVT::f32, Expand);
260 
261   setTruncStoreAction(MVT::v2f64, MVT::v2f32, Expand);
262   setTruncStoreAction(MVT::v2f64, MVT::v2f16, Expand);
263 
264   setTruncStoreAction(MVT::v4i64, MVT::v4i32, Expand);
265   setTruncStoreAction(MVT::v4i64, MVT::v4i16, Expand);
266   setTruncStoreAction(MVT::v4f64, MVT::v4f32, Expand);
267   setTruncStoreAction(MVT::v4f64, MVT::v4f16, Expand);
268 
269   setTruncStoreAction(MVT::v8f64, MVT::v8f32, Expand);
270   setTruncStoreAction(MVT::v8f64, MVT::v8f16, Expand);
271 
272   setTruncStoreAction(MVT::v16f64, MVT::v16f32, Expand);
273   setTruncStoreAction(MVT::v16f64, MVT::v16f16, Expand);
274   setTruncStoreAction(MVT::v16i64, MVT::v16i16, Expand);
275   setTruncStoreAction(MVT::v16i64, MVT::v16i16, Expand);
276   setTruncStoreAction(MVT::v16i64, MVT::v16i8, Expand);
277   setTruncStoreAction(MVT::v16i64, MVT::v16i8, Expand);
278   setTruncStoreAction(MVT::v16i64, MVT::v16i1, Expand);
279 
280   setOperationAction(ISD::Constant, MVT::i32, Legal);
281   setOperationAction(ISD::Constant, MVT::i64, Legal);
282   setOperationAction(ISD::ConstantFP, MVT::f32, Legal);
283   setOperationAction(ISD::ConstantFP, MVT::f64, Legal);
284 
285   setOperationAction(ISD::BR_JT, MVT::Other, Expand);
286   setOperationAction(ISD::BRIND, MVT::Other, Expand);
287 
288   // This is totally unsupported, just custom lower to produce an error.
289   setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Custom);
290 
291   // Library functions.  These default to Expand, but we have instructions
292   // for them.
293   setOperationAction(ISD::FCEIL,  MVT::f32, Legal);
294   setOperationAction(ISD::FEXP2,  MVT::f32, Legal);
295   setOperationAction(ISD::FPOW,   MVT::f32, Legal);
296   setOperationAction(ISD::FLOG2,  MVT::f32, Legal);
297   setOperationAction(ISD::FABS,   MVT::f32, Legal);
298   setOperationAction(ISD::FFLOOR, MVT::f32, Legal);
299   setOperationAction(ISD::FRINT,  MVT::f32, Legal);
300   setOperationAction(ISD::FTRUNC, MVT::f32, Legal);
301   setOperationAction(ISD::FMINNUM, MVT::f32, Legal);
302   setOperationAction(ISD::FMAXNUM, MVT::f32, Legal);
303 
304   setOperationAction(ISD::FROUND, MVT::f32, Custom);
305   setOperationAction(ISD::FROUND, MVT::f64, Custom);
306 
307   setOperationAction(ISD::FLOG, MVT::f32, Custom);
308   setOperationAction(ISD::FLOG10, MVT::f32, Custom);
309   setOperationAction(ISD::FEXP, MVT::f32, Custom);
310 
311 
312   setOperationAction(ISD::FNEARBYINT, MVT::f32, Custom);
313   setOperationAction(ISD::FNEARBYINT, MVT::f64, Custom);
314 
315   setOperationAction(ISD::FREM, MVT::f16, Custom);
316   setOperationAction(ISD::FREM, MVT::f32, Custom);
317   setOperationAction(ISD::FREM, MVT::f64, Custom);
318 
319   // Expand to fneg + fadd.
320   setOperationAction(ISD::FSUB, MVT::f64, Expand);
321 
322   setOperationAction(ISD::CONCAT_VECTORS, MVT::v3i32, Custom);
323   setOperationAction(ISD::CONCAT_VECTORS, MVT::v3f32, Custom);
324   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4i32, Custom);
325   setOperationAction(ISD::CONCAT_VECTORS, MVT::v4f32, Custom);
326   setOperationAction(ISD::CONCAT_VECTORS, MVT::v5i32, Custom);
327   setOperationAction(ISD::CONCAT_VECTORS, MVT::v5f32, Custom);
328   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8i32, Custom);
329   setOperationAction(ISD::CONCAT_VECTORS, MVT::v8f32, Custom);
330   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2f32, Custom);
331   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2i32, Custom);
332   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v3f32, Custom);
333   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v3i32, Custom);
334   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4f32, Custom);
335   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4i32, Custom);
336   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v5f32, Custom);
337   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v5i32, Custom);
338   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8f32, Custom);
339   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8i32, Custom);
340   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v16f32, Custom);
341   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v16i32, Custom);
342   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v32f32, Custom);
343   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v32i32, Custom);
344   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2f64, Custom);
345   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v2i64, Custom);
346   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4f64, Custom);
347   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v4i64, Custom);
348   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8f64, Custom);
349   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v8i64, Custom);
350   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v16f64, Custom);
351   setOperationAction(ISD::EXTRACT_SUBVECTOR, MVT::v16i64, Custom);
352 
353   setOperationAction(ISD::FP16_TO_FP, MVT::f64, Expand);
354   setOperationAction(ISD::FP_TO_FP16, MVT::f64, Custom);
355   setOperationAction(ISD::FP_TO_FP16, MVT::f32, Custom);
356 
357   const MVT ScalarIntVTs[] = { MVT::i32, MVT::i64 };
358   for (MVT VT : ScalarIntVTs) {
359     // These should use [SU]DIVREM, so set them to expand
360     setOperationAction(ISD::SDIV, VT, Expand);
361     setOperationAction(ISD::UDIV, VT, Expand);
362     setOperationAction(ISD::SREM, VT, Expand);
363     setOperationAction(ISD::UREM, VT, Expand);
364 
365     // GPU does not have divrem function for signed or unsigned.
366     setOperationAction(ISD::SDIVREM, VT, Custom);
367     setOperationAction(ISD::UDIVREM, VT, Custom);
368 
369     // GPU does not have [S|U]MUL_LOHI functions as a single instruction.
370     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
371     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
372 
373     setOperationAction(ISD::BSWAP, VT, Expand);
374     setOperationAction(ISD::CTTZ, VT, Expand);
375     setOperationAction(ISD::CTLZ, VT, Expand);
376 
377     // AMDGPU uses ADDC/SUBC/ADDE/SUBE
378     setOperationAction(ISD::ADDC, VT, Legal);
379     setOperationAction(ISD::SUBC, VT, Legal);
380     setOperationAction(ISD::ADDE, VT, Legal);
381     setOperationAction(ISD::SUBE, VT, Legal);
382   }
383 
384   // The hardware supports 32-bit FSHR, but not FSHL.
385   setOperationAction(ISD::FSHR, MVT::i32, Legal);
386 
387   // The hardware supports 32-bit ROTR, but not ROTL.
388   setOperationAction(ISD::ROTL, MVT::i32, Expand);
389   setOperationAction(ISD::ROTL, MVT::i64, Expand);
390   setOperationAction(ISD::ROTR, MVT::i64, Expand);
391 
392   setOperationAction(ISD::MULHU, MVT::i16, Expand);
393   setOperationAction(ISD::MULHS, MVT::i16, Expand);
394 
395   setOperationAction(ISD::MUL, MVT::i64, Expand);
396   setOperationAction(ISD::MULHU, MVT::i64, Expand);
397   setOperationAction(ISD::MULHS, MVT::i64, Expand);
398   setOperationAction(ISD::UINT_TO_FP, MVT::i64, Custom);
399   setOperationAction(ISD::SINT_TO_FP, MVT::i64, Custom);
400   setOperationAction(ISD::FP_TO_SINT, MVT::i64, Custom);
401   setOperationAction(ISD::FP_TO_UINT, MVT::i64, Custom);
402   setOperationAction(ISD::SELECT_CC, MVT::i64, Expand);
403 
404   setOperationAction(ISD::SMIN, MVT::i32, Legal);
405   setOperationAction(ISD::UMIN, MVT::i32, Legal);
406   setOperationAction(ISD::SMAX, MVT::i32, Legal);
407   setOperationAction(ISD::UMAX, MVT::i32, Legal);
408 
409   setOperationAction(ISD::CTTZ, MVT::i64, Custom);
410   setOperationAction(ISD::CTTZ_ZERO_UNDEF, MVT::i64, Custom);
411   setOperationAction(ISD::CTLZ, MVT::i64, Custom);
412   setOperationAction(ISD::CTLZ_ZERO_UNDEF, MVT::i64, Custom);
413 
414   static const MVT::SimpleValueType VectorIntTypes[] = {
415     MVT::v2i32, MVT::v3i32, MVT::v4i32, MVT::v5i32
416   };
417 
418   for (MVT VT : VectorIntTypes) {
419     // Expand the following operations for the current type by default.
420     setOperationAction(ISD::ADD,  VT, Expand);
421     setOperationAction(ISD::AND,  VT, Expand);
422     setOperationAction(ISD::FP_TO_SINT, VT, Expand);
423     setOperationAction(ISD::FP_TO_UINT, VT, Expand);
424     setOperationAction(ISD::MUL,  VT, Expand);
425     setOperationAction(ISD::MULHU, VT, Expand);
426     setOperationAction(ISD::MULHS, VT, Expand);
427     setOperationAction(ISD::OR,   VT, Expand);
428     setOperationAction(ISD::SHL,  VT, Expand);
429     setOperationAction(ISD::SRA,  VT, Expand);
430     setOperationAction(ISD::SRL,  VT, Expand);
431     setOperationAction(ISD::ROTL, VT, Expand);
432     setOperationAction(ISD::ROTR, VT, Expand);
433     setOperationAction(ISD::SUB,  VT, Expand);
434     setOperationAction(ISD::SINT_TO_FP, VT, Expand);
435     setOperationAction(ISD::UINT_TO_FP, VT, Expand);
436     setOperationAction(ISD::SDIV, VT, Expand);
437     setOperationAction(ISD::UDIV, VT, Expand);
438     setOperationAction(ISD::SREM, VT, Expand);
439     setOperationAction(ISD::UREM, VT, Expand);
440     setOperationAction(ISD::SMUL_LOHI, VT, Expand);
441     setOperationAction(ISD::UMUL_LOHI, VT, Expand);
442     setOperationAction(ISD::SDIVREM, VT, Expand);
443     setOperationAction(ISD::UDIVREM, VT, Expand);
444     setOperationAction(ISD::SELECT, VT, Expand);
445     setOperationAction(ISD::VSELECT, VT, Expand);
446     setOperationAction(ISD::SELECT_CC, VT, Expand);
447     setOperationAction(ISD::XOR,  VT, Expand);
448     setOperationAction(ISD::BSWAP, VT, Expand);
449     setOperationAction(ISD::CTPOP, VT, Expand);
450     setOperationAction(ISD::CTTZ, VT, Expand);
451     setOperationAction(ISD::CTLZ, VT, Expand);
452     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
453     setOperationAction(ISD::SETCC, VT, Expand);
454   }
455 
456   static const MVT::SimpleValueType FloatVectorTypes[] = {
457      MVT::v2f32, MVT::v3f32, MVT::v4f32, MVT::v5f32
458   };
459 
460   for (MVT VT : FloatVectorTypes) {
461     setOperationAction(ISD::FABS, VT, Expand);
462     setOperationAction(ISD::FMINNUM, VT, Expand);
463     setOperationAction(ISD::FMAXNUM, VT, Expand);
464     setOperationAction(ISD::FADD, VT, Expand);
465     setOperationAction(ISD::FCEIL, VT, Expand);
466     setOperationAction(ISD::FCOS, VT, Expand);
467     setOperationAction(ISD::FDIV, VT, Expand);
468     setOperationAction(ISD::FEXP2, VT, Expand);
469     setOperationAction(ISD::FEXP, VT, Expand);
470     setOperationAction(ISD::FLOG2, VT, Expand);
471     setOperationAction(ISD::FREM, VT, Expand);
472     setOperationAction(ISD::FLOG, VT, Expand);
473     setOperationAction(ISD::FLOG10, VT, Expand);
474     setOperationAction(ISD::FPOW, VT, Expand);
475     setOperationAction(ISD::FFLOOR, VT, Expand);
476     setOperationAction(ISD::FTRUNC, VT, Expand);
477     setOperationAction(ISD::FMUL, VT, Expand);
478     setOperationAction(ISD::FMA, VT, Expand);
479     setOperationAction(ISD::FRINT, VT, Expand);
480     setOperationAction(ISD::FNEARBYINT, VT, Expand);
481     setOperationAction(ISD::FSQRT, VT, Expand);
482     setOperationAction(ISD::FSIN, VT, Expand);
483     setOperationAction(ISD::FSUB, VT, Expand);
484     setOperationAction(ISD::FNEG, VT, Expand);
485     setOperationAction(ISD::VSELECT, VT, Expand);
486     setOperationAction(ISD::SELECT_CC, VT, Expand);
487     setOperationAction(ISD::FCOPYSIGN, VT, Expand);
488     setOperationAction(ISD::VECTOR_SHUFFLE, VT, Expand);
489     setOperationAction(ISD::SETCC, VT, Expand);
490     setOperationAction(ISD::FCANONICALIZE, VT, Expand);
491   }
492 
493   // This causes using an unrolled select operation rather than expansion with
494   // bit operations. This is in general better, but the alternative using BFI
495   // instructions may be better if the select sources are SGPRs.
496   setOperationAction(ISD::SELECT, MVT::v2f32, Promote);
497   AddPromotedToType(ISD::SELECT, MVT::v2f32, MVT::v2i32);
498 
499   setOperationAction(ISD::SELECT, MVT::v3f32, Promote);
500   AddPromotedToType(ISD::SELECT, MVT::v3f32, MVT::v3i32);
501 
502   setOperationAction(ISD::SELECT, MVT::v4f32, Promote);
503   AddPromotedToType(ISD::SELECT, MVT::v4f32, MVT::v4i32);
504 
505   setOperationAction(ISD::SELECT, MVT::v5f32, Promote);
506   AddPromotedToType(ISD::SELECT, MVT::v5f32, MVT::v5i32);
507 
508   // There are no libcalls of any kind.
509   for (int I = 0; I < RTLIB::UNKNOWN_LIBCALL; ++I)
510     setLibcallName(static_cast<RTLIB::Libcall>(I), nullptr);
511 
512   setSchedulingPreference(Sched::RegPressure);
513   setJumpIsExpensive(true);
514 
515   // FIXME: This is only partially true. If we have to do vector compares, any
516   // SGPR pair can be a condition register. If we have a uniform condition, we
517   // are better off doing SALU operations, where there is only one SCC. For now,
518   // we don't have a way of knowing during instruction selection if a condition
519   // will be uniform and we always use vector compares. Assume we are using
520   // vector compares until that is fixed.
521   setHasMultipleConditionRegisters(true);
522 
523   setMinCmpXchgSizeInBits(32);
524   setSupportsUnalignedAtomics(false);
525 
526   PredictableSelectIsExpensive = false;
527 
528   // We want to find all load dependencies for long chains of stores to enable
529   // merging into very wide vectors. The problem is with vectors with > 4
530   // elements. MergeConsecutiveStores will attempt to merge these because x8/x16
531   // vectors are a legal type, even though we have to split the loads
532   // usually. When we can more precisely specify load legality per address
533   // space, we should be able to make FindBetterChain/MergeConsecutiveStores
534   // smarter so that they can figure out what to do in 2 iterations without all
535   // N > 4 stores on the same chain.
536   GatherAllAliasesMaxDepth = 16;
537 
538   // memcpy/memmove/memset are expanded in the IR, so we shouldn't need to worry
539   // about these during lowering.
540   MaxStoresPerMemcpy  = 0xffffffff;
541   MaxStoresPerMemmove = 0xffffffff;
542   MaxStoresPerMemset  = 0xffffffff;
543 
544   // The expansion for 64-bit division is enormous.
545   if (AMDGPUBypassSlowDiv)
546     addBypassSlowDiv(64, 32);
547 
548   setTargetDAGCombine(ISD::BITCAST);
549   setTargetDAGCombine(ISD::SHL);
550   setTargetDAGCombine(ISD::SRA);
551   setTargetDAGCombine(ISD::SRL);
552   setTargetDAGCombine(ISD::TRUNCATE);
553   setTargetDAGCombine(ISD::MUL);
554   setTargetDAGCombine(ISD::MULHU);
555   setTargetDAGCombine(ISD::MULHS);
556   setTargetDAGCombine(ISD::SELECT);
557   setTargetDAGCombine(ISD::SELECT_CC);
558   setTargetDAGCombine(ISD::STORE);
559   setTargetDAGCombine(ISD::FADD);
560   setTargetDAGCombine(ISD::FSUB);
561   setTargetDAGCombine(ISD::FNEG);
562   setTargetDAGCombine(ISD::FABS);
563   setTargetDAGCombine(ISD::AssertZext);
564   setTargetDAGCombine(ISD::AssertSext);
565   setTargetDAGCombine(ISD::INTRINSIC_WO_CHAIN);
566 }
567 
mayIgnoreSignedZero(SDValue Op) const568 bool AMDGPUTargetLowering::mayIgnoreSignedZero(SDValue Op) const {
569   if (getTargetMachine().Options.NoSignedZerosFPMath)
570     return true;
571 
572   const auto Flags = Op.getNode()->getFlags();
573   if (Flags.hasNoSignedZeros())
574     return true;
575 
576   return false;
577 }
578 
579 //===----------------------------------------------------------------------===//
580 // Target Information
581 //===----------------------------------------------------------------------===//
582 
583 LLVM_READNONE
fnegFoldsIntoOp(unsigned Opc)584 static bool fnegFoldsIntoOp(unsigned Opc) {
585   switch (Opc) {
586   case ISD::FADD:
587   case ISD::FSUB:
588   case ISD::FMUL:
589   case ISD::FMA:
590   case ISD::FMAD:
591   case ISD::FMINNUM:
592   case ISD::FMAXNUM:
593   case ISD::FMINNUM_IEEE:
594   case ISD::FMAXNUM_IEEE:
595   case ISD::FSIN:
596   case ISD::FTRUNC:
597   case ISD::FRINT:
598   case ISD::FNEARBYINT:
599   case ISD::FCANONICALIZE:
600   case AMDGPUISD::RCP:
601   case AMDGPUISD::RCP_LEGACY:
602   case AMDGPUISD::RCP_IFLAG:
603   case AMDGPUISD::SIN_HW:
604   case AMDGPUISD::FMUL_LEGACY:
605   case AMDGPUISD::FMIN_LEGACY:
606   case AMDGPUISD::FMAX_LEGACY:
607   case AMDGPUISD::FMED3:
608     // TODO: handle llvm.amdgcn.fma.legacy
609     return true;
610   default:
611     return false;
612   }
613 }
614 
615 /// \p returns true if the operation will definitely need to use a 64-bit
616 /// encoding, and thus will use a VOP3 encoding regardless of the source
617 /// modifiers.
618 LLVM_READONLY
opMustUseVOP3Encoding(const SDNode * N,MVT VT)619 static bool opMustUseVOP3Encoding(const SDNode *N, MVT VT) {
620   return N->getNumOperands() > 2 || VT == MVT::f64;
621 }
622 
623 // Most FP instructions support source modifiers, but this could be refined
624 // slightly.
625 LLVM_READONLY
hasSourceMods(const SDNode * N)626 static bool hasSourceMods(const SDNode *N) {
627   if (isa<MemSDNode>(N))
628     return false;
629 
630   switch (N->getOpcode()) {
631   case ISD::CopyToReg:
632   case ISD::SELECT:
633   case ISD::FDIV:
634   case ISD::FREM:
635   case ISD::INLINEASM:
636   case ISD::INLINEASM_BR:
637   case AMDGPUISD::DIV_SCALE:
638   case ISD::INTRINSIC_W_CHAIN:
639 
640   // TODO: Should really be looking at the users of the bitcast. These are
641   // problematic because bitcasts are used to legalize all stores to integer
642   // types.
643   case ISD::BITCAST:
644     return false;
645   case ISD::INTRINSIC_WO_CHAIN: {
646     switch (cast<ConstantSDNode>(N->getOperand(0))->getZExtValue()) {
647     case Intrinsic::amdgcn_interp_p1:
648     case Intrinsic::amdgcn_interp_p2:
649     case Intrinsic::amdgcn_interp_mov:
650     case Intrinsic::amdgcn_interp_p1_f16:
651     case Intrinsic::amdgcn_interp_p2_f16:
652       return false;
653     default:
654       return true;
655     }
656   }
657   default:
658     return true;
659   }
660 }
661 
allUsesHaveSourceMods(const SDNode * N,unsigned CostThreshold)662 bool AMDGPUTargetLowering::allUsesHaveSourceMods(const SDNode *N,
663                                                  unsigned CostThreshold) {
664   // Some users (such as 3-operand FMA/MAD) must use a VOP3 encoding, and thus
665   // it is truly free to use a source modifier in all cases. If there are
666   // multiple users but for each one will necessitate using VOP3, there will be
667   // a code size increase. Try to avoid increasing code size unless we know it
668   // will save on the instruction count.
669   unsigned NumMayIncreaseSize = 0;
670   MVT VT = N->getValueType(0).getScalarType().getSimpleVT();
671 
672   // XXX - Should this limit number of uses to check?
673   for (const SDNode *U : N->uses()) {
674     if (!hasSourceMods(U))
675       return false;
676 
677     if (!opMustUseVOP3Encoding(U, VT)) {
678       if (++NumMayIncreaseSize > CostThreshold)
679         return false;
680     }
681   }
682 
683   return true;
684 }
685 
getTypeForExtReturn(LLVMContext & Context,EVT VT,ISD::NodeType ExtendKind) const686 EVT AMDGPUTargetLowering::getTypeForExtReturn(LLVMContext &Context, EVT VT,
687                                               ISD::NodeType ExtendKind) const {
688   assert(!VT.isVector() && "only scalar expected");
689 
690   // Round to the next multiple of 32-bits.
691   unsigned Size = VT.getSizeInBits();
692   if (Size <= 32)
693     return MVT::i32;
694   return EVT::getIntegerVT(Context, 32 * ((Size + 31) / 32));
695 }
696 
getVectorIdxTy(const DataLayout &) const697 MVT AMDGPUTargetLowering::getVectorIdxTy(const DataLayout &) const {
698   return MVT::i32;
699 }
700 
isSelectSupported(SelectSupportKind SelType) const701 bool AMDGPUTargetLowering::isSelectSupported(SelectSupportKind SelType) const {
702   return true;
703 }
704 
705 // The backend supports 32 and 64 bit floating point immediates.
706 // FIXME: Why are we reporting vectors of FP immediates as legal?
isFPImmLegal(const APFloat & Imm,EVT VT,bool ForCodeSize) const707 bool AMDGPUTargetLowering::isFPImmLegal(const APFloat &Imm, EVT VT,
708                                         bool ForCodeSize) const {
709   EVT ScalarVT = VT.getScalarType();
710   return (ScalarVT == MVT::f32 || ScalarVT == MVT::f64 ||
711          (ScalarVT == MVT::f16 && Subtarget->has16BitInsts()));
712 }
713 
714 // We don't want to shrink f64 / f32 constants.
ShouldShrinkFPConstant(EVT VT) const715 bool AMDGPUTargetLowering::ShouldShrinkFPConstant(EVT VT) const {
716   EVT ScalarVT = VT.getScalarType();
717   return (ScalarVT != MVT::f32 && ScalarVT != MVT::f64);
718 }
719 
shouldReduceLoadWidth(SDNode * N,ISD::LoadExtType ExtTy,EVT NewVT) const720 bool AMDGPUTargetLowering::shouldReduceLoadWidth(SDNode *N,
721                                                  ISD::LoadExtType ExtTy,
722                                                  EVT NewVT) const {
723   // TODO: This may be worth removing. Check regression tests for diffs.
724   if (!TargetLoweringBase::shouldReduceLoadWidth(N, ExtTy, NewVT))
725     return false;
726 
727   unsigned NewSize = NewVT.getStoreSizeInBits();
728 
729   // If we are reducing to a 32-bit load or a smaller multi-dword load,
730   // this is always better.
731   if (NewSize >= 32)
732     return true;
733 
734   EVT OldVT = N->getValueType(0);
735   unsigned OldSize = OldVT.getStoreSizeInBits();
736 
737   MemSDNode *MN = cast<MemSDNode>(N);
738   unsigned AS = MN->getAddressSpace();
739   // Do not shrink an aligned scalar load to sub-dword.
740   // Scalar engine cannot do sub-dword loads.
741   if (OldSize >= 32 && NewSize < 32 && MN->getAlignment() >= 4 &&
742       (AS == AMDGPUAS::CONSTANT_ADDRESS ||
743        AS == AMDGPUAS::CONSTANT_ADDRESS_32BIT ||
744        (isa<LoadSDNode>(N) &&
745         AS == AMDGPUAS::GLOBAL_ADDRESS && MN->isInvariant())) &&
746       AMDGPUInstrInfo::isUniformMMO(MN->getMemOperand()))
747     return false;
748 
749   // Don't produce extloads from sub 32-bit types. SI doesn't have scalar
750   // extloads, so doing one requires using a buffer_load. In cases where we
751   // still couldn't use a scalar load, using the wider load shouldn't really
752   // hurt anything.
753 
754   // If the old size already had to be an extload, there's no harm in continuing
755   // to reduce the width.
756   return (OldSize < 32);
757 }
758 
isLoadBitCastBeneficial(EVT LoadTy,EVT CastTy,const SelectionDAG & DAG,const MachineMemOperand & MMO) const759 bool AMDGPUTargetLowering::isLoadBitCastBeneficial(EVT LoadTy, EVT CastTy,
760                                                    const SelectionDAG &DAG,
761                                                    const MachineMemOperand &MMO) const {
762 
763   assert(LoadTy.getSizeInBits() == CastTy.getSizeInBits());
764 
765   if (LoadTy.getScalarType() == MVT::i32)
766     return false;
767 
768   unsigned LScalarSize = LoadTy.getScalarSizeInBits();
769   unsigned CastScalarSize = CastTy.getScalarSizeInBits();
770 
771   if ((LScalarSize >= CastScalarSize) && (CastScalarSize < 32))
772     return false;
773 
774   bool Fast = false;
775   return allowsMemoryAccessForAlignment(*DAG.getContext(), DAG.getDataLayout(),
776                                         CastTy, MMO, &Fast) &&
777          Fast;
778 }
779 
780 // SI+ has instructions for cttz / ctlz for 32-bit values. This is probably also
781 // profitable with the expansion for 64-bit since it's generally good to
782 // speculate things.
783 // FIXME: These should really have the size as a parameter.
isCheapToSpeculateCttz() const784 bool AMDGPUTargetLowering::isCheapToSpeculateCttz() const {
785   return true;
786 }
787 
isCheapToSpeculateCtlz() const788 bool AMDGPUTargetLowering::isCheapToSpeculateCtlz() const {
789   return true;
790 }
791 
isSDNodeAlwaysUniform(const SDNode * N) const792 bool AMDGPUTargetLowering::isSDNodeAlwaysUniform(const SDNode *N) const {
793   switch (N->getOpcode()) {
794   case ISD::EntryToken:
795   case ISD::TokenFactor:
796     return true;
797   case ISD::INTRINSIC_WO_CHAIN: {
798     unsigned IntrID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
799     switch (IntrID) {
800     case Intrinsic::amdgcn_readfirstlane:
801     case Intrinsic::amdgcn_readlane:
802       return true;
803     }
804     return false;
805   }
806   case ISD::LOAD:
807     if (cast<LoadSDNode>(N)->getMemOperand()->getAddrSpace() ==
808         AMDGPUAS::CONSTANT_ADDRESS_32BIT)
809       return true;
810     return false;
811   }
812   return false;
813 }
814 
getNegatedExpression(SDValue Op,SelectionDAG & DAG,bool LegalOperations,bool ForCodeSize,NegatibleCost & Cost,unsigned Depth) const815 SDValue AMDGPUTargetLowering::getNegatedExpression(
816     SDValue Op, SelectionDAG &DAG, bool LegalOperations, bool ForCodeSize,
817     NegatibleCost &Cost, unsigned Depth) const {
818 
819   switch (Op.getOpcode()) {
820   case ISD::FMA:
821   case ISD::FMAD: {
822     // Negating a fma is not free if it has users without source mods.
823     if (!allUsesHaveSourceMods(Op.getNode()))
824       return SDValue();
825     break;
826   }
827   default:
828     break;
829   }
830 
831   return TargetLowering::getNegatedExpression(Op, DAG, LegalOperations,
832                                               ForCodeSize, Cost, Depth);
833 }
834 
835 //===---------------------------------------------------------------------===//
836 // Target Properties
837 //===---------------------------------------------------------------------===//
838 
isFAbsFree(EVT VT) const839 bool AMDGPUTargetLowering::isFAbsFree(EVT VT) const {
840   assert(VT.isFloatingPoint());
841 
842   // Packed operations do not have a fabs modifier.
843   return VT == MVT::f32 || VT == MVT::f64 ||
844          (Subtarget->has16BitInsts() && VT == MVT::f16);
845 }
846 
isFNegFree(EVT VT) const847 bool AMDGPUTargetLowering::isFNegFree(EVT VT) const {
848   assert(VT.isFloatingPoint());
849   return VT == MVT::f32 || VT == MVT::f64 ||
850          (Subtarget->has16BitInsts() && VT == MVT::f16) ||
851          (Subtarget->hasVOP3PInsts() && VT == MVT::v2f16);
852 }
853 
storeOfVectorConstantIsCheap(EVT MemVT,unsigned NumElem,unsigned AS) const854 bool AMDGPUTargetLowering:: storeOfVectorConstantIsCheap(EVT MemVT,
855                                                          unsigned NumElem,
856                                                          unsigned AS) const {
857   return true;
858 }
859 
aggressivelyPreferBuildVectorSources(EVT VecVT) const860 bool AMDGPUTargetLowering::aggressivelyPreferBuildVectorSources(EVT VecVT) const {
861   // There are few operations which truly have vector input operands. Any vector
862   // operation is going to involve operations on each component, and a
863   // build_vector will be a copy per element, so it always makes sense to use a
864   // build_vector input in place of the extracted element to avoid a copy into a
865   // super register.
866   //
867   // We should probably only do this if all users are extracts only, but this
868   // should be the common case.
869   return true;
870 }
871 
isTruncateFree(EVT Source,EVT Dest) const872 bool AMDGPUTargetLowering::isTruncateFree(EVT Source, EVT Dest) const {
873   // Truncate is just accessing a subregister.
874 
875   unsigned SrcSize = Source.getSizeInBits();
876   unsigned DestSize = Dest.getSizeInBits();
877 
878   return DestSize < SrcSize && DestSize % 32 == 0 ;
879 }
880 
isTruncateFree(Type * Source,Type * Dest) const881 bool AMDGPUTargetLowering::isTruncateFree(Type *Source, Type *Dest) const {
882   // Truncate is just accessing a subregister.
883 
884   unsigned SrcSize = Source->getScalarSizeInBits();
885   unsigned DestSize = Dest->getScalarSizeInBits();
886 
887   if (DestSize== 16 && Subtarget->has16BitInsts())
888     return SrcSize >= 32;
889 
890   return DestSize < SrcSize && DestSize % 32 == 0;
891 }
892 
isZExtFree(Type * Src,Type * Dest) const893 bool AMDGPUTargetLowering::isZExtFree(Type *Src, Type *Dest) const {
894   unsigned SrcSize = Src->getScalarSizeInBits();
895   unsigned DestSize = Dest->getScalarSizeInBits();
896 
897   if (SrcSize == 16 && Subtarget->has16BitInsts())
898     return DestSize >= 32;
899 
900   return SrcSize == 32 && DestSize == 64;
901 }
902 
isZExtFree(EVT Src,EVT Dest) const903 bool AMDGPUTargetLowering::isZExtFree(EVT Src, EVT Dest) const {
904   // Any register load of a 64-bit value really requires 2 32-bit moves. For all
905   // practical purposes, the extra mov 0 to load a 64-bit is free.  As used,
906   // this will enable reducing 64-bit operations the 32-bit, which is always
907   // good.
908 
909   if (Src == MVT::i16)
910     return Dest == MVT::i32 ||Dest == MVT::i64 ;
911 
912   return Src == MVT::i32 && Dest == MVT::i64;
913 }
914 
isZExtFree(SDValue Val,EVT VT2) const915 bool AMDGPUTargetLowering::isZExtFree(SDValue Val, EVT VT2) const {
916   return isZExtFree(Val.getValueType(), VT2);
917 }
918 
isNarrowingProfitable(EVT SrcVT,EVT DestVT) const919 bool AMDGPUTargetLowering::isNarrowingProfitable(EVT SrcVT, EVT DestVT) const {
920   // There aren't really 64-bit registers, but pairs of 32-bit ones and only a
921   // limited number of native 64-bit operations. Shrinking an operation to fit
922   // in a single 32-bit register should always be helpful. As currently used,
923   // this is much less general than the name suggests, and is only used in
924   // places trying to reduce the sizes of loads. Shrinking loads to < 32-bits is
925   // not profitable, and may actually be harmful.
926   return SrcVT.getSizeInBits() > 32 && DestVT.getSizeInBits() == 32;
927 }
928 
929 //===---------------------------------------------------------------------===//
930 // TargetLowering Callbacks
931 //===---------------------------------------------------------------------===//
932 
CCAssignFnForCall(CallingConv::ID CC,bool IsVarArg)933 CCAssignFn *AMDGPUCallLowering::CCAssignFnForCall(CallingConv::ID CC,
934                                                   bool IsVarArg) {
935   switch (CC) {
936   case CallingConv::AMDGPU_VS:
937   case CallingConv::AMDGPU_GS:
938   case CallingConv::AMDGPU_PS:
939   case CallingConv::AMDGPU_CS:
940   case CallingConv::AMDGPU_HS:
941   case CallingConv::AMDGPU_ES:
942   case CallingConv::AMDGPU_LS:
943     return CC_AMDGPU;
944   case CallingConv::C:
945   case CallingConv::Fast:
946   case CallingConv::Cold:
947     return CC_AMDGPU_Func;
948   case CallingConv::AMDGPU_Gfx:
949     return CC_SI_Gfx;
950   case CallingConv::AMDGPU_KERNEL:
951   case CallingConv::SPIR_KERNEL:
952   default:
953     report_fatal_error("Unsupported calling convention for call");
954   }
955 }
956 
CCAssignFnForReturn(CallingConv::ID CC,bool IsVarArg)957 CCAssignFn *AMDGPUCallLowering::CCAssignFnForReturn(CallingConv::ID CC,
958                                                     bool IsVarArg) {
959   switch (CC) {
960   case CallingConv::AMDGPU_KERNEL:
961   case CallingConv::SPIR_KERNEL:
962     llvm_unreachable("kernels should not be handled here");
963   case CallingConv::AMDGPU_VS:
964   case CallingConv::AMDGPU_GS:
965   case CallingConv::AMDGPU_PS:
966   case CallingConv::AMDGPU_CS:
967   case CallingConv::AMDGPU_HS:
968   case CallingConv::AMDGPU_ES:
969   case CallingConv::AMDGPU_LS:
970     return RetCC_SI_Shader;
971   case CallingConv::AMDGPU_Gfx:
972     return RetCC_SI_Gfx;
973   case CallingConv::C:
974   case CallingConv::Fast:
975   case CallingConv::Cold:
976     return RetCC_AMDGPU_Func;
977   default:
978     report_fatal_error("Unsupported calling convention.");
979   }
980 }
981 
982 /// The SelectionDAGBuilder will automatically promote function arguments
983 /// with illegal types.  However, this does not work for the AMDGPU targets
984 /// since the function arguments are stored in memory as these illegal types.
985 /// In order to handle this properly we need to get the original types sizes
986 /// from the LLVM IR Function and fixup the ISD:InputArg values before
987 /// passing them to AnalyzeFormalArguments()
988 
989 /// When the SelectionDAGBuilder computes the Ins, it takes care of splitting
990 /// input values across multiple registers.  Each item in the Ins array
991 /// represents a single value that will be stored in registers.  Ins[x].VT is
992 /// the value type of the value that will be stored in the register, so
993 /// whatever SDNode we lower the argument to needs to be this type.
994 ///
995 /// In order to correctly lower the arguments we need to know the size of each
996 /// argument.  Since Ins[x].VT gives us the size of the register that will
997 /// hold the value, we need to look at Ins[x].ArgVT to see the 'real' type
998 /// for the orignal function argument so that we can deduce the correct memory
999 /// type to use for Ins[x].  In most cases the correct memory type will be
1000 /// Ins[x].ArgVT.  However, this will not always be the case.  If, for example,
1001 /// we have a kernel argument of type v8i8, this argument will be split into
1002 /// 8 parts and each part will be represented by its own item in the Ins array.
1003 /// For each part the Ins[x].ArgVT will be the v8i8, which is the full type of
1004 /// the argument before it was split.  From this, we deduce that the memory type
1005 /// for each individual part is i8.  We pass the memory type as LocVT to the
1006 /// calling convention analysis function and the register type (Ins[x].VT) as
1007 /// the ValVT.
analyzeFormalArgumentsCompute(CCState & State,const SmallVectorImpl<ISD::InputArg> & Ins) const1008 void AMDGPUTargetLowering::analyzeFormalArgumentsCompute(
1009   CCState &State,
1010   const SmallVectorImpl<ISD::InputArg> &Ins) const {
1011   const MachineFunction &MF = State.getMachineFunction();
1012   const Function &Fn = MF.getFunction();
1013   LLVMContext &Ctx = Fn.getParent()->getContext();
1014   const AMDGPUSubtarget &ST = AMDGPUSubtarget::get(MF);
1015   const unsigned ExplicitOffset = ST.getExplicitKernelArgOffset(Fn);
1016   CallingConv::ID CC = Fn.getCallingConv();
1017 
1018   Align MaxAlign = Align(1);
1019   uint64_t ExplicitArgOffset = 0;
1020   const DataLayout &DL = Fn.getParent()->getDataLayout();
1021 
1022   unsigned InIndex = 0;
1023 
1024   for (const Argument &Arg : Fn.args()) {
1025     const bool IsByRef = Arg.hasByRefAttr();
1026     Type *BaseArgTy = Arg.getType();
1027     Type *MemArgTy = IsByRef ? Arg.getParamByRefType() : BaseArgTy;
1028     MaybeAlign Alignment = IsByRef ? Arg.getParamAlign() : None;
1029     if (!Alignment)
1030       Alignment = DL.getABITypeAlign(MemArgTy);
1031     MaxAlign = max(Alignment, MaxAlign);
1032     uint64_t AllocSize = DL.getTypeAllocSize(MemArgTy);
1033 
1034     uint64_t ArgOffset = alignTo(ExplicitArgOffset, Alignment) + ExplicitOffset;
1035     ExplicitArgOffset = alignTo(ExplicitArgOffset, Alignment) + AllocSize;
1036 
1037     // We're basically throwing away everything passed into us and starting over
1038     // to get accurate in-memory offsets. The "PartOffset" is completely useless
1039     // to us as computed in Ins.
1040     //
1041     // We also need to figure out what type legalization is trying to do to get
1042     // the correct memory offsets.
1043 
1044     SmallVector<EVT, 16> ValueVTs;
1045     SmallVector<uint64_t, 16> Offsets;
1046     ComputeValueVTs(*this, DL, BaseArgTy, ValueVTs, &Offsets, ArgOffset);
1047 
1048     for (unsigned Value = 0, NumValues = ValueVTs.size();
1049          Value != NumValues; ++Value) {
1050       uint64_t BasePartOffset = Offsets[Value];
1051 
1052       EVT ArgVT = ValueVTs[Value];
1053       EVT MemVT = ArgVT;
1054       MVT RegisterVT = getRegisterTypeForCallingConv(Ctx, CC, ArgVT);
1055       unsigned NumRegs = getNumRegistersForCallingConv(Ctx, CC, ArgVT);
1056 
1057       if (NumRegs == 1) {
1058         // This argument is not split, so the IR type is the memory type.
1059         if (ArgVT.isExtended()) {
1060           // We have an extended type, like i24, so we should just use the
1061           // register type.
1062           MemVT = RegisterVT;
1063         } else {
1064           MemVT = ArgVT;
1065         }
1066       } else if (ArgVT.isVector() && RegisterVT.isVector() &&
1067                  ArgVT.getScalarType() == RegisterVT.getScalarType()) {
1068         assert(ArgVT.getVectorNumElements() > RegisterVT.getVectorNumElements());
1069         // We have a vector value which has been split into a vector with
1070         // the same scalar type, but fewer elements.  This should handle
1071         // all the floating-point vector types.
1072         MemVT = RegisterVT;
1073       } else if (ArgVT.isVector() &&
1074                  ArgVT.getVectorNumElements() == NumRegs) {
1075         // This arg has been split so that each element is stored in a separate
1076         // register.
1077         MemVT = ArgVT.getScalarType();
1078       } else if (ArgVT.isExtended()) {
1079         // We have an extended type, like i65.
1080         MemVT = RegisterVT;
1081       } else {
1082         unsigned MemoryBits = ArgVT.getStoreSizeInBits() / NumRegs;
1083         assert(ArgVT.getStoreSizeInBits() % NumRegs == 0);
1084         if (RegisterVT.isInteger()) {
1085           MemVT = EVT::getIntegerVT(State.getContext(), MemoryBits);
1086         } else if (RegisterVT.isVector()) {
1087           assert(!RegisterVT.getScalarType().isFloatingPoint());
1088           unsigned NumElements = RegisterVT.getVectorNumElements();
1089           assert(MemoryBits % NumElements == 0);
1090           // This vector type has been split into another vector type with
1091           // a different elements size.
1092           EVT ScalarVT = EVT::getIntegerVT(State.getContext(),
1093                                            MemoryBits / NumElements);
1094           MemVT = EVT::getVectorVT(State.getContext(), ScalarVT, NumElements);
1095         } else {
1096           llvm_unreachable("cannot deduce memory type.");
1097         }
1098       }
1099 
1100       // Convert one element vectors to scalar.
1101       if (MemVT.isVector() && MemVT.getVectorNumElements() == 1)
1102         MemVT = MemVT.getScalarType();
1103 
1104       // Round up vec3/vec5 argument.
1105       if (MemVT.isVector() && !MemVT.isPow2VectorType()) {
1106         assert(MemVT.getVectorNumElements() == 3 ||
1107                MemVT.getVectorNumElements() == 5);
1108         MemVT = MemVT.getPow2VectorType(State.getContext());
1109       } else if (!MemVT.isSimple() && !MemVT.isVector()) {
1110         MemVT = MemVT.getRoundIntegerType(State.getContext());
1111       }
1112 
1113       unsigned PartOffset = 0;
1114       for (unsigned i = 0; i != NumRegs; ++i) {
1115         State.addLoc(CCValAssign::getCustomMem(InIndex++, RegisterVT,
1116                                                BasePartOffset + PartOffset,
1117                                                MemVT.getSimpleVT(),
1118                                                CCValAssign::Full));
1119         PartOffset += MemVT.getStoreSize();
1120       }
1121     }
1122   }
1123 }
1124 
LowerReturn(SDValue Chain,CallingConv::ID CallConv,bool isVarArg,const SmallVectorImpl<ISD::OutputArg> & Outs,const SmallVectorImpl<SDValue> & OutVals,const SDLoc & DL,SelectionDAG & DAG) const1125 SDValue AMDGPUTargetLowering::LowerReturn(
1126   SDValue Chain, CallingConv::ID CallConv,
1127   bool isVarArg,
1128   const SmallVectorImpl<ISD::OutputArg> &Outs,
1129   const SmallVectorImpl<SDValue> &OutVals,
1130   const SDLoc &DL, SelectionDAG &DAG) const {
1131   // FIXME: Fails for r600 tests
1132   //assert(!isVarArg && Outs.empty() && OutVals.empty() &&
1133   // "wave terminate should not have return values");
1134   return DAG.getNode(AMDGPUISD::ENDPGM, DL, MVT::Other, Chain);
1135 }
1136 
1137 //===---------------------------------------------------------------------===//
1138 // Target specific lowering
1139 //===---------------------------------------------------------------------===//
1140 
1141 /// Selects the correct CCAssignFn for a given CallingConvention value.
CCAssignFnForCall(CallingConv::ID CC,bool IsVarArg)1142 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForCall(CallingConv::ID CC,
1143                                                     bool IsVarArg) {
1144   return AMDGPUCallLowering::CCAssignFnForCall(CC, IsVarArg);
1145 }
1146 
CCAssignFnForReturn(CallingConv::ID CC,bool IsVarArg)1147 CCAssignFn *AMDGPUTargetLowering::CCAssignFnForReturn(CallingConv::ID CC,
1148                                                       bool IsVarArg) {
1149   return AMDGPUCallLowering::CCAssignFnForReturn(CC, IsVarArg);
1150 }
1151 
addTokenForArgument(SDValue Chain,SelectionDAG & DAG,MachineFrameInfo & MFI,int ClobberedFI) const1152 SDValue AMDGPUTargetLowering::addTokenForArgument(SDValue Chain,
1153                                                   SelectionDAG &DAG,
1154                                                   MachineFrameInfo &MFI,
1155                                                   int ClobberedFI) const {
1156   SmallVector<SDValue, 8> ArgChains;
1157   int64_t FirstByte = MFI.getObjectOffset(ClobberedFI);
1158   int64_t LastByte = FirstByte + MFI.getObjectSize(ClobberedFI) - 1;
1159 
1160   // Include the original chain at the beginning of the list. When this is
1161   // used by target LowerCall hooks, this helps legalize find the
1162   // CALLSEQ_BEGIN node.
1163   ArgChains.push_back(Chain);
1164 
1165   // Add a chain value for each stack argument corresponding
1166   for (SDNode::use_iterator U = DAG.getEntryNode().getNode()->use_begin(),
1167                             UE = DAG.getEntryNode().getNode()->use_end();
1168        U != UE; ++U) {
1169     if (LoadSDNode *L = dyn_cast<LoadSDNode>(*U)) {
1170       if (FrameIndexSDNode *FI = dyn_cast<FrameIndexSDNode>(L->getBasePtr())) {
1171         if (FI->getIndex() < 0) {
1172           int64_t InFirstByte = MFI.getObjectOffset(FI->getIndex());
1173           int64_t InLastByte = InFirstByte;
1174           InLastByte += MFI.getObjectSize(FI->getIndex()) - 1;
1175 
1176           if ((InFirstByte <= FirstByte && FirstByte <= InLastByte) ||
1177               (FirstByte <= InFirstByte && InFirstByte <= LastByte))
1178             ArgChains.push_back(SDValue(L, 1));
1179         }
1180       }
1181     }
1182   }
1183 
1184   // Build a tokenfactor for all the chains.
1185   return DAG.getNode(ISD::TokenFactor, SDLoc(Chain), MVT::Other, ArgChains);
1186 }
1187 
lowerUnhandledCall(CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals,StringRef Reason) const1188 SDValue AMDGPUTargetLowering::lowerUnhandledCall(CallLoweringInfo &CLI,
1189                                                  SmallVectorImpl<SDValue> &InVals,
1190                                                  StringRef Reason) const {
1191   SDValue Callee = CLI.Callee;
1192   SelectionDAG &DAG = CLI.DAG;
1193 
1194   const Function &Fn = DAG.getMachineFunction().getFunction();
1195 
1196   StringRef FuncName("<unknown>");
1197 
1198   if (const ExternalSymbolSDNode *G = dyn_cast<ExternalSymbolSDNode>(Callee))
1199     FuncName = G->getSymbol();
1200   else if (const GlobalAddressSDNode *G = dyn_cast<GlobalAddressSDNode>(Callee))
1201     FuncName = G->getGlobal()->getName();
1202 
1203   DiagnosticInfoUnsupported NoCalls(
1204     Fn, Reason + FuncName, CLI.DL.getDebugLoc());
1205   DAG.getContext()->diagnose(NoCalls);
1206 
1207   if (!CLI.IsTailCall) {
1208     for (unsigned I = 0, E = CLI.Ins.size(); I != E; ++I)
1209       InVals.push_back(DAG.getUNDEF(CLI.Ins[I].VT));
1210   }
1211 
1212   return DAG.getEntryNode();
1213 }
1214 
LowerCall(CallLoweringInfo & CLI,SmallVectorImpl<SDValue> & InVals) const1215 SDValue AMDGPUTargetLowering::LowerCall(CallLoweringInfo &CLI,
1216                                         SmallVectorImpl<SDValue> &InVals) const {
1217   return lowerUnhandledCall(CLI, InVals, "unsupported call to function ");
1218 }
1219 
LowerDYNAMIC_STACKALLOC(SDValue Op,SelectionDAG & DAG) const1220 SDValue AMDGPUTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
1221                                                       SelectionDAG &DAG) const {
1222   const Function &Fn = DAG.getMachineFunction().getFunction();
1223 
1224   DiagnosticInfoUnsupported NoDynamicAlloca(Fn, "unsupported dynamic alloca",
1225                                             SDLoc(Op).getDebugLoc());
1226   DAG.getContext()->diagnose(NoDynamicAlloca);
1227   auto Ops = {DAG.getConstant(0, SDLoc(), Op.getValueType()), Op.getOperand(0)};
1228   return DAG.getMergeValues(Ops, SDLoc());
1229 }
1230 
LowerOperation(SDValue Op,SelectionDAG & DAG) const1231 SDValue AMDGPUTargetLowering::LowerOperation(SDValue Op,
1232                                              SelectionDAG &DAG) const {
1233   switch (Op.getOpcode()) {
1234   default:
1235     Op->print(errs(), &DAG);
1236     llvm_unreachable("Custom lowering code for this "
1237                      "instruction is not implemented yet!");
1238     break;
1239   case ISD::SIGN_EXTEND_INREG: return LowerSIGN_EXTEND_INREG(Op, DAG);
1240   case ISD::CONCAT_VECTORS: return LowerCONCAT_VECTORS(Op, DAG);
1241   case ISD::EXTRACT_SUBVECTOR: return LowerEXTRACT_SUBVECTOR(Op, DAG);
1242   case ISD::UDIVREM: return LowerUDIVREM(Op, DAG);
1243   case ISD::SDIVREM: return LowerSDIVREM(Op, DAG);
1244   case ISD::FREM: return LowerFREM(Op, DAG);
1245   case ISD::FCEIL: return LowerFCEIL(Op, DAG);
1246   case ISD::FTRUNC: return LowerFTRUNC(Op, DAG);
1247   case ISD::FRINT: return LowerFRINT(Op, DAG);
1248   case ISD::FNEARBYINT: return LowerFNEARBYINT(Op, DAG);
1249   case ISD::FROUND: return LowerFROUND(Op, DAG);
1250   case ISD::FFLOOR: return LowerFFLOOR(Op, DAG);
1251   case ISD::FLOG:
1252     return LowerFLOG(Op, DAG, numbers::ln2f);
1253   case ISD::FLOG10:
1254     return LowerFLOG(Op, DAG, numbers::ln2f / numbers::ln10f);
1255   case ISD::FEXP:
1256     return lowerFEXP(Op, DAG);
1257   case ISD::SINT_TO_FP: return LowerSINT_TO_FP(Op, DAG);
1258   case ISD::UINT_TO_FP: return LowerUINT_TO_FP(Op, DAG);
1259   case ISD::FP_TO_FP16: return LowerFP_TO_FP16(Op, DAG);
1260   case ISD::FP_TO_SINT:
1261   case ISD::FP_TO_UINT:
1262     return LowerFP_TO_INT(Op, DAG);
1263   case ISD::CTTZ:
1264   case ISD::CTTZ_ZERO_UNDEF:
1265   case ISD::CTLZ:
1266   case ISD::CTLZ_ZERO_UNDEF:
1267     return LowerCTLZ_CTTZ(Op, DAG);
1268   case ISD::DYNAMIC_STACKALLOC: return LowerDYNAMIC_STACKALLOC(Op, DAG);
1269   }
1270   return Op;
1271 }
1272 
ReplaceNodeResults(SDNode * N,SmallVectorImpl<SDValue> & Results,SelectionDAG & DAG) const1273 void AMDGPUTargetLowering::ReplaceNodeResults(SDNode *N,
1274                                               SmallVectorImpl<SDValue> &Results,
1275                                               SelectionDAG &DAG) const {
1276   switch (N->getOpcode()) {
1277   case ISD::SIGN_EXTEND_INREG:
1278     // Different parts of legalization seem to interpret which type of
1279     // sign_extend_inreg is the one to check for custom lowering. The extended
1280     // from type is what really matters, but some places check for custom
1281     // lowering of the result type. This results in trying to use
1282     // ReplaceNodeResults to sext_in_reg to an illegal type, so we'll just do
1283     // nothing here and let the illegal result integer be handled normally.
1284     return;
1285   default:
1286     return;
1287   }
1288 }
1289 
hasDefinedInitializer(const GlobalValue * GV)1290 bool AMDGPUTargetLowering::hasDefinedInitializer(const GlobalValue *GV) {
1291   const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV);
1292   if (!GVar || !GVar->hasInitializer())
1293     return false;
1294 
1295   return !isa<UndefValue>(GVar->getInitializer());
1296 }
1297 
LowerGlobalAddress(AMDGPUMachineFunction * MFI,SDValue Op,SelectionDAG & DAG) const1298 SDValue AMDGPUTargetLowering::LowerGlobalAddress(AMDGPUMachineFunction* MFI,
1299                                                  SDValue Op,
1300                                                  SelectionDAG &DAG) const {
1301 
1302   const DataLayout &DL = DAG.getDataLayout();
1303   GlobalAddressSDNode *G = cast<GlobalAddressSDNode>(Op);
1304   const GlobalValue *GV = G->getGlobal();
1305 
1306   if (G->getAddressSpace() == AMDGPUAS::LOCAL_ADDRESS ||
1307       G->getAddressSpace() == AMDGPUAS::REGION_ADDRESS) {
1308     if (!MFI->isModuleEntryFunction() &&
1309         !GV->getName().equals("llvm.amdgcn.module.lds")) {
1310       SDLoc DL(Op);
1311       const Function &Fn = DAG.getMachineFunction().getFunction();
1312       DiagnosticInfoUnsupported BadLDSDecl(
1313         Fn, "local memory global used by non-kernel function",
1314         DL.getDebugLoc(), DS_Warning);
1315       DAG.getContext()->diagnose(BadLDSDecl);
1316 
1317       // We currently don't have a way to correctly allocate LDS objects that
1318       // aren't directly associated with a kernel. We do force inlining of
1319       // functions that use local objects. However, if these dead functions are
1320       // not eliminated, we don't want a compile time error. Just emit a warning
1321       // and a trap, since there should be no callable path here.
1322       SDValue Trap = DAG.getNode(ISD::TRAP, DL, MVT::Other, DAG.getEntryNode());
1323       SDValue OutputChain = DAG.getNode(ISD::TokenFactor, DL, MVT::Other,
1324                                         Trap, DAG.getRoot());
1325       DAG.setRoot(OutputChain);
1326       return DAG.getUNDEF(Op.getValueType());
1327     }
1328 
1329     // XXX: What does the value of G->getOffset() mean?
1330     assert(G->getOffset() == 0 &&
1331          "Do not know what to do with an non-zero offset");
1332 
1333     // TODO: We could emit code to handle the initialization somewhere.
1334     if (!hasDefinedInitializer(GV)) {
1335       unsigned Offset = MFI->allocateLDSGlobal(DL, *cast<GlobalVariable>(GV));
1336       return DAG.getConstant(Offset, SDLoc(Op), Op.getValueType());
1337     }
1338   }
1339 
1340   const Function &Fn = DAG.getMachineFunction().getFunction();
1341   DiagnosticInfoUnsupported BadInit(
1342       Fn, "unsupported initializer for address space", SDLoc(Op).getDebugLoc());
1343   DAG.getContext()->diagnose(BadInit);
1344   return SDValue();
1345 }
1346 
LowerCONCAT_VECTORS(SDValue Op,SelectionDAG & DAG) const1347 SDValue AMDGPUTargetLowering::LowerCONCAT_VECTORS(SDValue Op,
1348                                                   SelectionDAG &DAG) const {
1349   SmallVector<SDValue, 8> Args;
1350 
1351   EVT VT = Op.getValueType();
1352   if (VT == MVT::v4i16 || VT == MVT::v4f16) {
1353     SDLoc SL(Op);
1354     SDValue Lo = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(0));
1355     SDValue Hi = DAG.getNode(ISD::BITCAST, SL, MVT::i32, Op.getOperand(1));
1356 
1357     SDValue BV = DAG.getBuildVector(MVT::v2i32, SL, { Lo, Hi });
1358     return DAG.getNode(ISD::BITCAST, SL, VT, BV);
1359   }
1360 
1361   for (const SDUse &U : Op->ops())
1362     DAG.ExtractVectorElements(U.get(), Args);
1363 
1364   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1365 }
1366 
LowerEXTRACT_SUBVECTOR(SDValue Op,SelectionDAG & DAG) const1367 SDValue AMDGPUTargetLowering::LowerEXTRACT_SUBVECTOR(SDValue Op,
1368                                                      SelectionDAG &DAG) const {
1369 
1370   SmallVector<SDValue, 8> Args;
1371   unsigned Start = cast<ConstantSDNode>(Op.getOperand(1))->getZExtValue();
1372   EVT VT = Op.getValueType();
1373   DAG.ExtractVectorElements(Op.getOperand(0), Args, Start,
1374                             VT.getVectorNumElements());
1375 
1376   return DAG.getBuildVector(Op.getValueType(), SDLoc(Op), Args);
1377 }
1378 
1379 /// Generate Min/Max node
combineFMinMaxLegacy(const SDLoc & DL,EVT VT,SDValue LHS,SDValue RHS,SDValue True,SDValue False,SDValue CC,DAGCombinerInfo & DCI) const1380 SDValue AMDGPUTargetLowering::combineFMinMaxLegacy(const SDLoc &DL, EVT VT,
1381                                                    SDValue LHS, SDValue RHS,
1382                                                    SDValue True, SDValue False,
1383                                                    SDValue CC,
1384                                                    DAGCombinerInfo &DCI) const {
1385   if (!(LHS == True && RHS == False) && !(LHS == False && RHS == True))
1386     return SDValue();
1387 
1388   SelectionDAG &DAG = DCI.DAG;
1389   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(CC)->get();
1390   switch (CCOpcode) {
1391   case ISD::SETOEQ:
1392   case ISD::SETONE:
1393   case ISD::SETUNE:
1394   case ISD::SETNE:
1395   case ISD::SETUEQ:
1396   case ISD::SETEQ:
1397   case ISD::SETFALSE:
1398   case ISD::SETFALSE2:
1399   case ISD::SETTRUE:
1400   case ISD::SETTRUE2:
1401   case ISD::SETUO:
1402   case ISD::SETO:
1403     break;
1404   case ISD::SETULE:
1405   case ISD::SETULT: {
1406     if (LHS == True)
1407       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1408     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1409   }
1410   case ISD::SETOLE:
1411   case ISD::SETOLT:
1412   case ISD::SETLE:
1413   case ISD::SETLT: {
1414     // Ordered. Assume ordered for undefined.
1415 
1416     // Only do this after legalization to avoid interfering with other combines
1417     // which might occur.
1418     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1419         !DCI.isCalledByLegalizer())
1420       return SDValue();
1421 
1422     // We need to permute the operands to get the correct NaN behavior. The
1423     // selected operand is the second one based on the failing compare with NaN,
1424     // so permute it based on the compare type the hardware uses.
1425     if (LHS == True)
1426       return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1427     return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1428   }
1429   case ISD::SETUGE:
1430   case ISD::SETUGT: {
1431     if (LHS == True)
1432       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, RHS, LHS);
1433     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, LHS, RHS);
1434   }
1435   case ISD::SETGT:
1436   case ISD::SETGE:
1437   case ISD::SETOGE:
1438   case ISD::SETOGT: {
1439     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG &&
1440         !DCI.isCalledByLegalizer())
1441       return SDValue();
1442 
1443     if (LHS == True)
1444       return DAG.getNode(AMDGPUISD::FMAX_LEGACY, DL, VT, LHS, RHS);
1445     return DAG.getNode(AMDGPUISD::FMIN_LEGACY, DL, VT, RHS, LHS);
1446   }
1447   case ISD::SETCC_INVALID:
1448     llvm_unreachable("Invalid setcc condcode!");
1449   }
1450   return SDValue();
1451 }
1452 
1453 std::pair<SDValue, SDValue>
split64BitValue(SDValue Op,SelectionDAG & DAG) const1454 AMDGPUTargetLowering::split64BitValue(SDValue Op, SelectionDAG &DAG) const {
1455   SDLoc SL(Op);
1456 
1457   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1458 
1459   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1460   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1461 
1462   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1463   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1464 
1465   return std::make_pair(Lo, Hi);
1466 }
1467 
getLoHalf64(SDValue Op,SelectionDAG & DAG) const1468 SDValue AMDGPUTargetLowering::getLoHalf64(SDValue Op, SelectionDAG &DAG) const {
1469   SDLoc SL(Op);
1470 
1471   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1472   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
1473   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
1474 }
1475 
getHiHalf64(SDValue Op,SelectionDAG & DAG) const1476 SDValue AMDGPUTargetLowering::getHiHalf64(SDValue Op, SelectionDAG &DAG) const {
1477   SDLoc SL(Op);
1478 
1479   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Op);
1480   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
1481   return DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
1482 }
1483 
1484 // Split a vector type into two parts. The first part is a power of two vector.
1485 // The second part is whatever is left over, and is a scalar if it would
1486 // otherwise be a 1-vector.
1487 std::pair<EVT, EVT>
getSplitDestVTs(const EVT & VT,SelectionDAG & DAG) const1488 AMDGPUTargetLowering::getSplitDestVTs(const EVT &VT, SelectionDAG &DAG) const {
1489   EVT LoVT, HiVT;
1490   EVT EltVT = VT.getVectorElementType();
1491   unsigned NumElts = VT.getVectorNumElements();
1492   unsigned LoNumElts = PowerOf2Ceil((NumElts + 1) / 2);
1493   LoVT = EVT::getVectorVT(*DAG.getContext(), EltVT, LoNumElts);
1494   HiVT = NumElts - LoNumElts == 1
1495              ? EltVT
1496              : EVT::getVectorVT(*DAG.getContext(), EltVT, NumElts - LoNumElts);
1497   return std::make_pair(LoVT, HiVT);
1498 }
1499 
1500 // Split a vector value into two parts of types LoVT and HiVT. HiVT could be
1501 // scalar.
1502 std::pair<SDValue, SDValue>
splitVector(const SDValue & N,const SDLoc & DL,const EVT & LoVT,const EVT & HiVT,SelectionDAG & DAG) const1503 AMDGPUTargetLowering::splitVector(const SDValue &N, const SDLoc &DL,
1504                                   const EVT &LoVT, const EVT &HiVT,
1505                                   SelectionDAG &DAG) const {
1506   assert(LoVT.getVectorNumElements() +
1507                  (HiVT.isVector() ? HiVT.getVectorNumElements() : 1) <=
1508              N.getValueType().getVectorNumElements() &&
1509          "More vector elements requested than available!");
1510   SDValue Lo = DAG.getNode(ISD::EXTRACT_SUBVECTOR, DL, LoVT, N,
1511                            DAG.getVectorIdxConstant(0, DL));
1512   SDValue Hi = DAG.getNode(
1513       HiVT.isVector() ? ISD::EXTRACT_SUBVECTOR : ISD::EXTRACT_VECTOR_ELT, DL,
1514       HiVT, N, DAG.getVectorIdxConstant(LoVT.getVectorNumElements(), DL));
1515   return std::make_pair(Lo, Hi);
1516 }
1517 
SplitVectorLoad(const SDValue Op,SelectionDAG & DAG) const1518 SDValue AMDGPUTargetLowering::SplitVectorLoad(const SDValue Op,
1519                                               SelectionDAG &DAG) const {
1520   LoadSDNode *Load = cast<LoadSDNode>(Op);
1521   EVT VT = Op.getValueType();
1522   SDLoc SL(Op);
1523 
1524 
1525   // If this is a 2 element vector, we really want to scalarize and not create
1526   // weird 1 element vectors.
1527   if (VT.getVectorNumElements() == 2) {
1528     SDValue Ops[2];
1529     std::tie(Ops[0], Ops[1]) = scalarizeVectorLoad(Load, DAG);
1530     return DAG.getMergeValues(Ops, SL);
1531   }
1532 
1533   SDValue BasePtr = Load->getBasePtr();
1534   EVT MemVT = Load->getMemoryVT();
1535 
1536   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1537 
1538   EVT LoVT, HiVT;
1539   EVT LoMemVT, HiMemVT;
1540   SDValue Lo, Hi;
1541 
1542   std::tie(LoVT, HiVT) = getSplitDestVTs(VT, DAG);
1543   std::tie(LoMemVT, HiMemVT) = getSplitDestVTs(MemVT, DAG);
1544   std::tie(Lo, Hi) = splitVector(Op, SL, LoVT, HiVT, DAG);
1545 
1546   unsigned Size = LoMemVT.getStoreSize();
1547   unsigned BaseAlign = Load->getAlignment();
1548   unsigned HiAlign = MinAlign(BaseAlign, Size);
1549 
1550   SDValue LoLoad = DAG.getExtLoad(Load->getExtensionType(), SL, LoVT,
1551                                   Load->getChain(), BasePtr, SrcValue, LoMemVT,
1552                                   BaseAlign, Load->getMemOperand()->getFlags());
1553   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, TypeSize::Fixed(Size));
1554   SDValue HiLoad =
1555       DAG.getExtLoad(Load->getExtensionType(), SL, HiVT, Load->getChain(),
1556                      HiPtr, SrcValue.getWithOffset(LoMemVT.getStoreSize()),
1557                      HiMemVT, HiAlign, Load->getMemOperand()->getFlags());
1558 
1559   SDValue Join;
1560   if (LoVT == HiVT) {
1561     // This is the case that the vector is power of two so was evenly split.
1562     Join = DAG.getNode(ISD::CONCAT_VECTORS, SL, VT, LoLoad, HiLoad);
1563   } else {
1564     Join = DAG.getNode(ISD::INSERT_SUBVECTOR, SL, VT, DAG.getUNDEF(VT), LoLoad,
1565                        DAG.getVectorIdxConstant(0, SL));
1566     Join = DAG.getNode(
1567         HiVT.isVector() ? ISD::INSERT_SUBVECTOR : ISD::INSERT_VECTOR_ELT, SL,
1568         VT, Join, HiLoad,
1569         DAG.getVectorIdxConstant(LoVT.getVectorNumElements(), SL));
1570   }
1571 
1572   SDValue Ops[] = {Join, DAG.getNode(ISD::TokenFactor, SL, MVT::Other,
1573                                      LoLoad.getValue(1), HiLoad.getValue(1))};
1574 
1575   return DAG.getMergeValues(Ops, SL);
1576 }
1577 
WidenOrSplitVectorLoad(SDValue Op,SelectionDAG & DAG) const1578 SDValue AMDGPUTargetLowering::WidenOrSplitVectorLoad(SDValue Op,
1579                                                      SelectionDAG &DAG) const {
1580   LoadSDNode *Load = cast<LoadSDNode>(Op);
1581   EVT VT = Op.getValueType();
1582   SDValue BasePtr = Load->getBasePtr();
1583   EVT MemVT = Load->getMemoryVT();
1584   SDLoc SL(Op);
1585   const MachinePointerInfo &SrcValue = Load->getMemOperand()->getPointerInfo();
1586   unsigned BaseAlign = Load->getAlignment();
1587   unsigned NumElements = MemVT.getVectorNumElements();
1588 
1589   // Widen from vec3 to vec4 when the load is at least 8-byte aligned
1590   // or 16-byte fully dereferenceable. Otherwise, split the vector load.
1591   if (NumElements != 3 ||
1592       (BaseAlign < 8 &&
1593        !SrcValue.isDereferenceable(16, *DAG.getContext(), DAG.getDataLayout())))
1594     return SplitVectorLoad(Op, DAG);
1595 
1596   assert(NumElements == 3);
1597 
1598   EVT WideVT =
1599       EVT::getVectorVT(*DAG.getContext(), VT.getVectorElementType(), 4);
1600   EVT WideMemVT =
1601       EVT::getVectorVT(*DAG.getContext(), MemVT.getVectorElementType(), 4);
1602   SDValue WideLoad = DAG.getExtLoad(
1603       Load->getExtensionType(), SL, WideVT, Load->getChain(), BasePtr, SrcValue,
1604       WideMemVT, BaseAlign, Load->getMemOperand()->getFlags());
1605   return DAG.getMergeValues(
1606       {DAG.getNode(ISD::EXTRACT_SUBVECTOR, SL, VT, WideLoad,
1607                    DAG.getVectorIdxConstant(0, SL)),
1608        WideLoad.getValue(1)},
1609       SL);
1610 }
1611 
SplitVectorStore(SDValue Op,SelectionDAG & DAG) const1612 SDValue AMDGPUTargetLowering::SplitVectorStore(SDValue Op,
1613                                                SelectionDAG &DAG) const {
1614   StoreSDNode *Store = cast<StoreSDNode>(Op);
1615   SDValue Val = Store->getValue();
1616   EVT VT = Val.getValueType();
1617 
1618   // If this is a 2 element vector, we really want to scalarize and not create
1619   // weird 1 element vectors.
1620   if (VT.getVectorNumElements() == 2)
1621     return scalarizeVectorStore(Store, DAG);
1622 
1623   EVT MemVT = Store->getMemoryVT();
1624   SDValue Chain = Store->getChain();
1625   SDValue BasePtr = Store->getBasePtr();
1626   SDLoc SL(Op);
1627 
1628   EVT LoVT, HiVT;
1629   EVT LoMemVT, HiMemVT;
1630   SDValue Lo, Hi;
1631 
1632   std::tie(LoVT, HiVT) = getSplitDestVTs(VT, DAG);
1633   std::tie(LoMemVT, HiMemVT) = getSplitDestVTs(MemVT, DAG);
1634   std::tie(Lo, Hi) = splitVector(Val, SL, LoVT, HiVT, DAG);
1635 
1636   SDValue HiPtr = DAG.getObjectPtrOffset(SL, BasePtr, LoMemVT.getStoreSize());
1637 
1638   const MachinePointerInfo &SrcValue = Store->getMemOperand()->getPointerInfo();
1639   unsigned BaseAlign = Store->getAlignment();
1640   unsigned Size = LoMemVT.getStoreSize();
1641   unsigned HiAlign = MinAlign(BaseAlign, Size);
1642 
1643   SDValue LoStore =
1644       DAG.getTruncStore(Chain, SL, Lo, BasePtr, SrcValue, LoMemVT, BaseAlign,
1645                         Store->getMemOperand()->getFlags());
1646   SDValue HiStore =
1647       DAG.getTruncStore(Chain, SL, Hi, HiPtr, SrcValue.getWithOffset(Size),
1648                         HiMemVT, HiAlign, Store->getMemOperand()->getFlags());
1649 
1650   return DAG.getNode(ISD::TokenFactor, SL, MVT::Other, LoStore, HiStore);
1651 }
1652 
1653 // This is a shortcut for integer division because we have fast i32<->f32
1654 // conversions, and fast f32 reciprocal instructions. The fractional part of a
1655 // float is enough to accurately represent up to a 24-bit signed integer.
LowerDIVREM24(SDValue Op,SelectionDAG & DAG,bool Sign) const1656 SDValue AMDGPUTargetLowering::LowerDIVREM24(SDValue Op, SelectionDAG &DAG,
1657                                             bool Sign) const {
1658   SDLoc DL(Op);
1659   EVT VT = Op.getValueType();
1660   SDValue LHS = Op.getOperand(0);
1661   SDValue RHS = Op.getOperand(1);
1662   MVT IntVT = MVT::i32;
1663   MVT FltVT = MVT::f32;
1664 
1665   unsigned LHSSignBits = DAG.ComputeNumSignBits(LHS);
1666   if (LHSSignBits < 9)
1667     return SDValue();
1668 
1669   unsigned RHSSignBits = DAG.ComputeNumSignBits(RHS);
1670   if (RHSSignBits < 9)
1671     return SDValue();
1672 
1673   unsigned BitSize = VT.getSizeInBits();
1674   unsigned SignBits = std::min(LHSSignBits, RHSSignBits);
1675   unsigned DivBits = BitSize - SignBits;
1676   if (Sign)
1677     ++DivBits;
1678 
1679   ISD::NodeType ToFp = Sign ? ISD::SINT_TO_FP : ISD::UINT_TO_FP;
1680   ISD::NodeType ToInt = Sign ? ISD::FP_TO_SINT : ISD::FP_TO_UINT;
1681 
1682   SDValue jq = DAG.getConstant(1, DL, IntVT);
1683 
1684   if (Sign) {
1685     // char|short jq = ia ^ ib;
1686     jq = DAG.getNode(ISD::XOR, DL, VT, LHS, RHS);
1687 
1688     // jq = jq >> (bitsize - 2)
1689     jq = DAG.getNode(ISD::SRA, DL, VT, jq,
1690                      DAG.getConstant(BitSize - 2, DL, VT));
1691 
1692     // jq = jq | 0x1
1693     jq = DAG.getNode(ISD::OR, DL, VT, jq, DAG.getConstant(1, DL, VT));
1694   }
1695 
1696   // int ia = (int)LHS;
1697   SDValue ia = LHS;
1698 
1699   // int ib, (int)RHS;
1700   SDValue ib = RHS;
1701 
1702   // float fa = (float)ia;
1703   SDValue fa = DAG.getNode(ToFp, DL, FltVT, ia);
1704 
1705   // float fb = (float)ib;
1706   SDValue fb = DAG.getNode(ToFp, DL, FltVT, ib);
1707 
1708   SDValue fq = DAG.getNode(ISD::FMUL, DL, FltVT,
1709                            fa, DAG.getNode(AMDGPUISD::RCP, DL, FltVT, fb));
1710 
1711   // fq = trunc(fq);
1712   fq = DAG.getNode(ISD::FTRUNC, DL, FltVT, fq);
1713 
1714   // float fqneg = -fq;
1715   SDValue fqneg = DAG.getNode(ISD::FNEG, DL, FltVT, fq);
1716 
1717   MachineFunction &MF = DAG.getMachineFunction();
1718   const AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
1719 
1720   // float fr = mad(fqneg, fb, fa);
1721   unsigned OpCode = !Subtarget->hasMadMacF32Insts() ?
1722                     (unsigned)ISD::FMA :
1723                     !MFI->getMode().allFP32Denormals() ?
1724                     (unsigned)ISD::FMAD :
1725                     (unsigned)AMDGPUISD::FMAD_FTZ;
1726   SDValue fr = DAG.getNode(OpCode, DL, FltVT, fqneg, fb, fa);
1727 
1728   // int iq = (int)fq;
1729   SDValue iq = DAG.getNode(ToInt, DL, IntVT, fq);
1730 
1731   // fr = fabs(fr);
1732   fr = DAG.getNode(ISD::FABS, DL, FltVT, fr);
1733 
1734   // fb = fabs(fb);
1735   fb = DAG.getNode(ISD::FABS, DL, FltVT, fb);
1736 
1737   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
1738 
1739   // int cv = fr >= fb;
1740   SDValue cv = DAG.getSetCC(DL, SetCCVT, fr, fb, ISD::SETOGE);
1741 
1742   // jq = (cv ? jq : 0);
1743   jq = DAG.getNode(ISD::SELECT, DL, VT, cv, jq, DAG.getConstant(0, DL, VT));
1744 
1745   // dst = iq + jq;
1746   SDValue Div = DAG.getNode(ISD::ADD, DL, VT, iq, jq);
1747 
1748   // Rem needs compensation, it's easier to recompute it
1749   SDValue Rem = DAG.getNode(ISD::MUL, DL, VT, Div, RHS);
1750   Rem = DAG.getNode(ISD::SUB, DL, VT, LHS, Rem);
1751 
1752   // Truncate to number of bits this divide really is.
1753   if (Sign) {
1754     SDValue InRegSize
1755       = DAG.getValueType(EVT::getIntegerVT(*DAG.getContext(), DivBits));
1756     Div = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Div, InRegSize);
1757     Rem = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, VT, Rem, InRegSize);
1758   } else {
1759     SDValue TruncMask = DAG.getConstant((UINT64_C(1) << DivBits) - 1, DL, VT);
1760     Div = DAG.getNode(ISD::AND, DL, VT, Div, TruncMask);
1761     Rem = DAG.getNode(ISD::AND, DL, VT, Rem, TruncMask);
1762   }
1763 
1764   return DAG.getMergeValues({ Div, Rem }, DL);
1765 }
1766 
LowerUDIVREM64(SDValue Op,SelectionDAG & DAG,SmallVectorImpl<SDValue> & Results) const1767 void AMDGPUTargetLowering::LowerUDIVREM64(SDValue Op,
1768                                       SelectionDAG &DAG,
1769                                       SmallVectorImpl<SDValue> &Results) const {
1770   SDLoc DL(Op);
1771   EVT VT = Op.getValueType();
1772 
1773   assert(VT == MVT::i64 && "LowerUDIVREM64 expects an i64");
1774 
1775   EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
1776 
1777   SDValue One = DAG.getConstant(1, DL, HalfVT);
1778   SDValue Zero = DAG.getConstant(0, DL, HalfVT);
1779 
1780   //HiLo split
1781   SDValue LHS = Op.getOperand(0);
1782   SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
1783   SDValue LHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, One);
1784 
1785   SDValue RHS = Op.getOperand(1);
1786   SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
1787   SDValue RHS_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, One);
1788 
1789   if (DAG.MaskedValueIsZero(RHS, APInt::getHighBitsSet(64, 32)) &&
1790       DAG.MaskedValueIsZero(LHS, APInt::getHighBitsSet(64, 32))) {
1791 
1792     SDValue Res = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
1793                               LHS_Lo, RHS_Lo);
1794 
1795     SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(0), Zero});
1796     SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {Res.getValue(1), Zero});
1797 
1798     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV));
1799     Results.push_back(DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM));
1800     return;
1801   }
1802 
1803   if (isTypeLegal(MVT::i64)) {
1804     MachineFunction &MF = DAG.getMachineFunction();
1805     const SIMachineFunctionInfo *MFI = MF.getInfo<SIMachineFunctionInfo>();
1806 
1807     // Compute denominator reciprocal.
1808     unsigned FMAD = !Subtarget->hasMadMacF32Insts() ?
1809                     (unsigned)ISD::FMA :
1810                     !MFI->getMode().allFP32Denormals() ?
1811                     (unsigned)ISD::FMAD :
1812                     (unsigned)AMDGPUISD::FMAD_FTZ;
1813 
1814     SDValue Cvt_Lo = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Lo);
1815     SDValue Cvt_Hi = DAG.getNode(ISD::UINT_TO_FP, DL, MVT::f32, RHS_Hi);
1816     SDValue Mad1 = DAG.getNode(FMAD, DL, MVT::f32, Cvt_Hi,
1817       DAG.getConstantFP(APInt(32, 0x4f800000).bitsToFloat(), DL, MVT::f32),
1818       Cvt_Lo);
1819     SDValue Rcp = DAG.getNode(AMDGPUISD::RCP, DL, MVT::f32, Mad1);
1820     SDValue Mul1 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Rcp,
1821       DAG.getConstantFP(APInt(32, 0x5f7ffffc).bitsToFloat(), DL, MVT::f32));
1822     SDValue Mul2 = DAG.getNode(ISD::FMUL, DL, MVT::f32, Mul1,
1823       DAG.getConstantFP(APInt(32, 0x2f800000).bitsToFloat(), DL, MVT::f32));
1824     SDValue Trunc = DAG.getNode(ISD::FTRUNC, DL, MVT::f32, Mul2);
1825     SDValue Mad2 = DAG.getNode(FMAD, DL, MVT::f32, Trunc,
1826       DAG.getConstantFP(APInt(32, 0xcf800000).bitsToFloat(), DL, MVT::f32),
1827       Mul1);
1828     SDValue Rcp_Lo = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Mad2);
1829     SDValue Rcp_Hi = DAG.getNode(ISD::FP_TO_UINT, DL, HalfVT, Trunc);
1830     SDValue Rcp64 = DAG.getBitcast(VT,
1831                         DAG.getBuildVector(MVT::v2i32, DL, {Rcp_Lo, Rcp_Hi}));
1832 
1833     SDValue Zero64 = DAG.getConstant(0, DL, VT);
1834     SDValue One64  = DAG.getConstant(1, DL, VT);
1835     SDValue Zero1 = DAG.getConstant(0, DL, MVT::i1);
1836     SDVTList HalfCarryVT = DAG.getVTList(HalfVT, MVT::i1);
1837 
1838     SDValue Neg_RHS = DAG.getNode(ISD::SUB, DL, VT, Zero64, RHS);
1839     SDValue Mullo1 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Rcp64);
1840     SDValue Mulhi1 = DAG.getNode(ISD::MULHU, DL, VT, Rcp64, Mullo1);
1841     SDValue Mulhi1_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1842                                     Zero);
1843     SDValue Mulhi1_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi1,
1844                                     One);
1845 
1846     SDValue Add1_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Lo,
1847                                   Mulhi1_Lo, Zero1);
1848     SDValue Add1_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Rcp_Hi,
1849                                   Mulhi1_Hi, Add1_Lo.getValue(1));
1850     SDValue Add1_HiNc = DAG.getNode(ISD::ADD, DL, HalfVT, Rcp_Hi, Mulhi1_Hi);
1851     SDValue Add1 = DAG.getBitcast(VT,
1852                         DAG.getBuildVector(MVT::v2i32, DL, {Add1_Lo, Add1_Hi}));
1853 
1854     SDValue Mullo2 = DAG.getNode(ISD::MUL, DL, VT, Neg_RHS, Add1);
1855     SDValue Mulhi2 = DAG.getNode(ISD::MULHU, DL, VT, Add1, Mullo2);
1856     SDValue Mulhi2_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1857                                     Zero);
1858     SDValue Mulhi2_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mulhi2,
1859                                     One);
1860 
1861     SDValue Add2_Lo = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_Lo,
1862                                   Mulhi2_Lo, Zero1);
1863     SDValue Add2_HiC = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add1_HiNc,
1864                                    Mulhi2_Hi, Add1_Lo.getValue(1));
1865     SDValue Add2_Hi = DAG.getNode(ISD::ADDCARRY, DL, HalfCarryVT, Add2_HiC,
1866                                   Zero, Add2_Lo.getValue(1));
1867     SDValue Add2 = DAG.getBitcast(VT,
1868                         DAG.getBuildVector(MVT::v2i32, DL, {Add2_Lo, Add2_Hi}));
1869     SDValue Mulhi3 = DAG.getNode(ISD::MULHU, DL, VT, LHS, Add2);
1870 
1871     SDValue Mul3 = DAG.getNode(ISD::MUL, DL, VT, RHS, Mulhi3);
1872 
1873     SDValue Mul3_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, Zero);
1874     SDValue Mul3_Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, Mul3, One);
1875     SDValue Sub1_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Lo,
1876                                   Mul3_Lo, Zero1);
1877     SDValue Sub1_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, LHS_Hi,
1878                                   Mul3_Hi, Sub1_Lo.getValue(1));
1879     SDValue Sub1_Mi = DAG.getNode(ISD::SUB, DL, HalfVT, LHS_Hi, Mul3_Hi);
1880     SDValue Sub1 = DAG.getBitcast(VT,
1881                         DAG.getBuildVector(MVT::v2i32, DL, {Sub1_Lo, Sub1_Hi}));
1882 
1883     SDValue MinusOne = DAG.getConstant(0xffffffffu, DL, HalfVT);
1884     SDValue C1 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, MinusOne, Zero,
1885                                  ISD::SETUGE);
1886     SDValue C2 = DAG.getSelectCC(DL, Sub1_Lo, RHS_Lo, MinusOne, Zero,
1887                                  ISD::SETUGE);
1888     SDValue C3 = DAG.getSelectCC(DL, Sub1_Hi, RHS_Hi, C2, C1, ISD::SETEQ);
1889 
1890     // TODO: Here and below portions of the code can be enclosed into if/endif.
1891     // Currently control flow is unconditional and we have 4 selects after
1892     // potential endif to substitute PHIs.
1893 
1894     // if C3 != 0 ...
1895     SDValue Sub2_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Lo,
1896                                   RHS_Lo, Zero1);
1897     SDValue Sub2_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub1_Mi,
1898                                   RHS_Hi, Sub1_Lo.getValue(1));
1899     SDValue Sub2_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1900                                   Zero, Sub2_Lo.getValue(1));
1901     SDValue Sub2 = DAG.getBitcast(VT,
1902                         DAG.getBuildVector(MVT::v2i32, DL, {Sub2_Lo, Sub2_Hi}));
1903 
1904     SDValue Add3 = DAG.getNode(ISD::ADD, DL, VT, Mulhi3, One64);
1905 
1906     SDValue C4 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, MinusOne, Zero,
1907                                  ISD::SETUGE);
1908     SDValue C5 = DAG.getSelectCC(DL, Sub2_Lo, RHS_Lo, MinusOne, Zero,
1909                                  ISD::SETUGE);
1910     SDValue C6 = DAG.getSelectCC(DL, Sub2_Hi, RHS_Hi, C5, C4, ISD::SETEQ);
1911 
1912     // if (C6 != 0)
1913     SDValue Add4 = DAG.getNode(ISD::ADD, DL, VT, Add3, One64);
1914 
1915     SDValue Sub3_Lo = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Lo,
1916                                   RHS_Lo, Zero1);
1917     SDValue Sub3_Mi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub2_Mi,
1918                                   RHS_Hi, Sub2_Lo.getValue(1));
1919     SDValue Sub3_Hi = DAG.getNode(ISD::SUBCARRY, DL, HalfCarryVT, Sub3_Mi,
1920                                   Zero, Sub3_Lo.getValue(1));
1921     SDValue Sub3 = DAG.getBitcast(VT,
1922                         DAG.getBuildVector(MVT::v2i32, DL, {Sub3_Lo, Sub3_Hi}));
1923 
1924     // endif C6
1925     // endif C3
1926 
1927     SDValue Sel1 = DAG.getSelectCC(DL, C6, Zero, Add4, Add3, ISD::SETNE);
1928     SDValue Div  = DAG.getSelectCC(DL, C3, Zero, Sel1, Mulhi3, ISD::SETNE);
1929 
1930     SDValue Sel2 = DAG.getSelectCC(DL, C6, Zero, Sub3, Sub2, ISD::SETNE);
1931     SDValue Rem  = DAG.getSelectCC(DL, C3, Zero, Sel2, Sub1, ISD::SETNE);
1932 
1933     Results.push_back(Div);
1934     Results.push_back(Rem);
1935 
1936     return;
1937   }
1938 
1939   // r600 expandion.
1940   // Get Speculative values
1941   SDValue DIV_Part = DAG.getNode(ISD::UDIV, DL, HalfVT, LHS_Hi, RHS_Lo);
1942   SDValue REM_Part = DAG.getNode(ISD::UREM, DL, HalfVT, LHS_Hi, RHS_Lo);
1943 
1944   SDValue REM_Lo = DAG.getSelectCC(DL, RHS_Hi, Zero, REM_Part, LHS_Hi, ISD::SETEQ);
1945   SDValue REM = DAG.getBuildVector(MVT::v2i32, DL, {REM_Lo, Zero});
1946   REM = DAG.getNode(ISD::BITCAST, DL, MVT::i64, REM);
1947 
1948   SDValue DIV_Hi = DAG.getSelectCC(DL, RHS_Hi, Zero, DIV_Part, Zero, ISD::SETEQ);
1949   SDValue DIV_Lo = Zero;
1950 
1951   const unsigned halfBitWidth = HalfVT.getSizeInBits();
1952 
1953   for (unsigned i = 0; i < halfBitWidth; ++i) {
1954     const unsigned bitPos = halfBitWidth - i - 1;
1955     SDValue POS = DAG.getConstant(bitPos, DL, HalfVT);
1956     // Get value of high bit
1957     SDValue HBit = DAG.getNode(ISD::SRL, DL, HalfVT, LHS_Lo, POS);
1958     HBit = DAG.getNode(ISD::AND, DL, HalfVT, HBit, One);
1959     HBit = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, HBit);
1960 
1961     // Shift
1962     REM = DAG.getNode(ISD::SHL, DL, VT, REM, DAG.getConstant(1, DL, VT));
1963     // Add LHS high bit
1964     REM = DAG.getNode(ISD::OR, DL, VT, REM, HBit);
1965 
1966     SDValue BIT = DAG.getConstant(1ULL << bitPos, DL, HalfVT);
1967     SDValue realBIT = DAG.getSelectCC(DL, REM, RHS, BIT, Zero, ISD::SETUGE);
1968 
1969     DIV_Lo = DAG.getNode(ISD::OR, DL, HalfVT, DIV_Lo, realBIT);
1970 
1971     // Update REM
1972     SDValue REM_sub = DAG.getNode(ISD::SUB, DL, VT, REM, RHS);
1973     REM = DAG.getSelectCC(DL, REM, RHS, REM_sub, REM, ISD::SETUGE);
1974   }
1975 
1976   SDValue DIV = DAG.getBuildVector(MVT::v2i32, DL, {DIV_Lo, DIV_Hi});
1977   DIV = DAG.getNode(ISD::BITCAST, DL, MVT::i64, DIV);
1978   Results.push_back(DIV);
1979   Results.push_back(REM);
1980 }
1981 
LowerUDIVREM(SDValue Op,SelectionDAG & DAG) const1982 SDValue AMDGPUTargetLowering::LowerUDIVREM(SDValue Op,
1983                                            SelectionDAG &DAG) const {
1984   SDLoc DL(Op);
1985   EVT VT = Op.getValueType();
1986 
1987   if (VT == MVT::i64) {
1988     SmallVector<SDValue, 2> Results;
1989     LowerUDIVREM64(Op, DAG, Results);
1990     return DAG.getMergeValues(Results, DL);
1991   }
1992 
1993   if (VT == MVT::i32) {
1994     if (SDValue Res = LowerDIVREM24(Op, DAG, false))
1995       return Res;
1996   }
1997 
1998   SDValue X = Op.getOperand(0);
1999   SDValue Y = Op.getOperand(1);
2000 
2001   // See AMDGPUCodeGenPrepare::expandDivRem32 for a description of the
2002   // algorithm used here.
2003 
2004   // Initial estimate of inv(y).
2005   SDValue Z = DAG.getNode(AMDGPUISD::URECIP, DL, VT, Y);
2006 
2007   // One round of UNR.
2008   SDValue NegY = DAG.getNode(ISD::SUB, DL, VT, DAG.getConstant(0, DL, VT), Y);
2009   SDValue NegYZ = DAG.getNode(ISD::MUL, DL, VT, NegY, Z);
2010   Z = DAG.getNode(ISD::ADD, DL, VT, Z,
2011                   DAG.getNode(ISD::MULHU, DL, VT, Z, NegYZ));
2012 
2013   // Quotient/remainder estimate.
2014   SDValue Q = DAG.getNode(ISD::MULHU, DL, VT, X, Z);
2015   SDValue R =
2016       DAG.getNode(ISD::SUB, DL, VT, X, DAG.getNode(ISD::MUL, DL, VT, Q, Y));
2017 
2018   // First quotient/remainder refinement.
2019   EVT CCVT = getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2020   SDValue One = DAG.getConstant(1, DL, VT);
2021   SDValue Cond = DAG.getSetCC(DL, CCVT, R, Y, ISD::SETUGE);
2022   Q = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2023                   DAG.getNode(ISD::ADD, DL, VT, Q, One), Q);
2024   R = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2025                   DAG.getNode(ISD::SUB, DL, VT, R, Y), R);
2026 
2027   // Second quotient/remainder refinement.
2028   Cond = DAG.getSetCC(DL, CCVT, R, Y, ISD::SETUGE);
2029   Q = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2030                   DAG.getNode(ISD::ADD, DL, VT, Q, One), Q);
2031   R = DAG.getNode(ISD::SELECT, DL, VT, Cond,
2032                   DAG.getNode(ISD::SUB, DL, VT, R, Y), R);
2033 
2034   return DAG.getMergeValues({Q, R}, DL);
2035 }
2036 
LowerSDIVREM(SDValue Op,SelectionDAG & DAG) const2037 SDValue AMDGPUTargetLowering::LowerSDIVREM(SDValue Op,
2038                                            SelectionDAG &DAG) const {
2039   SDLoc DL(Op);
2040   EVT VT = Op.getValueType();
2041 
2042   SDValue LHS = Op.getOperand(0);
2043   SDValue RHS = Op.getOperand(1);
2044 
2045   SDValue Zero = DAG.getConstant(0, DL, VT);
2046   SDValue NegOne = DAG.getConstant(-1, DL, VT);
2047 
2048   if (VT == MVT::i32) {
2049     if (SDValue Res = LowerDIVREM24(Op, DAG, true))
2050       return Res;
2051   }
2052 
2053   if (VT == MVT::i64 &&
2054       DAG.ComputeNumSignBits(LHS) > 32 &&
2055       DAG.ComputeNumSignBits(RHS) > 32) {
2056     EVT HalfVT = VT.getHalfSizedIntegerVT(*DAG.getContext());
2057 
2058     //HiLo split
2059     SDValue LHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, LHS, Zero);
2060     SDValue RHS_Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, DL, HalfVT, RHS, Zero);
2061     SDValue DIVREM = DAG.getNode(ISD::SDIVREM, DL, DAG.getVTList(HalfVT, HalfVT),
2062                                  LHS_Lo, RHS_Lo);
2063     SDValue Res[2] = {
2064       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(0)),
2065       DAG.getNode(ISD::SIGN_EXTEND, DL, VT, DIVREM.getValue(1))
2066     };
2067     return DAG.getMergeValues(Res, DL);
2068   }
2069 
2070   SDValue LHSign = DAG.getSelectCC(DL, LHS, Zero, NegOne, Zero, ISD::SETLT);
2071   SDValue RHSign = DAG.getSelectCC(DL, RHS, Zero, NegOne, Zero, ISD::SETLT);
2072   SDValue DSign = DAG.getNode(ISD::XOR, DL, VT, LHSign, RHSign);
2073   SDValue RSign = LHSign; // Remainder sign is the same as LHS
2074 
2075   LHS = DAG.getNode(ISD::ADD, DL, VT, LHS, LHSign);
2076   RHS = DAG.getNode(ISD::ADD, DL, VT, RHS, RHSign);
2077 
2078   LHS = DAG.getNode(ISD::XOR, DL, VT, LHS, LHSign);
2079   RHS = DAG.getNode(ISD::XOR, DL, VT, RHS, RHSign);
2080 
2081   SDValue Div = DAG.getNode(ISD::UDIVREM, DL, DAG.getVTList(VT, VT), LHS, RHS);
2082   SDValue Rem = Div.getValue(1);
2083 
2084   Div = DAG.getNode(ISD::XOR, DL, VT, Div, DSign);
2085   Rem = DAG.getNode(ISD::XOR, DL, VT, Rem, RSign);
2086 
2087   Div = DAG.getNode(ISD::SUB, DL, VT, Div, DSign);
2088   Rem = DAG.getNode(ISD::SUB, DL, VT, Rem, RSign);
2089 
2090   SDValue Res[2] = {
2091     Div,
2092     Rem
2093   };
2094   return DAG.getMergeValues(Res, DL);
2095 }
2096 
2097 // (frem x, y) -> (fma (fneg (ftrunc (fdiv x, y))), y, x)
LowerFREM(SDValue Op,SelectionDAG & DAG) const2098 SDValue AMDGPUTargetLowering::LowerFREM(SDValue Op, SelectionDAG &DAG) const {
2099   SDLoc SL(Op);
2100   EVT VT = Op.getValueType();
2101   auto Flags = Op->getFlags();
2102   SDValue X = Op.getOperand(0);
2103   SDValue Y = Op.getOperand(1);
2104 
2105   SDValue Div = DAG.getNode(ISD::FDIV, SL, VT, X, Y, Flags);
2106   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, VT, Div, Flags);
2107   SDValue Neg = DAG.getNode(ISD::FNEG, SL, VT, Trunc, Flags);
2108   // TODO: For f32 use FMAD instead if !hasFastFMA32?
2109   return DAG.getNode(ISD::FMA, SL, VT, Neg, Y, X, Flags);
2110 }
2111 
LowerFCEIL(SDValue Op,SelectionDAG & DAG) const2112 SDValue AMDGPUTargetLowering::LowerFCEIL(SDValue Op, SelectionDAG &DAG) const {
2113   SDLoc SL(Op);
2114   SDValue Src = Op.getOperand(0);
2115 
2116   // result = trunc(src)
2117   // if (src > 0.0 && src != result)
2118   //   result += 1.0
2119 
2120   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2121 
2122   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2123   const SDValue One = DAG.getConstantFP(1.0, SL, MVT::f64);
2124 
2125   EVT SetCCVT =
2126       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2127 
2128   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOGT);
2129   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2130   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2131 
2132   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, One, Zero);
2133   // TODO: Should this propagate fast-math-flags?
2134   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2135 }
2136 
extractF64Exponent(SDValue Hi,const SDLoc & SL,SelectionDAG & DAG)2137 static SDValue extractF64Exponent(SDValue Hi, const SDLoc &SL,
2138                                   SelectionDAG &DAG) {
2139   const unsigned FractBits = 52;
2140   const unsigned ExpBits = 11;
2141 
2142   SDValue ExpPart = DAG.getNode(AMDGPUISD::BFE_U32, SL, MVT::i32,
2143                                 Hi,
2144                                 DAG.getConstant(FractBits - 32, SL, MVT::i32),
2145                                 DAG.getConstant(ExpBits, SL, MVT::i32));
2146   SDValue Exp = DAG.getNode(ISD::SUB, SL, MVT::i32, ExpPart,
2147                             DAG.getConstant(1023, SL, MVT::i32));
2148 
2149   return Exp;
2150 }
2151 
LowerFTRUNC(SDValue Op,SelectionDAG & DAG) const2152 SDValue AMDGPUTargetLowering::LowerFTRUNC(SDValue Op, SelectionDAG &DAG) const {
2153   SDLoc SL(Op);
2154   SDValue Src = Op.getOperand(0);
2155 
2156   assert(Op.getValueType() == MVT::f64);
2157 
2158   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2159   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2160 
2161   SDValue VecSrc = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2162 
2163   // Extract the upper half, since this is where we will find the sign and
2164   // exponent.
2165   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecSrc, One);
2166 
2167   SDValue Exp = extractF64Exponent(Hi, SL, DAG);
2168 
2169   const unsigned FractBits = 52;
2170 
2171   // Extract the sign bit.
2172   const SDValue SignBitMask = DAG.getConstant(UINT32_C(1) << 31, SL, MVT::i32);
2173   SDValue SignBit = DAG.getNode(ISD::AND, SL, MVT::i32, Hi, SignBitMask);
2174 
2175   // Extend back to 64-bits.
2176   SDValue SignBit64 = DAG.getBuildVector(MVT::v2i32, SL, {Zero, SignBit});
2177   SignBit64 = DAG.getNode(ISD::BITCAST, SL, MVT::i64, SignBit64);
2178 
2179   SDValue BcInt = DAG.getNode(ISD::BITCAST, SL, MVT::i64, Src);
2180   const SDValue FractMask
2181     = DAG.getConstant((UINT64_C(1) << FractBits) - 1, SL, MVT::i64);
2182 
2183   SDValue Shr = DAG.getNode(ISD::SRA, SL, MVT::i64, FractMask, Exp);
2184   SDValue Not = DAG.getNOT(SL, Shr, MVT::i64);
2185   SDValue Tmp0 = DAG.getNode(ISD::AND, SL, MVT::i64, BcInt, Not);
2186 
2187   EVT SetCCVT =
2188       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::i32);
2189 
2190   const SDValue FiftyOne = DAG.getConstant(FractBits - 1, SL, MVT::i32);
2191 
2192   SDValue ExpLt0 = DAG.getSetCC(SL, SetCCVT, Exp, Zero, ISD::SETLT);
2193   SDValue ExpGt51 = DAG.getSetCC(SL, SetCCVT, Exp, FiftyOne, ISD::SETGT);
2194 
2195   SDValue Tmp1 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpLt0, SignBit64, Tmp0);
2196   SDValue Tmp2 = DAG.getNode(ISD::SELECT, SL, MVT::i64, ExpGt51, BcInt, Tmp1);
2197 
2198   return DAG.getNode(ISD::BITCAST, SL, MVT::f64, Tmp2);
2199 }
2200 
LowerFRINT(SDValue Op,SelectionDAG & DAG) const2201 SDValue AMDGPUTargetLowering::LowerFRINT(SDValue Op, SelectionDAG &DAG) const {
2202   SDLoc SL(Op);
2203   SDValue Src = Op.getOperand(0);
2204 
2205   assert(Op.getValueType() == MVT::f64);
2206 
2207   APFloat C1Val(APFloat::IEEEdouble(), "0x1.0p+52");
2208   SDValue C1 = DAG.getConstantFP(C1Val, SL, MVT::f64);
2209   SDValue CopySign = DAG.getNode(ISD::FCOPYSIGN, SL, MVT::f64, C1, Src);
2210 
2211   // TODO: Should this propagate fast-math-flags?
2212 
2213   SDValue Tmp1 = DAG.getNode(ISD::FADD, SL, MVT::f64, Src, CopySign);
2214   SDValue Tmp2 = DAG.getNode(ISD::FSUB, SL, MVT::f64, Tmp1, CopySign);
2215 
2216   SDValue Fabs = DAG.getNode(ISD::FABS, SL, MVT::f64, Src);
2217 
2218   APFloat C2Val(APFloat::IEEEdouble(), "0x1.fffffffffffffp+51");
2219   SDValue C2 = DAG.getConstantFP(C2Val, SL, MVT::f64);
2220 
2221   EVT SetCCVT =
2222       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2223   SDValue Cond = DAG.getSetCC(SL, SetCCVT, Fabs, C2, ISD::SETOGT);
2224 
2225   return DAG.getSelect(SL, MVT::f64, Cond, Src, Tmp2);
2226 }
2227 
LowerFNEARBYINT(SDValue Op,SelectionDAG & DAG) const2228 SDValue AMDGPUTargetLowering::LowerFNEARBYINT(SDValue Op, SelectionDAG &DAG) const {
2229   // FNEARBYINT and FRINT are the same, except in their handling of FP
2230   // exceptions. Those aren't really meaningful for us, and OpenCL only has
2231   // rint, so just treat them as equivalent.
2232   return DAG.getNode(ISD::FRINT, SDLoc(Op), Op.getValueType(), Op.getOperand(0));
2233 }
2234 
2235 // XXX - May require not supporting f32 denormals?
2236 
2237 // Don't handle v2f16. The extra instructions to scalarize and repack around the
2238 // compare and vselect end up producing worse code than scalarizing the whole
2239 // operation.
LowerFROUND(SDValue Op,SelectionDAG & DAG) const2240 SDValue AMDGPUTargetLowering::LowerFROUND(SDValue Op, SelectionDAG &DAG) const {
2241   SDLoc SL(Op);
2242   SDValue X = Op.getOperand(0);
2243   EVT VT = Op.getValueType();
2244 
2245   SDValue T = DAG.getNode(ISD::FTRUNC, SL, VT, X);
2246 
2247   // TODO: Should this propagate fast-math-flags?
2248 
2249   SDValue Diff = DAG.getNode(ISD::FSUB, SL, VT, X, T);
2250 
2251   SDValue AbsDiff = DAG.getNode(ISD::FABS, SL, VT, Diff);
2252 
2253   const SDValue Zero = DAG.getConstantFP(0.0, SL, VT);
2254   const SDValue One = DAG.getConstantFP(1.0, SL, VT);
2255   const SDValue Half = DAG.getConstantFP(0.5, SL, VT);
2256 
2257   SDValue SignOne = DAG.getNode(ISD::FCOPYSIGN, SL, VT, One, X);
2258 
2259   EVT SetCCVT =
2260       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), VT);
2261 
2262   SDValue Cmp = DAG.getSetCC(SL, SetCCVT, AbsDiff, Half, ISD::SETOGE);
2263 
2264   SDValue Sel = DAG.getNode(ISD::SELECT, SL, VT, Cmp, SignOne, Zero);
2265 
2266   return DAG.getNode(ISD::FADD, SL, VT, T, Sel);
2267 }
2268 
LowerFFLOOR(SDValue Op,SelectionDAG & DAG) const2269 SDValue AMDGPUTargetLowering::LowerFFLOOR(SDValue Op, SelectionDAG &DAG) const {
2270   SDLoc SL(Op);
2271   SDValue Src = Op.getOperand(0);
2272 
2273   // result = trunc(src);
2274   // if (src < 0.0 && src != result)
2275   //   result += -1.0.
2276 
2277   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2278 
2279   const SDValue Zero = DAG.getConstantFP(0.0, SL, MVT::f64);
2280   const SDValue NegOne = DAG.getConstantFP(-1.0, SL, MVT::f64);
2281 
2282   EVT SetCCVT =
2283       getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), MVT::f64);
2284 
2285   SDValue Lt0 = DAG.getSetCC(SL, SetCCVT, Src, Zero, ISD::SETOLT);
2286   SDValue NeTrunc = DAG.getSetCC(SL, SetCCVT, Src, Trunc, ISD::SETONE);
2287   SDValue And = DAG.getNode(ISD::AND, SL, SetCCVT, Lt0, NeTrunc);
2288 
2289   SDValue Add = DAG.getNode(ISD::SELECT, SL, MVT::f64, And, NegOne, Zero);
2290   // TODO: Should this propagate fast-math-flags?
2291   return DAG.getNode(ISD::FADD, SL, MVT::f64, Trunc, Add);
2292 }
2293 
LowerFLOG(SDValue Op,SelectionDAG & DAG,double Log2BaseInverted) const2294 SDValue AMDGPUTargetLowering::LowerFLOG(SDValue Op, SelectionDAG &DAG,
2295                                         double Log2BaseInverted) const {
2296   EVT VT = Op.getValueType();
2297 
2298   SDLoc SL(Op);
2299   SDValue Operand = Op.getOperand(0);
2300   SDValue Log2Operand = DAG.getNode(ISD::FLOG2, SL, VT, Operand);
2301   SDValue Log2BaseInvertedOperand = DAG.getConstantFP(Log2BaseInverted, SL, VT);
2302 
2303   return DAG.getNode(ISD::FMUL, SL, VT, Log2Operand, Log2BaseInvertedOperand);
2304 }
2305 
2306 // exp2(M_LOG2E_F * f);
lowerFEXP(SDValue Op,SelectionDAG & DAG) const2307 SDValue AMDGPUTargetLowering::lowerFEXP(SDValue Op, SelectionDAG &DAG) const {
2308   EVT VT = Op.getValueType();
2309   SDLoc SL(Op);
2310   SDValue Src = Op.getOperand(0);
2311 
2312   const SDValue K = DAG.getConstantFP(numbers::log2e, SL, VT);
2313   SDValue Mul = DAG.getNode(ISD::FMUL, SL, VT, Src, K, Op->getFlags());
2314   return DAG.getNode(ISD::FEXP2, SL, VT, Mul, Op->getFlags());
2315 }
2316 
isCtlzOpc(unsigned Opc)2317 static bool isCtlzOpc(unsigned Opc) {
2318   return Opc == ISD::CTLZ || Opc == ISD::CTLZ_ZERO_UNDEF;
2319 }
2320 
isCttzOpc(unsigned Opc)2321 static bool isCttzOpc(unsigned Opc) {
2322   return Opc == ISD::CTTZ || Opc == ISD::CTTZ_ZERO_UNDEF;
2323 }
2324 
LowerCTLZ_CTTZ(SDValue Op,SelectionDAG & DAG) const2325 SDValue AMDGPUTargetLowering::LowerCTLZ_CTTZ(SDValue Op, SelectionDAG &DAG) const {
2326   SDLoc SL(Op);
2327   SDValue Src = Op.getOperand(0);
2328   bool ZeroUndef = Op.getOpcode() == ISD::CTTZ_ZERO_UNDEF ||
2329                    Op.getOpcode() == ISD::CTLZ_ZERO_UNDEF;
2330 
2331   unsigned ISDOpc, NewOpc;
2332   if (isCtlzOpc(Op.getOpcode())) {
2333     ISDOpc = ISD::CTLZ_ZERO_UNDEF;
2334     NewOpc = AMDGPUISD::FFBH_U32;
2335   } else if (isCttzOpc(Op.getOpcode())) {
2336     ISDOpc = ISD::CTTZ_ZERO_UNDEF;
2337     NewOpc = AMDGPUISD::FFBL_B32;
2338   } else
2339     llvm_unreachable("Unexpected OPCode!!!");
2340 
2341 
2342   if (ZeroUndef && Src.getValueType() == MVT::i32)
2343     return DAG.getNode(NewOpc, SL, MVT::i32, Src);
2344 
2345   SDValue Vec = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2346 
2347   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
2348   const SDValue One = DAG.getConstant(1, SL, MVT::i32);
2349 
2350   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, Zero);
2351   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, Vec, One);
2352 
2353   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2354                                    *DAG.getContext(), MVT::i32);
2355 
2356   SDValue HiOrLo = isCtlzOpc(Op.getOpcode()) ? Hi : Lo;
2357   SDValue Hi0orLo0 = DAG.getSetCC(SL, SetCCVT, HiOrLo, Zero, ISD::SETEQ);
2358 
2359   SDValue OprLo = DAG.getNode(ISDOpc, SL, MVT::i32, Lo);
2360   SDValue OprHi = DAG.getNode(ISDOpc, SL, MVT::i32, Hi);
2361 
2362   const SDValue Bits32 = DAG.getConstant(32, SL, MVT::i32);
2363   SDValue Add, NewOpr;
2364   if (isCtlzOpc(Op.getOpcode())) {
2365     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprLo, Bits32);
2366     // ctlz(x) = hi_32(x) == 0 ? ctlz(lo_32(x)) + 32 : ctlz(hi_32(x))
2367     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprHi);
2368   } else {
2369     Add = DAG.getNode(ISD::ADD, SL, MVT::i32, OprHi, Bits32);
2370     // cttz(x) = lo_32(x) == 0 ? cttz(hi_32(x)) + 32 : cttz(lo_32(x))
2371     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32, Hi0orLo0, Add, OprLo);
2372   }
2373 
2374   if (!ZeroUndef) {
2375     // Test if the full 64-bit input is zero.
2376 
2377     // FIXME: DAG combines turn what should be an s_and_b64 into a v_or_b32,
2378     // which we probably don't want.
2379     SDValue LoOrHi = isCtlzOpc(Op.getOpcode()) ? Lo : Hi;
2380     SDValue Lo0OrHi0 = DAG.getSetCC(SL, SetCCVT, LoOrHi, Zero, ISD::SETEQ);
2381     SDValue SrcIsZero = DAG.getNode(ISD::AND, SL, SetCCVT, Lo0OrHi0, Hi0orLo0);
2382 
2383     // TODO: If i64 setcc is half rate, it can result in 1 fewer instruction
2384     // with the same cycles, otherwise it is slower.
2385     // SDValue SrcIsZero = DAG.getSetCC(SL, SetCCVT, Src,
2386     // DAG.getConstant(0, SL, MVT::i64), ISD::SETEQ);
2387 
2388     const SDValue Bits32 = DAG.getConstant(64, SL, MVT::i32);
2389 
2390     // The instruction returns -1 for 0 input, but the defined intrinsic
2391     // behavior is to return the number of bits.
2392     NewOpr = DAG.getNode(ISD::SELECT, SL, MVT::i32,
2393                          SrcIsZero, Bits32, NewOpr);
2394   }
2395 
2396   return DAG.getNode(ISD::ZERO_EXTEND, SL, MVT::i64, NewOpr);
2397 }
2398 
LowerINT_TO_FP32(SDValue Op,SelectionDAG & DAG,bool Signed) const2399 SDValue AMDGPUTargetLowering::LowerINT_TO_FP32(SDValue Op, SelectionDAG &DAG,
2400                                                bool Signed) const {
2401   // Unsigned
2402   // cul2f(ulong u)
2403   //{
2404   //  uint lz = clz(u);
2405   //  uint e = (u != 0) ? 127U + 63U - lz : 0;
2406   //  u = (u << lz) & 0x7fffffffffffffffUL;
2407   //  ulong t = u & 0xffffffffffUL;
2408   //  uint v = (e << 23) | (uint)(u >> 40);
2409   //  uint r = t > 0x8000000000UL ? 1U : (t == 0x8000000000UL ? v & 1U : 0U);
2410   //  return as_float(v + r);
2411   //}
2412   // Signed
2413   // cl2f(long l)
2414   //{
2415   //  long s = l >> 63;
2416   //  float r = cul2f((l + s) ^ s);
2417   //  return s ? -r : r;
2418   //}
2419 
2420   SDLoc SL(Op);
2421   SDValue Src = Op.getOperand(0);
2422   SDValue L = Src;
2423 
2424   SDValue S;
2425   if (Signed) {
2426     const SDValue SignBit = DAG.getConstant(63, SL, MVT::i64);
2427     S = DAG.getNode(ISD::SRA, SL, MVT::i64, L, SignBit);
2428 
2429     SDValue LPlusS = DAG.getNode(ISD::ADD, SL, MVT::i64, L, S);
2430     L = DAG.getNode(ISD::XOR, SL, MVT::i64, LPlusS, S);
2431   }
2432 
2433   EVT SetCCVT = getSetCCResultType(DAG.getDataLayout(),
2434                                    *DAG.getContext(), MVT::f32);
2435 
2436 
2437   SDValue ZeroI32 = DAG.getConstant(0, SL, MVT::i32);
2438   SDValue ZeroI64 = DAG.getConstant(0, SL, MVT::i64);
2439   SDValue LZ = DAG.getNode(ISD::CTLZ_ZERO_UNDEF, SL, MVT::i64, L);
2440   LZ = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LZ);
2441 
2442   SDValue K = DAG.getConstant(127U + 63U, SL, MVT::i32);
2443   SDValue E = DAG.getSelect(SL, MVT::i32,
2444     DAG.getSetCC(SL, SetCCVT, L, ZeroI64, ISD::SETNE),
2445     DAG.getNode(ISD::SUB, SL, MVT::i32, K, LZ),
2446     ZeroI32);
2447 
2448   SDValue U = DAG.getNode(ISD::AND, SL, MVT::i64,
2449     DAG.getNode(ISD::SHL, SL, MVT::i64, L, LZ),
2450     DAG.getConstant((-1ULL) >> 1, SL, MVT::i64));
2451 
2452   SDValue T = DAG.getNode(ISD::AND, SL, MVT::i64, U,
2453                           DAG.getConstant(0xffffffffffULL, SL, MVT::i64));
2454 
2455   SDValue UShl = DAG.getNode(ISD::SRL, SL, MVT::i64,
2456                              U, DAG.getConstant(40, SL, MVT::i64));
2457 
2458   SDValue V = DAG.getNode(ISD::OR, SL, MVT::i32,
2459     DAG.getNode(ISD::SHL, SL, MVT::i32, E, DAG.getConstant(23, SL, MVT::i32)),
2460     DAG.getNode(ISD::TRUNCATE, SL, MVT::i32,  UShl));
2461 
2462   SDValue C = DAG.getConstant(0x8000000000ULL, SL, MVT::i64);
2463   SDValue RCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETUGT);
2464   SDValue TCmp = DAG.getSetCC(SL, SetCCVT, T, C, ISD::SETEQ);
2465 
2466   SDValue One = DAG.getConstant(1, SL, MVT::i32);
2467 
2468   SDValue VTrunc1 = DAG.getNode(ISD::AND, SL, MVT::i32, V, One);
2469 
2470   SDValue R = DAG.getSelect(SL, MVT::i32,
2471     RCmp,
2472     One,
2473     DAG.getSelect(SL, MVT::i32, TCmp, VTrunc1, ZeroI32));
2474   R = DAG.getNode(ISD::ADD, SL, MVT::i32, V, R);
2475   R = DAG.getNode(ISD::BITCAST, SL, MVT::f32, R);
2476 
2477   if (!Signed)
2478     return R;
2479 
2480   SDValue RNeg = DAG.getNode(ISD::FNEG, SL, MVT::f32, R);
2481   return DAG.getSelect(SL, MVT::f32, DAG.getSExtOrTrunc(S, SL, SetCCVT), RNeg, R);
2482 }
2483 
LowerINT_TO_FP64(SDValue Op,SelectionDAG & DAG,bool Signed) const2484 SDValue AMDGPUTargetLowering::LowerINT_TO_FP64(SDValue Op, SelectionDAG &DAG,
2485                                                bool Signed) const {
2486   SDLoc SL(Op);
2487   SDValue Src = Op.getOperand(0);
2488 
2489   SDValue BC = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, Src);
2490 
2491   SDValue Lo = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2492                            DAG.getConstant(0, SL, MVT::i32));
2493   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, BC,
2494                            DAG.getConstant(1, SL, MVT::i32));
2495 
2496   SDValue CvtHi = DAG.getNode(Signed ? ISD::SINT_TO_FP : ISD::UINT_TO_FP,
2497                               SL, MVT::f64, Hi);
2498 
2499   SDValue CvtLo = DAG.getNode(ISD::UINT_TO_FP, SL, MVT::f64, Lo);
2500 
2501   SDValue LdExp = DAG.getNode(AMDGPUISD::LDEXP, SL, MVT::f64, CvtHi,
2502                               DAG.getConstant(32, SL, MVT::i32));
2503   // TODO: Should this propagate fast-math-flags?
2504   return DAG.getNode(ISD::FADD, SL, MVT::f64, LdExp, CvtLo);
2505 }
2506 
LowerUINT_TO_FP(SDValue Op,SelectionDAG & DAG) const2507 SDValue AMDGPUTargetLowering::LowerUINT_TO_FP(SDValue Op,
2508                                                SelectionDAG &DAG) const {
2509   // TODO: Factor out code common with LowerSINT_TO_FP.
2510   EVT DestVT = Op.getValueType();
2511   SDValue Src = Op.getOperand(0);
2512   EVT SrcVT = Src.getValueType();
2513 
2514   if (SrcVT == MVT::i16) {
2515     if (DestVT == MVT::f16)
2516       return Op;
2517     SDLoc DL(Op);
2518 
2519     // Promote src to i32
2520     SDValue Ext = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Src);
2521     return DAG.getNode(ISD::UINT_TO_FP, DL, DestVT, Ext);
2522   }
2523 
2524   assert(SrcVT == MVT::i64 && "operation should be legal");
2525 
2526   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2527     SDLoc DL(Op);
2528 
2529     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2530     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2531     SDValue FPRound =
2532         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2533 
2534     return FPRound;
2535   }
2536 
2537   if (DestVT == MVT::f32)
2538     return LowerINT_TO_FP32(Op, DAG, false);
2539 
2540   assert(DestVT == MVT::f64);
2541   return LowerINT_TO_FP64(Op, DAG, false);
2542 }
2543 
LowerSINT_TO_FP(SDValue Op,SelectionDAG & DAG) const2544 SDValue AMDGPUTargetLowering::LowerSINT_TO_FP(SDValue Op,
2545                                               SelectionDAG &DAG) const {
2546   EVT DestVT = Op.getValueType();
2547 
2548   SDValue Src = Op.getOperand(0);
2549   EVT SrcVT = Src.getValueType();
2550 
2551   if (SrcVT == MVT::i16) {
2552     if (DestVT == MVT::f16)
2553       return Op;
2554 
2555     SDLoc DL(Op);
2556     // Promote src to i32
2557     SDValue Ext = DAG.getNode(ISD::SIGN_EXTEND, DL, MVT::i32, Src);
2558     return DAG.getNode(ISD::SINT_TO_FP, DL, DestVT, Ext);
2559   }
2560 
2561   assert(SrcVT == MVT::i64 && "operation should be legal");
2562 
2563   // TODO: Factor out code common with LowerUINT_TO_FP.
2564 
2565   if (Subtarget->has16BitInsts() && DestVT == MVT::f16) {
2566     SDLoc DL(Op);
2567     SDValue Src = Op.getOperand(0);
2568 
2569     SDValue IntToFp32 = DAG.getNode(Op.getOpcode(), DL, MVT::f32, Src);
2570     SDValue FPRoundFlag = DAG.getIntPtrConstant(0, SDLoc(Op));
2571     SDValue FPRound =
2572         DAG.getNode(ISD::FP_ROUND, DL, MVT::f16, IntToFp32, FPRoundFlag);
2573 
2574     return FPRound;
2575   }
2576 
2577   if (DestVT == MVT::f32)
2578     return LowerINT_TO_FP32(Op, DAG, true);
2579 
2580   assert(DestVT == MVT::f64);
2581   return LowerINT_TO_FP64(Op, DAG, true);
2582 }
2583 
LowerFP64_TO_INT(SDValue Op,SelectionDAG & DAG,bool Signed) const2584 SDValue AMDGPUTargetLowering::LowerFP64_TO_INT(SDValue Op, SelectionDAG &DAG,
2585                                                bool Signed) const {
2586   SDLoc SL(Op);
2587 
2588   SDValue Src = Op.getOperand(0);
2589 
2590   SDValue Trunc = DAG.getNode(ISD::FTRUNC, SL, MVT::f64, Src);
2591 
2592   SDValue K0 = DAG.getConstantFP(BitsToDouble(UINT64_C(0x3df0000000000000)), SL,
2593                                  MVT::f64);
2594   SDValue K1 = DAG.getConstantFP(BitsToDouble(UINT64_C(0xc1f0000000000000)), SL,
2595                                  MVT::f64);
2596   // TODO: Should this propagate fast-math-flags?
2597   SDValue Mul = DAG.getNode(ISD::FMUL, SL, MVT::f64, Trunc, K0);
2598 
2599   SDValue FloorMul = DAG.getNode(ISD::FFLOOR, SL, MVT::f64, Mul);
2600 
2601 
2602   SDValue Fma = DAG.getNode(ISD::FMA, SL, MVT::f64, FloorMul, K1, Trunc);
2603 
2604   SDValue Hi = DAG.getNode(Signed ? ISD::FP_TO_SINT : ISD::FP_TO_UINT, SL,
2605                            MVT::i32, FloorMul);
2606   SDValue Lo = DAG.getNode(ISD::FP_TO_UINT, SL, MVT::i32, Fma);
2607 
2608   SDValue Result = DAG.getBuildVector(MVT::v2i32, SL, {Lo, Hi});
2609 
2610   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Result);
2611 }
2612 
LowerFP_TO_FP16(SDValue Op,SelectionDAG & DAG) const2613 SDValue AMDGPUTargetLowering::LowerFP_TO_FP16(SDValue Op, SelectionDAG &DAG) const {
2614   SDLoc DL(Op);
2615   SDValue N0 = Op.getOperand(0);
2616 
2617   // Convert to target node to get known bits
2618   if (N0.getValueType() == MVT::f32)
2619     return DAG.getNode(AMDGPUISD::FP_TO_FP16, DL, Op.getValueType(), N0);
2620 
2621   if (getTargetMachine().Options.UnsafeFPMath) {
2622     // There is a generic expand for FP_TO_FP16 with unsafe fast math.
2623     return SDValue();
2624   }
2625 
2626   assert(N0.getSimpleValueType() == MVT::f64);
2627 
2628   // f64 -> f16 conversion using round-to-nearest-even rounding mode.
2629   const unsigned ExpMask = 0x7ff;
2630   const unsigned ExpBiasf64 = 1023;
2631   const unsigned ExpBiasf16 = 15;
2632   SDValue Zero = DAG.getConstant(0, DL, MVT::i32);
2633   SDValue One = DAG.getConstant(1, DL, MVT::i32);
2634   SDValue U = DAG.getNode(ISD::BITCAST, DL, MVT::i64, N0);
2635   SDValue UH = DAG.getNode(ISD::SRL, DL, MVT::i64, U,
2636                            DAG.getConstant(32, DL, MVT::i64));
2637   UH = DAG.getZExtOrTrunc(UH, DL, MVT::i32);
2638   U = DAG.getZExtOrTrunc(U, DL, MVT::i32);
2639   SDValue E = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2640                           DAG.getConstant(20, DL, MVT::i64));
2641   E = DAG.getNode(ISD::AND, DL, MVT::i32, E,
2642                   DAG.getConstant(ExpMask, DL, MVT::i32));
2643   // Subtract the fp64 exponent bias (1023) to get the real exponent and
2644   // add the f16 bias (15) to get the biased exponent for the f16 format.
2645   E = DAG.getNode(ISD::ADD, DL, MVT::i32, E,
2646                   DAG.getConstant(-ExpBiasf64 + ExpBiasf16, DL, MVT::i32));
2647 
2648   SDValue M = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2649                           DAG.getConstant(8, DL, MVT::i32));
2650   M = DAG.getNode(ISD::AND, DL, MVT::i32, M,
2651                   DAG.getConstant(0xffe, DL, MVT::i32));
2652 
2653   SDValue MaskedSig = DAG.getNode(ISD::AND, DL, MVT::i32, UH,
2654                                   DAG.getConstant(0x1ff, DL, MVT::i32));
2655   MaskedSig = DAG.getNode(ISD::OR, DL, MVT::i32, MaskedSig, U);
2656 
2657   SDValue Lo40Set = DAG.getSelectCC(DL, MaskedSig, Zero, Zero, One, ISD::SETEQ);
2658   M = DAG.getNode(ISD::OR, DL, MVT::i32, M, Lo40Set);
2659 
2660   // (M != 0 ? 0x0200 : 0) | 0x7c00;
2661   SDValue I = DAG.getNode(ISD::OR, DL, MVT::i32,
2662       DAG.getSelectCC(DL, M, Zero, DAG.getConstant(0x0200, DL, MVT::i32),
2663                       Zero, ISD::SETNE), DAG.getConstant(0x7c00, DL, MVT::i32));
2664 
2665   // N = M | (E << 12);
2666   SDValue N = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2667       DAG.getNode(ISD::SHL, DL, MVT::i32, E,
2668                   DAG.getConstant(12, DL, MVT::i32)));
2669 
2670   // B = clamp(1-E, 0, 13);
2671   SDValue OneSubExp = DAG.getNode(ISD::SUB, DL, MVT::i32,
2672                                   One, E);
2673   SDValue B = DAG.getNode(ISD::SMAX, DL, MVT::i32, OneSubExp, Zero);
2674   B = DAG.getNode(ISD::SMIN, DL, MVT::i32, B,
2675                   DAG.getConstant(13, DL, MVT::i32));
2676 
2677   SDValue SigSetHigh = DAG.getNode(ISD::OR, DL, MVT::i32, M,
2678                                    DAG.getConstant(0x1000, DL, MVT::i32));
2679 
2680   SDValue D = DAG.getNode(ISD::SRL, DL, MVT::i32, SigSetHigh, B);
2681   SDValue D0 = DAG.getNode(ISD::SHL, DL, MVT::i32, D, B);
2682   SDValue D1 = DAG.getSelectCC(DL, D0, SigSetHigh, One, Zero, ISD::SETNE);
2683   D = DAG.getNode(ISD::OR, DL, MVT::i32, D, D1);
2684 
2685   SDValue V = DAG.getSelectCC(DL, E, One, D, N, ISD::SETLT);
2686   SDValue VLow3 = DAG.getNode(ISD::AND, DL, MVT::i32, V,
2687                               DAG.getConstant(0x7, DL, MVT::i32));
2688   V = DAG.getNode(ISD::SRL, DL, MVT::i32, V,
2689                   DAG.getConstant(2, DL, MVT::i32));
2690   SDValue V0 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(3, DL, MVT::i32),
2691                                One, Zero, ISD::SETEQ);
2692   SDValue V1 = DAG.getSelectCC(DL, VLow3, DAG.getConstant(5, DL, MVT::i32),
2693                                One, Zero, ISD::SETGT);
2694   V1 = DAG.getNode(ISD::OR, DL, MVT::i32, V0, V1);
2695   V = DAG.getNode(ISD::ADD, DL, MVT::i32, V, V1);
2696 
2697   V = DAG.getSelectCC(DL, E, DAG.getConstant(30, DL, MVT::i32),
2698                       DAG.getConstant(0x7c00, DL, MVT::i32), V, ISD::SETGT);
2699   V = DAG.getSelectCC(DL, E, DAG.getConstant(1039, DL, MVT::i32),
2700                       I, V, ISD::SETEQ);
2701 
2702   // Extract the sign bit.
2703   SDValue Sign = DAG.getNode(ISD::SRL, DL, MVT::i32, UH,
2704                             DAG.getConstant(16, DL, MVT::i32));
2705   Sign = DAG.getNode(ISD::AND, DL, MVT::i32, Sign,
2706                      DAG.getConstant(0x8000, DL, MVT::i32));
2707 
2708   V = DAG.getNode(ISD::OR, DL, MVT::i32, Sign, V);
2709   return DAG.getZExtOrTrunc(V, DL, Op.getValueType());
2710 }
2711 
LowerFP_TO_INT(SDValue Op,SelectionDAG & DAG) const2712 SDValue AMDGPUTargetLowering::LowerFP_TO_INT(SDValue Op,
2713                                              SelectionDAG &DAG) const {
2714   SDValue Src = Op.getOperand(0);
2715   unsigned OpOpcode = Op.getOpcode();
2716   EVT SrcVT = Src.getValueType();
2717   EVT DestVT = Op.getValueType();
2718 
2719   // Will be selected natively
2720   if (SrcVT == MVT::f16 && DestVT == MVT::i16)
2721     return Op;
2722 
2723   // Promote i16 to i32
2724   if (DestVT == MVT::i16 && (SrcVT == MVT::f32 || SrcVT == MVT::f64)) {
2725     SDLoc DL(Op);
2726 
2727     SDValue FpToInt32 = DAG.getNode(OpOpcode, DL, MVT::i32, Src);
2728     return DAG.getNode(ISD::TRUNCATE, DL, MVT::i16, FpToInt32);
2729   }
2730 
2731   if (SrcVT == MVT::f16 ||
2732       (SrcVT == MVT::f32 && Src.getOpcode() == ISD::FP16_TO_FP)) {
2733     SDLoc DL(Op);
2734 
2735     SDValue FpToInt32 = DAG.getNode(OpOpcode, DL, MVT::i32, Src);
2736     unsigned Ext =
2737         OpOpcode == ISD::FP_TO_SINT ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND;
2738     return DAG.getNode(Ext, DL, MVT::i64, FpToInt32);
2739   }
2740 
2741   if (DestVT == MVT::i64 && SrcVT == MVT::f64)
2742     return LowerFP64_TO_INT(Op, DAG, OpOpcode == ISD::FP_TO_SINT);
2743 
2744   return SDValue();
2745 }
2746 
LowerSIGN_EXTEND_INREG(SDValue Op,SelectionDAG & DAG) const2747 SDValue AMDGPUTargetLowering::LowerSIGN_EXTEND_INREG(SDValue Op,
2748                                                      SelectionDAG &DAG) const {
2749   EVT ExtraVT = cast<VTSDNode>(Op.getOperand(1))->getVT();
2750   MVT VT = Op.getSimpleValueType();
2751   MVT ScalarVT = VT.getScalarType();
2752 
2753   assert(VT.isVector());
2754 
2755   SDValue Src = Op.getOperand(0);
2756   SDLoc DL(Op);
2757 
2758   // TODO: Don't scalarize on Evergreen?
2759   unsigned NElts = VT.getVectorNumElements();
2760   SmallVector<SDValue, 8> Args;
2761   DAG.ExtractVectorElements(Src, Args, 0, NElts);
2762 
2763   SDValue VTOp = DAG.getValueType(ExtraVT.getScalarType());
2764   for (unsigned I = 0; I < NElts; ++I)
2765     Args[I] = DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, ScalarVT, Args[I], VTOp);
2766 
2767   return DAG.getBuildVector(VT, DL, Args);
2768 }
2769 
2770 //===----------------------------------------------------------------------===//
2771 // Custom DAG optimizations
2772 //===----------------------------------------------------------------------===//
2773 
isU24(SDValue Op,SelectionDAG & DAG)2774 static bool isU24(SDValue Op, SelectionDAG &DAG) {
2775   return AMDGPUTargetLowering::numBitsUnsigned(Op, DAG) <= 24;
2776 }
2777 
isI24(SDValue Op,SelectionDAG & DAG)2778 static bool isI24(SDValue Op, SelectionDAG &DAG) {
2779   EVT VT = Op.getValueType();
2780   return VT.getSizeInBits() >= 24 && // Types less than 24-bit should be treated
2781                                      // as unsigned 24-bit values.
2782     AMDGPUTargetLowering::numBitsSigned(Op, DAG) < 24;
2783 }
2784 
simplifyMul24(SDNode * Node24,TargetLowering::DAGCombinerInfo & DCI)2785 static SDValue simplifyMul24(SDNode *Node24,
2786                              TargetLowering::DAGCombinerInfo &DCI) {
2787   SelectionDAG &DAG = DCI.DAG;
2788   const TargetLowering &TLI = DAG.getTargetLoweringInfo();
2789   bool IsIntrin = Node24->getOpcode() == ISD::INTRINSIC_WO_CHAIN;
2790 
2791   SDValue LHS = IsIntrin ? Node24->getOperand(1) : Node24->getOperand(0);
2792   SDValue RHS = IsIntrin ? Node24->getOperand(2) : Node24->getOperand(1);
2793   unsigned NewOpcode = Node24->getOpcode();
2794   if (IsIntrin) {
2795     unsigned IID = cast<ConstantSDNode>(Node24->getOperand(0))->getZExtValue();
2796     NewOpcode = IID == Intrinsic::amdgcn_mul_i24 ?
2797       AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
2798   }
2799 
2800   APInt Demanded = APInt::getLowBitsSet(LHS.getValueSizeInBits(), 24);
2801 
2802   // First try to simplify using SimplifyMultipleUseDemandedBits which allows
2803   // the operands to have other uses, but will only perform simplifications that
2804   // involve bypassing some nodes for this user.
2805   SDValue DemandedLHS = TLI.SimplifyMultipleUseDemandedBits(LHS, Demanded, DAG);
2806   SDValue DemandedRHS = TLI.SimplifyMultipleUseDemandedBits(RHS, Demanded, DAG);
2807   if (DemandedLHS || DemandedRHS)
2808     return DAG.getNode(NewOpcode, SDLoc(Node24), Node24->getVTList(),
2809                        DemandedLHS ? DemandedLHS : LHS,
2810                        DemandedRHS ? DemandedRHS : RHS);
2811 
2812   // Now try SimplifyDemandedBits which can simplify the nodes used by our
2813   // operands if this node is the only user.
2814   if (TLI.SimplifyDemandedBits(LHS, Demanded, DCI))
2815     return SDValue(Node24, 0);
2816   if (TLI.SimplifyDemandedBits(RHS, Demanded, DCI))
2817     return SDValue(Node24, 0);
2818 
2819   return SDValue();
2820 }
2821 
2822 template <typename IntTy>
constantFoldBFE(SelectionDAG & DAG,IntTy Src0,uint32_t Offset,uint32_t Width,const SDLoc & DL)2823 static SDValue constantFoldBFE(SelectionDAG &DAG, IntTy Src0, uint32_t Offset,
2824                                uint32_t Width, const SDLoc &DL) {
2825   if (Width + Offset < 32) {
2826     uint32_t Shl = static_cast<uint32_t>(Src0) << (32 - Offset - Width);
2827     IntTy Result = static_cast<IntTy>(Shl) >> (32 - Width);
2828     return DAG.getConstant(Result, DL, MVT::i32);
2829   }
2830 
2831   return DAG.getConstant(Src0 >> Offset, DL, MVT::i32);
2832 }
2833 
hasVolatileUser(SDNode * Val)2834 static bool hasVolatileUser(SDNode *Val) {
2835   for (SDNode *U : Val->uses()) {
2836     if (MemSDNode *M = dyn_cast<MemSDNode>(U)) {
2837       if (M->isVolatile())
2838         return true;
2839     }
2840   }
2841 
2842   return false;
2843 }
2844 
shouldCombineMemoryType(EVT VT) const2845 bool AMDGPUTargetLowering::shouldCombineMemoryType(EVT VT) const {
2846   // i32 vectors are the canonical memory type.
2847   if (VT.getScalarType() == MVT::i32 || isTypeLegal(VT))
2848     return false;
2849 
2850   if (!VT.isByteSized())
2851     return false;
2852 
2853   unsigned Size = VT.getStoreSize();
2854 
2855   if ((Size == 1 || Size == 2 || Size == 4) && !VT.isVector())
2856     return false;
2857 
2858   if (Size == 3 || (Size > 4 && (Size % 4 != 0)))
2859     return false;
2860 
2861   return true;
2862 }
2863 
2864 // Replace load of an illegal type with a store of a bitcast to a friendlier
2865 // type.
performLoadCombine(SDNode * N,DAGCombinerInfo & DCI) const2866 SDValue AMDGPUTargetLowering::performLoadCombine(SDNode *N,
2867                                                  DAGCombinerInfo &DCI) const {
2868   if (!DCI.isBeforeLegalize())
2869     return SDValue();
2870 
2871   LoadSDNode *LN = cast<LoadSDNode>(N);
2872   if (!LN->isSimple() || !ISD::isNormalLoad(LN) || hasVolatileUser(LN))
2873     return SDValue();
2874 
2875   SDLoc SL(N);
2876   SelectionDAG &DAG = DCI.DAG;
2877   EVT VT = LN->getMemoryVT();
2878 
2879   unsigned Size = VT.getStoreSize();
2880   Align Alignment = LN->getAlign();
2881   if (Alignment < Size && isTypeLegal(VT)) {
2882     bool IsFast;
2883     unsigned AS = LN->getAddressSpace();
2884 
2885     // Expand unaligned loads earlier than legalization. Due to visitation order
2886     // problems during legalization, the emitted instructions to pack and unpack
2887     // the bytes again are not eliminated in the case of an unaligned copy.
2888     if (!allowsMisalignedMemoryAccesses(
2889             VT, AS, Alignment, LN->getMemOperand()->getFlags(), &IsFast)) {
2890       SDValue Ops[2];
2891 
2892       if (VT.isVector())
2893         std::tie(Ops[0], Ops[1]) = scalarizeVectorLoad(LN, DAG);
2894       else
2895         std::tie(Ops[0], Ops[1]) = expandUnalignedLoad(LN, DAG);
2896 
2897       return DAG.getMergeValues(Ops, SDLoc(N));
2898     }
2899 
2900     if (!IsFast)
2901       return SDValue();
2902   }
2903 
2904   if (!shouldCombineMemoryType(VT))
2905     return SDValue();
2906 
2907   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2908 
2909   SDValue NewLoad
2910     = DAG.getLoad(NewVT, SL, LN->getChain(),
2911                   LN->getBasePtr(), LN->getMemOperand());
2912 
2913   SDValue BC = DAG.getNode(ISD::BITCAST, SL, VT, NewLoad);
2914   DCI.CombineTo(N, BC, NewLoad.getValue(1));
2915   return SDValue(N, 0);
2916 }
2917 
2918 // Replace store of an illegal type with a store of a bitcast to a friendlier
2919 // type.
performStoreCombine(SDNode * N,DAGCombinerInfo & DCI) const2920 SDValue AMDGPUTargetLowering::performStoreCombine(SDNode *N,
2921                                                   DAGCombinerInfo &DCI) const {
2922   if (!DCI.isBeforeLegalize())
2923     return SDValue();
2924 
2925   StoreSDNode *SN = cast<StoreSDNode>(N);
2926   if (!SN->isSimple() || !ISD::isNormalStore(SN))
2927     return SDValue();
2928 
2929   EVT VT = SN->getMemoryVT();
2930   unsigned Size = VT.getStoreSize();
2931 
2932   SDLoc SL(N);
2933   SelectionDAG &DAG = DCI.DAG;
2934   Align Alignment = SN->getAlign();
2935   if (Alignment < Size && isTypeLegal(VT)) {
2936     bool IsFast;
2937     unsigned AS = SN->getAddressSpace();
2938 
2939     // Expand unaligned stores earlier than legalization. Due to visitation
2940     // order problems during legalization, the emitted instructions to pack and
2941     // unpack the bytes again are not eliminated in the case of an unaligned
2942     // copy.
2943     if (!allowsMisalignedMemoryAccesses(
2944             VT, AS, Alignment, SN->getMemOperand()->getFlags(), &IsFast)) {
2945       if (VT.isVector())
2946         return scalarizeVectorStore(SN, DAG);
2947 
2948       return expandUnalignedStore(SN, DAG);
2949     }
2950 
2951     if (!IsFast)
2952       return SDValue();
2953   }
2954 
2955   if (!shouldCombineMemoryType(VT))
2956     return SDValue();
2957 
2958   EVT NewVT = getEquivalentMemType(*DAG.getContext(), VT);
2959   SDValue Val = SN->getValue();
2960 
2961   //DCI.AddToWorklist(Val.getNode());
2962 
2963   bool OtherUses = !Val.hasOneUse();
2964   SDValue CastVal = DAG.getNode(ISD::BITCAST, SL, NewVT, Val);
2965   if (OtherUses) {
2966     SDValue CastBack = DAG.getNode(ISD::BITCAST, SL, VT, CastVal);
2967     DAG.ReplaceAllUsesOfValueWith(Val, CastBack);
2968   }
2969 
2970   return DAG.getStore(SN->getChain(), SL, CastVal,
2971                       SN->getBasePtr(), SN->getMemOperand());
2972 }
2973 
2974 // FIXME: This should go in generic DAG combiner with an isTruncateFree check,
2975 // but isTruncateFree is inaccurate for i16 now because of SALU vs. VALU
2976 // issues.
performAssertSZExtCombine(SDNode * N,DAGCombinerInfo & DCI) const2977 SDValue AMDGPUTargetLowering::performAssertSZExtCombine(SDNode *N,
2978                                                         DAGCombinerInfo &DCI) const {
2979   SelectionDAG &DAG = DCI.DAG;
2980   SDValue N0 = N->getOperand(0);
2981 
2982   // (vt2 (assertzext (truncate vt0:x), vt1)) ->
2983   //     (vt2 (truncate (assertzext vt0:x, vt1)))
2984   if (N0.getOpcode() == ISD::TRUNCATE) {
2985     SDValue N1 = N->getOperand(1);
2986     EVT ExtVT = cast<VTSDNode>(N1)->getVT();
2987     SDLoc SL(N);
2988 
2989     SDValue Src = N0.getOperand(0);
2990     EVT SrcVT = Src.getValueType();
2991     if (SrcVT.bitsGE(ExtVT)) {
2992       SDValue NewInReg = DAG.getNode(N->getOpcode(), SL, SrcVT, Src, N1);
2993       return DAG.getNode(ISD::TRUNCATE, SL, N->getValueType(0), NewInReg);
2994     }
2995   }
2996 
2997   return SDValue();
2998 }
2999 
performIntrinsicWOChainCombine(SDNode * N,DAGCombinerInfo & DCI) const3000 SDValue AMDGPUTargetLowering::performIntrinsicWOChainCombine(
3001   SDNode *N, DAGCombinerInfo &DCI) const {
3002   unsigned IID = cast<ConstantSDNode>(N->getOperand(0))->getZExtValue();
3003   switch (IID) {
3004   case Intrinsic::amdgcn_mul_i24:
3005   case Intrinsic::amdgcn_mul_u24:
3006     return simplifyMul24(N, DCI);
3007   case Intrinsic::amdgcn_fract:
3008   case Intrinsic::amdgcn_rsq:
3009   case Intrinsic::amdgcn_rcp_legacy:
3010   case Intrinsic::amdgcn_rsq_legacy:
3011   case Intrinsic::amdgcn_rsq_clamp:
3012   case Intrinsic::amdgcn_ldexp: {
3013     // FIXME: This is probably wrong. If src is an sNaN, it won't be quieted
3014     SDValue Src = N->getOperand(1);
3015     return Src.isUndef() ? Src : SDValue();
3016   }
3017   default:
3018     return SDValue();
3019   }
3020 }
3021 
3022 /// Split the 64-bit value \p LHS into two 32-bit components, and perform the
3023 /// binary operation \p Opc to it with the corresponding constant operands.
splitBinaryBitConstantOpImpl(DAGCombinerInfo & DCI,const SDLoc & SL,unsigned Opc,SDValue LHS,uint32_t ValLo,uint32_t ValHi) const3024 SDValue AMDGPUTargetLowering::splitBinaryBitConstantOpImpl(
3025   DAGCombinerInfo &DCI, const SDLoc &SL,
3026   unsigned Opc, SDValue LHS,
3027   uint32_t ValLo, uint32_t ValHi) const {
3028   SelectionDAG &DAG = DCI.DAG;
3029   SDValue Lo, Hi;
3030   std::tie(Lo, Hi) = split64BitValue(LHS, DAG);
3031 
3032   SDValue LoRHS = DAG.getConstant(ValLo, SL, MVT::i32);
3033   SDValue HiRHS = DAG.getConstant(ValHi, SL, MVT::i32);
3034 
3035   SDValue LoAnd = DAG.getNode(Opc, SL, MVT::i32, Lo, LoRHS);
3036   SDValue HiAnd = DAG.getNode(Opc, SL, MVT::i32, Hi, HiRHS);
3037 
3038   // Re-visit the ands. It's possible we eliminated one of them and it could
3039   // simplify the vector.
3040   DCI.AddToWorklist(Lo.getNode());
3041   DCI.AddToWorklist(Hi.getNode());
3042 
3043   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {LoAnd, HiAnd});
3044   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
3045 }
3046 
performShlCombine(SDNode * N,DAGCombinerInfo & DCI) const3047 SDValue AMDGPUTargetLowering::performShlCombine(SDNode *N,
3048                                                 DAGCombinerInfo &DCI) const {
3049   EVT VT = N->getValueType(0);
3050 
3051   ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3052   if (!RHS)
3053     return SDValue();
3054 
3055   SDValue LHS = N->getOperand(0);
3056   unsigned RHSVal = RHS->getZExtValue();
3057   if (!RHSVal)
3058     return LHS;
3059 
3060   SDLoc SL(N);
3061   SelectionDAG &DAG = DCI.DAG;
3062 
3063   switch (LHS->getOpcode()) {
3064   default:
3065     break;
3066   case ISD::ZERO_EXTEND:
3067   case ISD::SIGN_EXTEND:
3068   case ISD::ANY_EXTEND: {
3069     SDValue X = LHS->getOperand(0);
3070 
3071     if (VT == MVT::i32 && RHSVal == 16 && X.getValueType() == MVT::i16 &&
3072         isOperationLegal(ISD::BUILD_VECTOR, MVT::v2i16)) {
3073       // Prefer build_vector as the canonical form if packed types are legal.
3074       // (shl ([asz]ext i16:x), 16 -> build_vector 0, x
3075       SDValue Vec = DAG.getBuildVector(MVT::v2i16, SL,
3076        { DAG.getConstant(0, SL, MVT::i16), LHS->getOperand(0) });
3077       return DAG.getNode(ISD::BITCAST, SL, MVT::i32, Vec);
3078     }
3079 
3080     // shl (ext x) => zext (shl x), if shift does not overflow int
3081     if (VT != MVT::i64)
3082       break;
3083     KnownBits Known = DAG.computeKnownBits(X);
3084     unsigned LZ = Known.countMinLeadingZeros();
3085     if (LZ < RHSVal)
3086       break;
3087     EVT XVT = X.getValueType();
3088     SDValue Shl = DAG.getNode(ISD::SHL, SL, XVT, X, SDValue(RHS, 0));
3089     return DAG.getZExtOrTrunc(Shl, SL, VT);
3090   }
3091   }
3092 
3093   if (VT != MVT::i64)
3094     return SDValue();
3095 
3096   // i64 (shl x, C) -> (build_pair 0, (shl x, C -32))
3097 
3098   // On some subtargets, 64-bit shift is a quarter rate instruction. In the
3099   // common case, splitting this into a move and a 32-bit shift is faster and
3100   // the same code size.
3101   if (RHSVal < 32)
3102     return SDValue();
3103 
3104   SDValue ShiftAmt = DAG.getConstant(RHSVal - 32, SL, MVT::i32);
3105 
3106   SDValue Lo = DAG.getNode(ISD::TRUNCATE, SL, MVT::i32, LHS);
3107   SDValue NewShift = DAG.getNode(ISD::SHL, SL, MVT::i32, Lo, ShiftAmt);
3108 
3109   const SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3110 
3111   SDValue Vec = DAG.getBuildVector(MVT::v2i32, SL, {Zero, NewShift});
3112   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, Vec);
3113 }
3114 
performSraCombine(SDNode * N,DAGCombinerInfo & DCI) const3115 SDValue AMDGPUTargetLowering::performSraCombine(SDNode *N,
3116                                                 DAGCombinerInfo &DCI) const {
3117   if (N->getValueType(0) != MVT::i64)
3118     return SDValue();
3119 
3120   const ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3121   if (!RHS)
3122     return SDValue();
3123 
3124   SelectionDAG &DAG = DCI.DAG;
3125   SDLoc SL(N);
3126   unsigned RHSVal = RHS->getZExtValue();
3127 
3128   // (sra i64:x, 32) -> build_pair x, (sra hi_32(x), 31)
3129   if (RHSVal == 32) {
3130     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3131     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3132                                    DAG.getConstant(31, SL, MVT::i32));
3133 
3134     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {Hi, NewShift});
3135     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3136   }
3137 
3138   // (sra i64:x, 63) -> build_pair (sra hi_32(x), 31), (sra hi_32(x), 31)
3139   if (RHSVal == 63) {
3140     SDValue Hi = getHiHalf64(N->getOperand(0), DAG);
3141     SDValue NewShift = DAG.getNode(ISD::SRA, SL, MVT::i32, Hi,
3142                                    DAG.getConstant(31, SL, MVT::i32));
3143     SDValue BuildVec = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, NewShift});
3144     return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildVec);
3145   }
3146 
3147   return SDValue();
3148 }
3149 
performSrlCombine(SDNode * N,DAGCombinerInfo & DCI) const3150 SDValue AMDGPUTargetLowering::performSrlCombine(SDNode *N,
3151                                                 DAGCombinerInfo &DCI) const {
3152   auto *RHS = dyn_cast<ConstantSDNode>(N->getOperand(1));
3153   if (!RHS)
3154     return SDValue();
3155 
3156   EVT VT = N->getValueType(0);
3157   SDValue LHS = N->getOperand(0);
3158   unsigned ShiftAmt = RHS->getZExtValue();
3159   SelectionDAG &DAG = DCI.DAG;
3160   SDLoc SL(N);
3161 
3162   // fold (srl (and x, c1 << c2), c2) -> (and (srl(x, c2), c1)
3163   // this improves the ability to match BFE patterns in isel.
3164   if (LHS.getOpcode() == ISD::AND) {
3165     if (auto *Mask = dyn_cast<ConstantSDNode>(LHS.getOperand(1))) {
3166       if (Mask->getAPIntValue().isShiftedMask() &&
3167           Mask->getAPIntValue().countTrailingZeros() == ShiftAmt) {
3168         return DAG.getNode(
3169             ISD::AND, SL, VT,
3170             DAG.getNode(ISD::SRL, SL, VT, LHS.getOperand(0), N->getOperand(1)),
3171             DAG.getNode(ISD::SRL, SL, VT, LHS.getOperand(1), N->getOperand(1)));
3172       }
3173     }
3174   }
3175 
3176   if (VT != MVT::i64)
3177     return SDValue();
3178 
3179   if (ShiftAmt < 32)
3180     return SDValue();
3181 
3182   // srl i64:x, C for C >= 32
3183   // =>
3184   //   build_pair (srl hi_32(x), C - 32), 0
3185   SDValue One = DAG.getConstant(1, SL, MVT::i32);
3186   SDValue Zero = DAG.getConstant(0, SL, MVT::i32);
3187 
3188   SDValue VecOp = DAG.getNode(ISD::BITCAST, SL, MVT::v2i32, LHS);
3189   SDValue Hi = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, SL, MVT::i32, VecOp, One);
3190 
3191   SDValue NewConst = DAG.getConstant(ShiftAmt - 32, SL, MVT::i32);
3192   SDValue NewShift = DAG.getNode(ISD::SRL, SL, MVT::i32, Hi, NewConst);
3193 
3194   SDValue BuildPair = DAG.getBuildVector(MVT::v2i32, SL, {NewShift, Zero});
3195 
3196   return DAG.getNode(ISD::BITCAST, SL, MVT::i64, BuildPair);
3197 }
3198 
performTruncateCombine(SDNode * N,DAGCombinerInfo & DCI) const3199 SDValue AMDGPUTargetLowering::performTruncateCombine(
3200   SDNode *N, DAGCombinerInfo &DCI) const {
3201   SDLoc SL(N);
3202   SelectionDAG &DAG = DCI.DAG;
3203   EVT VT = N->getValueType(0);
3204   SDValue Src = N->getOperand(0);
3205 
3206   // vt1 (truncate (bitcast (build_vector vt0:x, ...))) -> vt1 (bitcast vt0:x)
3207   if (Src.getOpcode() == ISD::BITCAST && !VT.isVector()) {
3208     SDValue Vec = Src.getOperand(0);
3209     if (Vec.getOpcode() == ISD::BUILD_VECTOR) {
3210       SDValue Elt0 = Vec.getOperand(0);
3211       EVT EltVT = Elt0.getValueType();
3212       if (VT.getFixedSizeInBits() <= EltVT.getFixedSizeInBits()) {
3213         if (EltVT.isFloatingPoint()) {
3214           Elt0 = DAG.getNode(ISD::BITCAST, SL,
3215                              EltVT.changeTypeToInteger(), Elt0);
3216         }
3217 
3218         return DAG.getNode(ISD::TRUNCATE, SL, VT, Elt0);
3219       }
3220     }
3221   }
3222 
3223   // Equivalent of above for accessing the high element of a vector as an
3224   // integer operation.
3225   // trunc (srl (bitcast (build_vector x, y))), 16 -> trunc (bitcast y)
3226   if (Src.getOpcode() == ISD::SRL && !VT.isVector()) {
3227     if (auto K = isConstOrConstSplat(Src.getOperand(1))) {
3228       if (2 * K->getZExtValue() == Src.getValueType().getScalarSizeInBits()) {
3229         SDValue BV = stripBitcast(Src.getOperand(0));
3230         if (BV.getOpcode() == ISD::BUILD_VECTOR &&
3231             BV.getValueType().getVectorNumElements() == 2) {
3232           SDValue SrcElt = BV.getOperand(1);
3233           EVT SrcEltVT = SrcElt.getValueType();
3234           if (SrcEltVT.isFloatingPoint()) {
3235             SrcElt = DAG.getNode(ISD::BITCAST, SL,
3236                                  SrcEltVT.changeTypeToInteger(), SrcElt);
3237           }
3238 
3239           return DAG.getNode(ISD::TRUNCATE, SL, VT, SrcElt);
3240         }
3241       }
3242     }
3243   }
3244 
3245   // Partially shrink 64-bit shifts to 32-bit if reduced to 16-bit.
3246   //
3247   // i16 (trunc (srl i64:x, K)), K <= 16 ->
3248   //     i16 (trunc (srl (i32 (trunc x), K)))
3249   if (VT.getScalarSizeInBits() < 32) {
3250     EVT SrcVT = Src.getValueType();
3251     if (SrcVT.getScalarSizeInBits() > 32 &&
3252         (Src.getOpcode() == ISD::SRL ||
3253          Src.getOpcode() == ISD::SRA ||
3254          Src.getOpcode() == ISD::SHL)) {
3255       SDValue Amt = Src.getOperand(1);
3256       KnownBits Known = DAG.computeKnownBits(Amt);
3257       unsigned Size = VT.getScalarSizeInBits();
3258       if ((Known.isConstant() && Known.getConstant().ule(Size)) ||
3259           (Known.getBitWidth() - Known.countMinLeadingZeros() <= Log2_32(Size))) {
3260         EVT MidVT = VT.isVector() ?
3261           EVT::getVectorVT(*DAG.getContext(), MVT::i32,
3262                            VT.getVectorNumElements()) : MVT::i32;
3263 
3264         EVT NewShiftVT = getShiftAmountTy(MidVT, DAG.getDataLayout());
3265         SDValue Trunc = DAG.getNode(ISD::TRUNCATE, SL, MidVT,
3266                                     Src.getOperand(0));
3267         DCI.AddToWorklist(Trunc.getNode());
3268 
3269         if (Amt.getValueType() != NewShiftVT) {
3270           Amt = DAG.getZExtOrTrunc(Amt, SL, NewShiftVT);
3271           DCI.AddToWorklist(Amt.getNode());
3272         }
3273 
3274         SDValue ShrunkShift = DAG.getNode(Src.getOpcode(), SL, MidVT,
3275                                           Trunc, Amt);
3276         return DAG.getNode(ISD::TRUNCATE, SL, VT, ShrunkShift);
3277       }
3278     }
3279   }
3280 
3281   return SDValue();
3282 }
3283 
3284 // We need to specifically handle i64 mul here to avoid unnecessary conversion
3285 // instructions. If we only match on the legalized i64 mul expansion,
3286 // SimplifyDemandedBits will be unable to remove them because there will be
3287 // multiple uses due to the separate mul + mulh[su].
getMul24(SelectionDAG & DAG,const SDLoc & SL,SDValue N0,SDValue N1,unsigned Size,bool Signed)3288 static SDValue getMul24(SelectionDAG &DAG, const SDLoc &SL,
3289                         SDValue N0, SDValue N1, unsigned Size, bool Signed) {
3290   if (Size <= 32) {
3291     unsigned MulOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3292     return DAG.getNode(MulOpc, SL, MVT::i32, N0, N1);
3293   }
3294 
3295   unsigned MulLoOpc = Signed ? AMDGPUISD::MUL_I24 : AMDGPUISD::MUL_U24;
3296   unsigned MulHiOpc = Signed ? AMDGPUISD::MULHI_I24 : AMDGPUISD::MULHI_U24;
3297 
3298   SDValue MulLo = DAG.getNode(MulLoOpc, SL, MVT::i32, N0, N1);
3299   SDValue MulHi = DAG.getNode(MulHiOpc, SL, MVT::i32, N0, N1);
3300 
3301   return DAG.getNode(ISD::BUILD_PAIR, SL, MVT::i64, MulLo, MulHi);
3302 }
3303 
performMulCombine(SDNode * N,DAGCombinerInfo & DCI) const3304 SDValue AMDGPUTargetLowering::performMulCombine(SDNode *N,
3305                                                 DAGCombinerInfo &DCI) const {
3306   EVT VT = N->getValueType(0);
3307 
3308   // Don't generate 24-bit multiplies on values that are in SGPRs, since
3309   // we only have a 32-bit scalar multiply (avoid values being moved to VGPRs
3310   // unnecessarily). isDivergent() is used as an approximation of whether the
3311   // value is in an SGPR.
3312   if (!N->isDivergent())
3313     return SDValue();
3314 
3315   unsigned Size = VT.getSizeInBits();
3316   if (VT.isVector() || Size > 64)
3317     return SDValue();
3318 
3319   // There are i16 integer mul/mad.
3320   if (Subtarget->has16BitInsts() && VT.getScalarType().bitsLE(MVT::i16))
3321     return SDValue();
3322 
3323   SelectionDAG &DAG = DCI.DAG;
3324   SDLoc DL(N);
3325 
3326   SDValue N0 = N->getOperand(0);
3327   SDValue N1 = N->getOperand(1);
3328 
3329   // SimplifyDemandedBits has the annoying habit of turning useful zero_extends
3330   // in the source into any_extends if the result of the mul is truncated. Since
3331   // we can assume the high bits are whatever we want, use the underlying value
3332   // to avoid the unknown high bits from interfering.
3333   if (N0.getOpcode() == ISD::ANY_EXTEND)
3334     N0 = N0.getOperand(0);
3335 
3336   if (N1.getOpcode() == ISD::ANY_EXTEND)
3337     N1 = N1.getOperand(0);
3338 
3339   SDValue Mul;
3340 
3341   if (Subtarget->hasMulU24() && isU24(N0, DAG) && isU24(N1, DAG)) {
3342     N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3343     N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3344     Mul = getMul24(DAG, DL, N0, N1, Size, false);
3345   } else if (Subtarget->hasMulI24() && isI24(N0, DAG) && isI24(N1, DAG)) {
3346     N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3347     N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3348     Mul = getMul24(DAG, DL, N0, N1, Size, true);
3349   } else {
3350     return SDValue();
3351   }
3352 
3353   // We need to use sext even for MUL_U24, because MUL_U24 is used
3354   // for signed multiply of 8 and 16-bit types.
3355   return DAG.getSExtOrTrunc(Mul, DL, VT);
3356 }
3357 
performMulhsCombine(SDNode * N,DAGCombinerInfo & DCI) const3358 SDValue AMDGPUTargetLowering::performMulhsCombine(SDNode *N,
3359                                                   DAGCombinerInfo &DCI) const {
3360   EVT VT = N->getValueType(0);
3361 
3362   if (!Subtarget->hasMulI24() || VT.isVector())
3363     return SDValue();
3364 
3365   SelectionDAG &DAG = DCI.DAG;
3366   SDLoc DL(N);
3367 
3368   SDValue N0 = N->getOperand(0);
3369   SDValue N1 = N->getOperand(1);
3370 
3371   if (!isI24(N0, DAG) || !isI24(N1, DAG))
3372     return SDValue();
3373 
3374   N0 = DAG.getSExtOrTrunc(N0, DL, MVT::i32);
3375   N1 = DAG.getSExtOrTrunc(N1, DL, MVT::i32);
3376 
3377   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_I24, DL, MVT::i32, N0, N1);
3378   DCI.AddToWorklist(Mulhi.getNode());
3379   return DAG.getSExtOrTrunc(Mulhi, DL, VT);
3380 }
3381 
performMulhuCombine(SDNode * N,DAGCombinerInfo & DCI) const3382 SDValue AMDGPUTargetLowering::performMulhuCombine(SDNode *N,
3383                                                   DAGCombinerInfo &DCI) const {
3384   EVT VT = N->getValueType(0);
3385 
3386   if (!Subtarget->hasMulU24() || VT.isVector() || VT.getSizeInBits() > 32)
3387     return SDValue();
3388 
3389   SelectionDAG &DAG = DCI.DAG;
3390   SDLoc DL(N);
3391 
3392   SDValue N0 = N->getOperand(0);
3393   SDValue N1 = N->getOperand(1);
3394 
3395   if (!isU24(N0, DAG) || !isU24(N1, DAG))
3396     return SDValue();
3397 
3398   N0 = DAG.getZExtOrTrunc(N0, DL, MVT::i32);
3399   N1 = DAG.getZExtOrTrunc(N1, DL, MVT::i32);
3400 
3401   SDValue Mulhi = DAG.getNode(AMDGPUISD::MULHI_U24, DL, MVT::i32, N0, N1);
3402   DCI.AddToWorklist(Mulhi.getNode());
3403   return DAG.getZExtOrTrunc(Mulhi, DL, VT);
3404 }
3405 
isNegativeOne(SDValue Val)3406 static bool isNegativeOne(SDValue Val) {
3407   if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Val))
3408     return C->isAllOnesValue();
3409   return false;
3410 }
3411 
getFFBX_U32(SelectionDAG & DAG,SDValue Op,const SDLoc & DL,unsigned Opc) const3412 SDValue AMDGPUTargetLowering::getFFBX_U32(SelectionDAG &DAG,
3413                                           SDValue Op,
3414                                           const SDLoc &DL,
3415                                           unsigned Opc) const {
3416   EVT VT = Op.getValueType();
3417   EVT LegalVT = getTypeToTransformTo(*DAG.getContext(), VT);
3418   if (LegalVT != MVT::i32 && (Subtarget->has16BitInsts() &&
3419                               LegalVT != MVT::i16))
3420     return SDValue();
3421 
3422   if (VT != MVT::i32)
3423     Op = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, Op);
3424 
3425   SDValue FFBX = DAG.getNode(Opc, DL, MVT::i32, Op);
3426   if (VT != MVT::i32)
3427     FFBX = DAG.getNode(ISD::TRUNCATE, DL, VT, FFBX);
3428 
3429   return FFBX;
3430 }
3431 
3432 // The native instructions return -1 on 0 input. Optimize out a select that
3433 // produces -1 on 0.
3434 //
3435 // TODO: If zero is not undef, we could also do this if the output is compared
3436 // against the bitwidth.
3437 //
3438 // TODO: Should probably combine against FFBH_U32 instead of ctlz directly.
performCtlz_CttzCombine(const SDLoc & SL,SDValue Cond,SDValue LHS,SDValue RHS,DAGCombinerInfo & DCI) const3439 SDValue AMDGPUTargetLowering::performCtlz_CttzCombine(const SDLoc &SL, SDValue Cond,
3440                                                  SDValue LHS, SDValue RHS,
3441                                                  DAGCombinerInfo &DCI) const {
3442   ConstantSDNode *CmpRhs = dyn_cast<ConstantSDNode>(Cond.getOperand(1));
3443   if (!CmpRhs || !CmpRhs->isNullValue())
3444     return SDValue();
3445 
3446   SelectionDAG &DAG = DCI.DAG;
3447   ISD::CondCode CCOpcode = cast<CondCodeSDNode>(Cond.getOperand(2))->get();
3448   SDValue CmpLHS = Cond.getOperand(0);
3449 
3450   // select (setcc x, 0, eq), -1, (ctlz_zero_undef x) -> ffbh_u32 x
3451   // select (setcc x, 0, eq), -1, (cttz_zero_undef x) -> ffbl_u32 x
3452   if (CCOpcode == ISD::SETEQ &&
3453       (isCtlzOpc(RHS.getOpcode()) || isCttzOpc(RHS.getOpcode())) &&
3454       RHS.getOperand(0) == CmpLHS && isNegativeOne(LHS)) {
3455     unsigned Opc =
3456         isCttzOpc(RHS.getOpcode()) ? AMDGPUISD::FFBL_B32 : AMDGPUISD::FFBH_U32;
3457     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3458   }
3459 
3460   // select (setcc x, 0, ne), (ctlz_zero_undef x), -1 -> ffbh_u32 x
3461   // select (setcc x, 0, ne), (cttz_zero_undef x), -1 -> ffbl_u32 x
3462   if (CCOpcode == ISD::SETNE &&
3463       (isCtlzOpc(LHS.getOpcode()) || isCttzOpc(LHS.getOpcode())) &&
3464       LHS.getOperand(0) == CmpLHS && isNegativeOne(RHS)) {
3465     unsigned Opc =
3466         isCttzOpc(LHS.getOpcode()) ? AMDGPUISD::FFBL_B32 : AMDGPUISD::FFBH_U32;
3467 
3468     return getFFBX_U32(DAG, CmpLHS, SL, Opc);
3469   }
3470 
3471   return SDValue();
3472 }
3473 
distributeOpThroughSelect(TargetLowering::DAGCombinerInfo & DCI,unsigned Op,const SDLoc & SL,SDValue Cond,SDValue N1,SDValue N2)3474 static SDValue distributeOpThroughSelect(TargetLowering::DAGCombinerInfo &DCI,
3475                                          unsigned Op,
3476                                          const SDLoc &SL,
3477                                          SDValue Cond,
3478                                          SDValue N1,
3479                                          SDValue N2) {
3480   SelectionDAG &DAG = DCI.DAG;
3481   EVT VT = N1.getValueType();
3482 
3483   SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT, Cond,
3484                                   N1.getOperand(0), N2.getOperand(0));
3485   DCI.AddToWorklist(NewSelect.getNode());
3486   return DAG.getNode(Op, SL, VT, NewSelect);
3487 }
3488 
3489 // Pull a free FP operation out of a select so it may fold into uses.
3490 //
3491 // select c, (fneg x), (fneg y) -> fneg (select c, x, y)
3492 // select c, (fneg x), k -> fneg (select c, x, (fneg k))
3493 //
3494 // select c, (fabs x), (fabs y) -> fabs (select c, x, y)
3495 // select c, (fabs x), +k -> fabs (select c, x, k)
foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo & DCI,SDValue N)3496 static SDValue foldFreeOpFromSelect(TargetLowering::DAGCombinerInfo &DCI,
3497                                     SDValue N) {
3498   SelectionDAG &DAG = DCI.DAG;
3499   SDValue Cond = N.getOperand(0);
3500   SDValue LHS = N.getOperand(1);
3501   SDValue RHS = N.getOperand(2);
3502 
3503   EVT VT = N.getValueType();
3504   if ((LHS.getOpcode() == ISD::FABS && RHS.getOpcode() == ISD::FABS) ||
3505       (LHS.getOpcode() == ISD::FNEG && RHS.getOpcode() == ISD::FNEG)) {
3506     return distributeOpThroughSelect(DCI, LHS.getOpcode(),
3507                                      SDLoc(N), Cond, LHS, RHS);
3508   }
3509 
3510   bool Inv = false;
3511   if (RHS.getOpcode() == ISD::FABS || RHS.getOpcode() == ISD::FNEG) {
3512     std::swap(LHS, RHS);
3513     Inv = true;
3514   }
3515 
3516   // TODO: Support vector constants.
3517   ConstantFPSDNode *CRHS = dyn_cast<ConstantFPSDNode>(RHS);
3518   if ((LHS.getOpcode() == ISD::FNEG || LHS.getOpcode() == ISD::FABS) && CRHS) {
3519     SDLoc SL(N);
3520     // If one side is an fneg/fabs and the other is a constant, we can push the
3521     // fneg/fabs down. If it's an fabs, the constant needs to be non-negative.
3522     SDValue NewLHS = LHS.getOperand(0);
3523     SDValue NewRHS = RHS;
3524 
3525     // Careful: if the neg can be folded up, don't try to pull it back down.
3526     bool ShouldFoldNeg = true;
3527 
3528     if (NewLHS.hasOneUse()) {
3529       unsigned Opc = NewLHS.getOpcode();
3530       if (LHS.getOpcode() == ISD::FNEG && fnegFoldsIntoOp(Opc))
3531         ShouldFoldNeg = false;
3532       if (LHS.getOpcode() == ISD::FABS && Opc == ISD::FMUL)
3533         ShouldFoldNeg = false;
3534     }
3535 
3536     if (ShouldFoldNeg) {
3537       if (LHS.getOpcode() == ISD::FNEG)
3538         NewRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3539       else if (CRHS->isNegative())
3540         return SDValue();
3541 
3542       if (Inv)
3543         std::swap(NewLHS, NewRHS);
3544 
3545       SDValue NewSelect = DAG.getNode(ISD::SELECT, SL, VT,
3546                                       Cond, NewLHS, NewRHS);
3547       DCI.AddToWorklist(NewSelect.getNode());
3548       return DAG.getNode(LHS.getOpcode(), SL, VT, NewSelect);
3549     }
3550   }
3551 
3552   return SDValue();
3553 }
3554 
3555 
performSelectCombine(SDNode * N,DAGCombinerInfo & DCI) const3556 SDValue AMDGPUTargetLowering::performSelectCombine(SDNode *N,
3557                                                    DAGCombinerInfo &DCI) const {
3558   if (SDValue Folded = foldFreeOpFromSelect(DCI, SDValue(N, 0)))
3559     return Folded;
3560 
3561   SDValue Cond = N->getOperand(0);
3562   if (Cond.getOpcode() != ISD::SETCC)
3563     return SDValue();
3564 
3565   EVT VT = N->getValueType(0);
3566   SDValue LHS = Cond.getOperand(0);
3567   SDValue RHS = Cond.getOperand(1);
3568   SDValue CC = Cond.getOperand(2);
3569 
3570   SDValue True = N->getOperand(1);
3571   SDValue False = N->getOperand(2);
3572 
3573   if (Cond.hasOneUse()) { // TODO: Look for multiple select uses.
3574     SelectionDAG &DAG = DCI.DAG;
3575     if (DAG.isConstantValueOfAnyType(True) &&
3576         !DAG.isConstantValueOfAnyType(False)) {
3577       // Swap cmp + select pair to move constant to false input.
3578       // This will allow using VOPC cndmasks more often.
3579       // select (setcc x, y), k, x -> select (setccinv x, y), x, k
3580 
3581       SDLoc SL(N);
3582       ISD::CondCode NewCC =
3583           getSetCCInverse(cast<CondCodeSDNode>(CC)->get(), LHS.getValueType());
3584 
3585       SDValue NewCond = DAG.getSetCC(SL, Cond.getValueType(), LHS, RHS, NewCC);
3586       return DAG.getNode(ISD::SELECT, SL, VT, NewCond, False, True);
3587     }
3588 
3589     if (VT == MVT::f32 && Subtarget->hasFminFmaxLegacy()) {
3590       SDValue MinMax
3591         = combineFMinMaxLegacy(SDLoc(N), VT, LHS, RHS, True, False, CC, DCI);
3592       // Revisit this node so we can catch min3/max3/med3 patterns.
3593       //DCI.AddToWorklist(MinMax.getNode());
3594       return MinMax;
3595     }
3596   }
3597 
3598   // There's no reason to not do this if the condition has other uses.
3599   return performCtlz_CttzCombine(SDLoc(N), Cond, True, False, DCI);
3600 }
3601 
isInv2Pi(const APFloat & APF)3602 static bool isInv2Pi(const APFloat &APF) {
3603   static const APFloat KF16(APFloat::IEEEhalf(), APInt(16, 0x3118));
3604   static const APFloat KF32(APFloat::IEEEsingle(), APInt(32, 0x3e22f983));
3605   static const APFloat KF64(APFloat::IEEEdouble(), APInt(64, 0x3fc45f306dc9c882));
3606 
3607   return APF.bitwiseIsEqual(KF16) ||
3608          APF.bitwiseIsEqual(KF32) ||
3609          APF.bitwiseIsEqual(KF64);
3610 }
3611 
3612 // 0 and 1.0 / (0.5 * pi) do not have inline immmediates, so there is an
3613 // additional cost to negate them.
isConstantCostlierToNegate(SDValue N) const3614 bool AMDGPUTargetLowering::isConstantCostlierToNegate(SDValue N) const {
3615   if (const ConstantFPSDNode *C = isConstOrConstSplatFP(N)) {
3616     if (C->isZero() && !C->isNegative())
3617       return true;
3618 
3619     if (Subtarget->hasInv2PiInlineImm() && isInv2Pi(C->getValueAPF()))
3620       return true;
3621   }
3622 
3623   return false;
3624 }
3625 
inverseMinMax(unsigned Opc)3626 static unsigned inverseMinMax(unsigned Opc) {
3627   switch (Opc) {
3628   case ISD::FMAXNUM:
3629     return ISD::FMINNUM;
3630   case ISD::FMINNUM:
3631     return ISD::FMAXNUM;
3632   case ISD::FMAXNUM_IEEE:
3633     return ISD::FMINNUM_IEEE;
3634   case ISD::FMINNUM_IEEE:
3635     return ISD::FMAXNUM_IEEE;
3636   case AMDGPUISD::FMAX_LEGACY:
3637     return AMDGPUISD::FMIN_LEGACY;
3638   case AMDGPUISD::FMIN_LEGACY:
3639     return  AMDGPUISD::FMAX_LEGACY;
3640   default:
3641     llvm_unreachable("invalid min/max opcode");
3642   }
3643 }
3644 
performFNegCombine(SDNode * N,DAGCombinerInfo & DCI) const3645 SDValue AMDGPUTargetLowering::performFNegCombine(SDNode *N,
3646                                                  DAGCombinerInfo &DCI) const {
3647   SelectionDAG &DAG = DCI.DAG;
3648   SDValue N0 = N->getOperand(0);
3649   EVT VT = N->getValueType(0);
3650 
3651   unsigned Opc = N0.getOpcode();
3652 
3653   // If the input has multiple uses and we can either fold the negate down, or
3654   // the other uses cannot, give up. This both prevents unprofitable
3655   // transformations and infinite loops: we won't repeatedly try to fold around
3656   // a negate that has no 'good' form.
3657   if (N0.hasOneUse()) {
3658     // This may be able to fold into the source, but at a code size cost. Don't
3659     // fold if the fold into the user is free.
3660     if (allUsesHaveSourceMods(N, 0))
3661       return SDValue();
3662   } else {
3663     if (fnegFoldsIntoOp(Opc) &&
3664         (allUsesHaveSourceMods(N) || !allUsesHaveSourceMods(N0.getNode())))
3665       return SDValue();
3666   }
3667 
3668   SDLoc SL(N);
3669   switch (Opc) {
3670   case ISD::FADD: {
3671     if (!mayIgnoreSignedZero(N0))
3672       return SDValue();
3673 
3674     // (fneg (fadd x, y)) -> (fadd (fneg x), (fneg y))
3675     SDValue LHS = N0.getOperand(0);
3676     SDValue RHS = N0.getOperand(1);
3677 
3678     if (LHS.getOpcode() != ISD::FNEG)
3679       LHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3680     else
3681       LHS = LHS.getOperand(0);
3682 
3683     if (RHS.getOpcode() != ISD::FNEG)
3684       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3685     else
3686       RHS = RHS.getOperand(0);
3687 
3688     SDValue Res = DAG.getNode(ISD::FADD, SL, VT, LHS, RHS, N0->getFlags());
3689     if (Res.getOpcode() != ISD::FADD)
3690       return SDValue(); // Op got folded away.
3691     if (!N0.hasOneUse())
3692       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3693     return Res;
3694   }
3695   case ISD::FMUL:
3696   case AMDGPUISD::FMUL_LEGACY: {
3697     // (fneg (fmul x, y)) -> (fmul x, (fneg y))
3698     // (fneg (fmul_legacy x, y)) -> (fmul_legacy x, (fneg y))
3699     SDValue LHS = N0.getOperand(0);
3700     SDValue RHS = N0.getOperand(1);
3701 
3702     if (LHS.getOpcode() == ISD::FNEG)
3703       LHS = LHS.getOperand(0);
3704     else if (RHS.getOpcode() == ISD::FNEG)
3705       RHS = RHS.getOperand(0);
3706     else
3707       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3708 
3709     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, RHS, N0->getFlags());
3710     if (Res.getOpcode() != Opc)
3711       return SDValue(); // Op got folded away.
3712     if (!N0.hasOneUse())
3713       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3714     return Res;
3715   }
3716   case ISD::FMA:
3717   case ISD::FMAD: {
3718     // TODO: handle llvm.amdgcn.fma.legacy
3719     if (!mayIgnoreSignedZero(N0))
3720       return SDValue();
3721 
3722     // (fneg (fma x, y, z)) -> (fma x, (fneg y), (fneg z))
3723     SDValue LHS = N0.getOperand(0);
3724     SDValue MHS = N0.getOperand(1);
3725     SDValue RHS = N0.getOperand(2);
3726 
3727     if (LHS.getOpcode() == ISD::FNEG)
3728       LHS = LHS.getOperand(0);
3729     else if (MHS.getOpcode() == ISD::FNEG)
3730       MHS = MHS.getOperand(0);
3731     else
3732       MHS = DAG.getNode(ISD::FNEG, SL, VT, MHS);
3733 
3734     if (RHS.getOpcode() != ISD::FNEG)
3735       RHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3736     else
3737       RHS = RHS.getOperand(0);
3738 
3739     SDValue Res = DAG.getNode(Opc, SL, VT, LHS, MHS, RHS);
3740     if (Res.getOpcode() != Opc)
3741       return SDValue(); // Op got folded away.
3742     if (!N0.hasOneUse())
3743       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3744     return Res;
3745   }
3746   case ISD::FMAXNUM:
3747   case ISD::FMINNUM:
3748   case ISD::FMAXNUM_IEEE:
3749   case ISD::FMINNUM_IEEE:
3750   case AMDGPUISD::FMAX_LEGACY:
3751   case AMDGPUISD::FMIN_LEGACY: {
3752     // fneg (fmaxnum x, y) -> fminnum (fneg x), (fneg y)
3753     // fneg (fminnum x, y) -> fmaxnum (fneg x), (fneg y)
3754     // fneg (fmax_legacy x, y) -> fmin_legacy (fneg x), (fneg y)
3755     // fneg (fmin_legacy x, y) -> fmax_legacy (fneg x), (fneg y)
3756 
3757     SDValue LHS = N0.getOperand(0);
3758     SDValue RHS = N0.getOperand(1);
3759 
3760     // 0 doesn't have a negated inline immediate.
3761     // TODO: This constant check should be generalized to other operations.
3762     if (isConstantCostlierToNegate(RHS))
3763       return SDValue();
3764 
3765     SDValue NegLHS = DAG.getNode(ISD::FNEG, SL, VT, LHS);
3766     SDValue NegRHS = DAG.getNode(ISD::FNEG, SL, VT, RHS);
3767     unsigned Opposite = inverseMinMax(Opc);
3768 
3769     SDValue Res = DAG.getNode(Opposite, SL, VT, NegLHS, NegRHS, N0->getFlags());
3770     if (Res.getOpcode() != Opposite)
3771       return SDValue(); // Op got folded away.
3772     if (!N0.hasOneUse())
3773       DAG.ReplaceAllUsesWith(N0, DAG.getNode(ISD::FNEG, SL, VT, Res));
3774     return Res;
3775   }
3776   case AMDGPUISD::FMED3: {
3777     SDValue Ops[3];
3778     for (unsigned I = 0; I < 3; ++I)
3779       Ops[I] = DAG.getNode(ISD::FNEG, SL, VT, N0->getOperand(I), N0->getFlags());
3780 
3781     SDValue Res = DAG.getNode(AMDGPUISD::FMED3, SL, VT, Ops, N0->getFlags());
3782     if (Res.getOpcode() != AMDGPUISD::FMED3)
3783       return SDValue(); // Op got folded away.
3784 
3785     if (!N0.hasOneUse()) {
3786       SDValue Neg = DAG.getNode(ISD::FNEG, SL, VT, Res);
3787       DAG.ReplaceAllUsesWith(N0, Neg);
3788 
3789       for (SDNode *U : Neg->uses())
3790         DCI.AddToWorklist(U);
3791     }
3792 
3793     return Res;
3794   }
3795   case ISD::FP_EXTEND:
3796   case ISD::FTRUNC:
3797   case ISD::FRINT:
3798   case ISD::FNEARBYINT: // XXX - Should fround be handled?
3799   case ISD::FSIN:
3800   case ISD::FCANONICALIZE:
3801   case AMDGPUISD::RCP:
3802   case AMDGPUISD::RCP_LEGACY:
3803   case AMDGPUISD::RCP_IFLAG:
3804   case AMDGPUISD::SIN_HW: {
3805     SDValue CvtSrc = N0.getOperand(0);
3806     if (CvtSrc.getOpcode() == ISD::FNEG) {
3807       // (fneg (fp_extend (fneg x))) -> (fp_extend x)
3808       // (fneg (rcp (fneg x))) -> (rcp x)
3809       return DAG.getNode(Opc, SL, VT, CvtSrc.getOperand(0));
3810     }
3811 
3812     if (!N0.hasOneUse())
3813       return SDValue();
3814 
3815     // (fneg (fp_extend x)) -> (fp_extend (fneg x))
3816     // (fneg (rcp x)) -> (rcp (fneg x))
3817     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3818     return DAG.getNode(Opc, SL, VT, Neg, N0->getFlags());
3819   }
3820   case ISD::FP_ROUND: {
3821     SDValue CvtSrc = N0.getOperand(0);
3822 
3823     if (CvtSrc.getOpcode() == ISD::FNEG) {
3824       // (fneg (fp_round (fneg x))) -> (fp_round x)
3825       return DAG.getNode(ISD::FP_ROUND, SL, VT,
3826                          CvtSrc.getOperand(0), N0.getOperand(1));
3827     }
3828 
3829     if (!N0.hasOneUse())
3830       return SDValue();
3831 
3832     // (fneg (fp_round x)) -> (fp_round (fneg x))
3833     SDValue Neg = DAG.getNode(ISD::FNEG, SL, CvtSrc.getValueType(), CvtSrc);
3834     return DAG.getNode(ISD::FP_ROUND, SL, VT, Neg, N0.getOperand(1));
3835   }
3836   case ISD::FP16_TO_FP: {
3837     // v_cvt_f32_f16 supports source modifiers on pre-VI targets without legal
3838     // f16, but legalization of f16 fneg ends up pulling it out of the source.
3839     // Put the fneg back as a legal source operation that can be matched later.
3840     SDLoc SL(N);
3841 
3842     SDValue Src = N0.getOperand(0);
3843     EVT SrcVT = Src.getValueType();
3844 
3845     // fneg (fp16_to_fp x) -> fp16_to_fp (xor x, 0x8000)
3846     SDValue IntFNeg = DAG.getNode(ISD::XOR, SL, SrcVT, Src,
3847                                   DAG.getConstant(0x8000, SL, SrcVT));
3848     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFNeg);
3849   }
3850   default:
3851     return SDValue();
3852   }
3853 }
3854 
performFAbsCombine(SDNode * N,DAGCombinerInfo & DCI) const3855 SDValue AMDGPUTargetLowering::performFAbsCombine(SDNode *N,
3856                                                  DAGCombinerInfo &DCI) const {
3857   SelectionDAG &DAG = DCI.DAG;
3858   SDValue N0 = N->getOperand(0);
3859 
3860   if (!N0.hasOneUse())
3861     return SDValue();
3862 
3863   switch (N0.getOpcode()) {
3864   case ISD::FP16_TO_FP: {
3865     assert(!Subtarget->has16BitInsts() && "should only see if f16 is illegal");
3866     SDLoc SL(N);
3867     SDValue Src = N0.getOperand(0);
3868     EVT SrcVT = Src.getValueType();
3869 
3870     // fabs (fp16_to_fp x) -> fp16_to_fp (and x, 0x7fff)
3871     SDValue IntFAbs = DAG.getNode(ISD::AND, SL, SrcVT, Src,
3872                                   DAG.getConstant(0x7fff, SL, SrcVT));
3873     return DAG.getNode(ISD::FP16_TO_FP, SL, N->getValueType(0), IntFAbs);
3874   }
3875   default:
3876     return SDValue();
3877   }
3878 }
3879 
performRcpCombine(SDNode * N,DAGCombinerInfo & DCI) const3880 SDValue AMDGPUTargetLowering::performRcpCombine(SDNode *N,
3881                                                 DAGCombinerInfo &DCI) const {
3882   const auto *CFP = dyn_cast<ConstantFPSDNode>(N->getOperand(0));
3883   if (!CFP)
3884     return SDValue();
3885 
3886   // XXX - Should this flush denormals?
3887   const APFloat &Val = CFP->getValueAPF();
3888   APFloat One(Val.getSemantics(), "1.0");
3889   return DCI.DAG.getConstantFP(One / Val, SDLoc(N), N->getValueType(0));
3890 }
3891 
PerformDAGCombine(SDNode * N,DAGCombinerInfo & DCI) const3892 SDValue AMDGPUTargetLowering::PerformDAGCombine(SDNode *N,
3893                                                 DAGCombinerInfo &DCI) const {
3894   SelectionDAG &DAG = DCI.DAG;
3895   SDLoc DL(N);
3896 
3897   switch(N->getOpcode()) {
3898   default:
3899     break;
3900   case ISD::BITCAST: {
3901     EVT DestVT = N->getValueType(0);
3902 
3903     // Push casts through vector builds. This helps avoid emitting a large
3904     // number of copies when materializing floating point vector constants.
3905     //
3906     // vNt1 bitcast (vNt0 (build_vector t0:x, t0:y)) =>
3907     //   vnt1 = build_vector (t1 (bitcast t0:x)), (t1 (bitcast t0:y))
3908     if (DestVT.isVector()) {
3909       SDValue Src = N->getOperand(0);
3910       if (Src.getOpcode() == ISD::BUILD_VECTOR) {
3911         EVT SrcVT = Src.getValueType();
3912         unsigned NElts = DestVT.getVectorNumElements();
3913 
3914         if (SrcVT.getVectorNumElements() == NElts) {
3915           EVT DestEltVT = DestVT.getVectorElementType();
3916 
3917           SmallVector<SDValue, 8> CastedElts;
3918           SDLoc SL(N);
3919           for (unsigned I = 0, E = SrcVT.getVectorNumElements(); I != E; ++I) {
3920             SDValue Elt = Src.getOperand(I);
3921             CastedElts.push_back(DAG.getNode(ISD::BITCAST, DL, DestEltVT, Elt));
3922           }
3923 
3924           return DAG.getBuildVector(DestVT, SL, CastedElts);
3925         }
3926       }
3927     }
3928 
3929     if (DestVT.getSizeInBits() != 64 || !DestVT.isVector())
3930       break;
3931 
3932     // Fold bitcasts of constants.
3933     //
3934     // v2i32 (bitcast i64:k) -> build_vector lo_32(k), hi_32(k)
3935     // TODO: Generalize and move to DAGCombiner
3936     SDValue Src = N->getOperand(0);
3937     if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Src)) {
3938       SDLoc SL(N);
3939       uint64_t CVal = C->getZExtValue();
3940       SDValue BV = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3941                                DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3942                                DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3943       return DAG.getNode(ISD::BITCAST, SL, DestVT, BV);
3944     }
3945 
3946     if (ConstantFPSDNode *C = dyn_cast<ConstantFPSDNode>(Src)) {
3947       const APInt &Val = C->getValueAPF().bitcastToAPInt();
3948       SDLoc SL(N);
3949       uint64_t CVal = Val.getZExtValue();
3950       SDValue Vec = DAG.getNode(ISD::BUILD_VECTOR, SL, MVT::v2i32,
3951                                 DAG.getConstant(Lo_32(CVal), SL, MVT::i32),
3952                                 DAG.getConstant(Hi_32(CVal), SL, MVT::i32));
3953 
3954       return DAG.getNode(ISD::BITCAST, SL, DestVT, Vec);
3955     }
3956 
3957     break;
3958   }
3959   case ISD::SHL: {
3960     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3961       break;
3962 
3963     return performShlCombine(N, DCI);
3964   }
3965   case ISD::SRL: {
3966     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3967       break;
3968 
3969     return performSrlCombine(N, DCI);
3970   }
3971   case ISD::SRA: {
3972     if (DCI.getDAGCombineLevel() < AfterLegalizeDAG)
3973       break;
3974 
3975     return performSraCombine(N, DCI);
3976   }
3977   case ISD::TRUNCATE:
3978     return performTruncateCombine(N, DCI);
3979   case ISD::MUL:
3980     return performMulCombine(N, DCI);
3981   case ISD::MULHS:
3982     return performMulhsCombine(N, DCI);
3983   case ISD::MULHU:
3984     return performMulhuCombine(N, DCI);
3985   case AMDGPUISD::MUL_I24:
3986   case AMDGPUISD::MUL_U24:
3987   case AMDGPUISD::MULHI_I24:
3988   case AMDGPUISD::MULHI_U24:
3989     return simplifyMul24(N, DCI);
3990   case ISD::SELECT:
3991     return performSelectCombine(N, DCI);
3992   case ISD::FNEG:
3993     return performFNegCombine(N, DCI);
3994   case ISD::FABS:
3995     return performFAbsCombine(N, DCI);
3996   case AMDGPUISD::BFE_I32:
3997   case AMDGPUISD::BFE_U32: {
3998     assert(!N->getValueType(0).isVector() &&
3999            "Vector handling of BFE not implemented");
4000     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(N->getOperand(2));
4001     if (!Width)
4002       break;
4003 
4004     uint32_t WidthVal = Width->getZExtValue() & 0x1f;
4005     if (WidthVal == 0)
4006       return DAG.getConstant(0, DL, MVT::i32);
4007 
4008     ConstantSDNode *Offset = dyn_cast<ConstantSDNode>(N->getOperand(1));
4009     if (!Offset)
4010       break;
4011 
4012     SDValue BitsFrom = N->getOperand(0);
4013     uint32_t OffsetVal = Offset->getZExtValue() & 0x1f;
4014 
4015     bool Signed = N->getOpcode() == AMDGPUISD::BFE_I32;
4016 
4017     if (OffsetVal == 0) {
4018       // This is already sign / zero extended, so try to fold away extra BFEs.
4019       unsigned SignBits =  Signed ? (32 - WidthVal + 1) : (32 - WidthVal);
4020 
4021       unsigned OpSignBits = DAG.ComputeNumSignBits(BitsFrom);
4022       if (OpSignBits >= SignBits)
4023         return BitsFrom;
4024 
4025       EVT SmallVT = EVT::getIntegerVT(*DAG.getContext(), WidthVal);
4026       if (Signed) {
4027         // This is a sign_extend_inreg. Replace it to take advantage of existing
4028         // DAG Combines. If not eliminated, we will match back to BFE during
4029         // selection.
4030 
4031         // TODO: The sext_inreg of extended types ends, although we can could
4032         // handle them in a single BFE.
4033         return DAG.getNode(ISD::SIGN_EXTEND_INREG, DL, MVT::i32, BitsFrom,
4034                            DAG.getValueType(SmallVT));
4035       }
4036 
4037       return DAG.getZeroExtendInReg(BitsFrom, DL, SmallVT);
4038     }
4039 
4040     if (ConstantSDNode *CVal = dyn_cast<ConstantSDNode>(BitsFrom)) {
4041       if (Signed) {
4042         return constantFoldBFE<int32_t>(DAG,
4043                                         CVal->getSExtValue(),
4044                                         OffsetVal,
4045                                         WidthVal,
4046                                         DL);
4047       }
4048 
4049       return constantFoldBFE<uint32_t>(DAG,
4050                                        CVal->getZExtValue(),
4051                                        OffsetVal,
4052                                        WidthVal,
4053                                        DL);
4054     }
4055 
4056     if ((OffsetVal + WidthVal) >= 32 &&
4057         !(Subtarget->hasSDWA() && OffsetVal == 16 && WidthVal == 16)) {
4058       SDValue ShiftVal = DAG.getConstant(OffsetVal, DL, MVT::i32);
4059       return DAG.getNode(Signed ? ISD::SRA : ISD::SRL, DL, MVT::i32,
4060                          BitsFrom, ShiftVal);
4061     }
4062 
4063     if (BitsFrom.hasOneUse()) {
4064       APInt Demanded = APInt::getBitsSet(32,
4065                                          OffsetVal,
4066                                          OffsetVal + WidthVal);
4067 
4068       KnownBits Known;
4069       TargetLowering::TargetLoweringOpt TLO(DAG, !DCI.isBeforeLegalize(),
4070                                             !DCI.isBeforeLegalizeOps());
4071       const TargetLowering &TLI = DAG.getTargetLoweringInfo();
4072       if (TLI.ShrinkDemandedConstant(BitsFrom, Demanded, TLO) ||
4073           TLI.SimplifyDemandedBits(BitsFrom, Demanded, Known, TLO)) {
4074         DCI.CommitTargetLoweringOpt(TLO);
4075       }
4076     }
4077 
4078     break;
4079   }
4080   case ISD::LOAD:
4081     return performLoadCombine(N, DCI);
4082   case ISD::STORE:
4083     return performStoreCombine(N, DCI);
4084   case AMDGPUISD::RCP:
4085   case AMDGPUISD::RCP_IFLAG:
4086     return performRcpCombine(N, DCI);
4087   case ISD::AssertZext:
4088   case ISD::AssertSext:
4089     return performAssertSZExtCombine(N, DCI);
4090   case ISD::INTRINSIC_WO_CHAIN:
4091     return performIntrinsicWOChainCombine(N, DCI);
4092   }
4093   return SDValue();
4094 }
4095 
4096 //===----------------------------------------------------------------------===//
4097 // Helper functions
4098 //===----------------------------------------------------------------------===//
4099 
CreateLiveInRegister(SelectionDAG & DAG,const TargetRegisterClass * RC,Register Reg,EVT VT,const SDLoc & SL,bool RawReg) const4100 SDValue AMDGPUTargetLowering::CreateLiveInRegister(SelectionDAG &DAG,
4101                                                    const TargetRegisterClass *RC,
4102                                                    Register Reg, EVT VT,
4103                                                    const SDLoc &SL,
4104                                                    bool RawReg) const {
4105   MachineFunction &MF = DAG.getMachineFunction();
4106   MachineRegisterInfo &MRI = MF.getRegInfo();
4107   Register VReg;
4108 
4109   if (!MRI.isLiveIn(Reg)) {
4110     VReg = MRI.createVirtualRegister(RC);
4111     MRI.addLiveIn(Reg, VReg);
4112   } else {
4113     VReg = MRI.getLiveInVirtReg(Reg);
4114   }
4115 
4116   if (RawReg)
4117     return DAG.getRegister(VReg, VT);
4118 
4119   return DAG.getCopyFromReg(DAG.getEntryNode(), SL, VReg, VT);
4120 }
4121 
4122 // This may be called multiple times, and nothing prevents creating multiple
4123 // objects at the same offset. See if we already defined this object.
getOrCreateFixedStackObject(MachineFrameInfo & MFI,unsigned Size,int64_t Offset)4124 static int getOrCreateFixedStackObject(MachineFrameInfo &MFI, unsigned Size,
4125                                        int64_t Offset) {
4126   for (int I = MFI.getObjectIndexBegin(); I < 0; ++I) {
4127     if (MFI.getObjectOffset(I) == Offset) {
4128       assert(MFI.getObjectSize(I) == Size);
4129       return I;
4130     }
4131   }
4132 
4133   return MFI.CreateFixedObject(Size, Offset, true);
4134 }
4135 
loadStackInputValue(SelectionDAG & DAG,EVT VT,const SDLoc & SL,int64_t Offset) const4136 SDValue AMDGPUTargetLowering::loadStackInputValue(SelectionDAG &DAG,
4137                                                   EVT VT,
4138                                                   const SDLoc &SL,
4139                                                   int64_t Offset) const {
4140   MachineFunction &MF = DAG.getMachineFunction();
4141   MachineFrameInfo &MFI = MF.getFrameInfo();
4142   int FI = getOrCreateFixedStackObject(MFI, VT.getStoreSize(), Offset);
4143 
4144   auto SrcPtrInfo = MachinePointerInfo::getStack(MF, Offset);
4145   SDValue Ptr = DAG.getFrameIndex(FI, MVT::i32);
4146 
4147   return DAG.getLoad(VT, SL, DAG.getEntryNode(), Ptr, SrcPtrInfo, Align(4),
4148                      MachineMemOperand::MODereferenceable |
4149                          MachineMemOperand::MOInvariant);
4150 }
4151 
storeStackInputValue(SelectionDAG & DAG,const SDLoc & SL,SDValue Chain,SDValue ArgVal,int64_t Offset) const4152 SDValue AMDGPUTargetLowering::storeStackInputValue(SelectionDAG &DAG,
4153                                                    const SDLoc &SL,
4154                                                    SDValue Chain,
4155                                                    SDValue ArgVal,
4156                                                    int64_t Offset) const {
4157   MachineFunction &MF = DAG.getMachineFunction();
4158   MachinePointerInfo DstInfo = MachinePointerInfo::getStack(MF, Offset);
4159 
4160   SDValue Ptr = DAG.getConstant(Offset, SL, MVT::i32);
4161   SDValue Store = DAG.getStore(Chain, SL, ArgVal, Ptr, DstInfo, Align(4),
4162                                MachineMemOperand::MODereferenceable);
4163   return Store;
4164 }
4165 
loadInputValue(SelectionDAG & DAG,const TargetRegisterClass * RC,EVT VT,const SDLoc & SL,const ArgDescriptor & Arg) const4166 SDValue AMDGPUTargetLowering::loadInputValue(SelectionDAG &DAG,
4167                                              const TargetRegisterClass *RC,
4168                                              EVT VT, const SDLoc &SL,
4169                                              const ArgDescriptor &Arg) const {
4170   assert(Arg && "Attempting to load missing argument");
4171 
4172   SDValue V = Arg.isRegister() ?
4173     CreateLiveInRegister(DAG, RC, Arg.getRegister(), VT, SL) :
4174     loadStackInputValue(DAG, VT, SL, Arg.getStackOffset());
4175 
4176   if (!Arg.isMasked())
4177     return V;
4178 
4179   unsigned Mask = Arg.getMask();
4180   unsigned Shift = countTrailingZeros<unsigned>(Mask);
4181   V = DAG.getNode(ISD::SRL, SL, VT, V,
4182                   DAG.getShiftAmountConstant(Shift, VT, SL));
4183   return DAG.getNode(ISD::AND, SL, VT, V,
4184                      DAG.getConstant(Mask >> Shift, SL, VT));
4185 }
4186 
getImplicitParameterOffset(const MachineFunction & MF,const ImplicitParameter Param) const4187 uint32_t AMDGPUTargetLowering::getImplicitParameterOffset(
4188     const MachineFunction &MF, const ImplicitParameter Param) const {
4189   const AMDGPUMachineFunction *MFI = MF.getInfo<AMDGPUMachineFunction>();
4190   const AMDGPUSubtarget &ST =
4191       AMDGPUSubtarget::get(getTargetMachine(), MF.getFunction());
4192   unsigned ExplicitArgOffset = ST.getExplicitKernelArgOffset(MF.getFunction());
4193   const Align Alignment = ST.getAlignmentForImplicitArgPtr();
4194   uint64_t ArgOffset = alignTo(MFI->getExplicitKernArgSize(), Alignment) +
4195                        ExplicitArgOffset;
4196   switch (Param) {
4197   case GRID_DIM:
4198     return ArgOffset;
4199   case GRID_OFFSET:
4200     return ArgOffset + 4;
4201   }
4202   llvm_unreachable("unexpected implicit parameter type");
4203 }
4204 
4205 #define NODE_NAME_CASE(node) case AMDGPUISD::node: return #node;
4206 
getTargetNodeName(unsigned Opcode) const4207 const char* AMDGPUTargetLowering::getTargetNodeName(unsigned Opcode) const {
4208   switch ((AMDGPUISD::NodeType)Opcode) {
4209   case AMDGPUISD::FIRST_NUMBER: break;
4210   // AMDIL DAG nodes
4211   NODE_NAME_CASE(UMUL);
4212   NODE_NAME_CASE(BRANCH_COND);
4213 
4214   // AMDGPU DAG nodes
4215   NODE_NAME_CASE(IF)
4216   NODE_NAME_CASE(ELSE)
4217   NODE_NAME_CASE(LOOP)
4218   NODE_NAME_CASE(CALL)
4219   NODE_NAME_CASE(TC_RETURN)
4220   NODE_NAME_CASE(TRAP)
4221   NODE_NAME_CASE(RET_FLAG)
4222   NODE_NAME_CASE(RETURN_TO_EPILOG)
4223   NODE_NAME_CASE(ENDPGM)
4224   NODE_NAME_CASE(DWORDADDR)
4225   NODE_NAME_CASE(FRACT)
4226   NODE_NAME_CASE(SETCC)
4227   NODE_NAME_CASE(SETREG)
4228   NODE_NAME_CASE(DENORM_MODE)
4229   NODE_NAME_CASE(FMA_W_CHAIN)
4230   NODE_NAME_CASE(FMUL_W_CHAIN)
4231   NODE_NAME_CASE(CLAMP)
4232   NODE_NAME_CASE(COS_HW)
4233   NODE_NAME_CASE(SIN_HW)
4234   NODE_NAME_CASE(FMAX_LEGACY)
4235   NODE_NAME_CASE(FMIN_LEGACY)
4236   NODE_NAME_CASE(FMAX3)
4237   NODE_NAME_CASE(SMAX3)
4238   NODE_NAME_CASE(UMAX3)
4239   NODE_NAME_CASE(FMIN3)
4240   NODE_NAME_CASE(SMIN3)
4241   NODE_NAME_CASE(UMIN3)
4242   NODE_NAME_CASE(FMED3)
4243   NODE_NAME_CASE(SMED3)
4244   NODE_NAME_CASE(UMED3)
4245   NODE_NAME_CASE(FDOT2)
4246   NODE_NAME_CASE(URECIP)
4247   NODE_NAME_CASE(DIV_SCALE)
4248   NODE_NAME_CASE(DIV_FMAS)
4249   NODE_NAME_CASE(DIV_FIXUP)
4250   NODE_NAME_CASE(FMAD_FTZ)
4251   NODE_NAME_CASE(RCP)
4252   NODE_NAME_CASE(RSQ)
4253   NODE_NAME_CASE(RCP_LEGACY)
4254   NODE_NAME_CASE(RCP_IFLAG)
4255   NODE_NAME_CASE(FMUL_LEGACY)
4256   NODE_NAME_CASE(RSQ_CLAMP)
4257   NODE_NAME_CASE(LDEXP)
4258   NODE_NAME_CASE(FP_CLASS)
4259   NODE_NAME_CASE(DOT4)
4260   NODE_NAME_CASE(CARRY)
4261   NODE_NAME_CASE(BORROW)
4262   NODE_NAME_CASE(BFE_U32)
4263   NODE_NAME_CASE(BFE_I32)
4264   NODE_NAME_CASE(BFI)
4265   NODE_NAME_CASE(BFM)
4266   NODE_NAME_CASE(FFBH_U32)
4267   NODE_NAME_CASE(FFBH_I32)
4268   NODE_NAME_CASE(FFBL_B32)
4269   NODE_NAME_CASE(MUL_U24)
4270   NODE_NAME_CASE(MUL_I24)
4271   NODE_NAME_CASE(MULHI_U24)
4272   NODE_NAME_CASE(MULHI_I24)
4273   NODE_NAME_CASE(MAD_U24)
4274   NODE_NAME_CASE(MAD_I24)
4275   NODE_NAME_CASE(MAD_I64_I32)
4276   NODE_NAME_CASE(MAD_U64_U32)
4277   NODE_NAME_CASE(PERM)
4278   NODE_NAME_CASE(TEXTURE_FETCH)
4279   NODE_NAME_CASE(R600_EXPORT)
4280   NODE_NAME_CASE(CONST_ADDRESS)
4281   NODE_NAME_CASE(REGISTER_LOAD)
4282   NODE_NAME_CASE(REGISTER_STORE)
4283   NODE_NAME_CASE(SAMPLE)
4284   NODE_NAME_CASE(SAMPLEB)
4285   NODE_NAME_CASE(SAMPLED)
4286   NODE_NAME_CASE(SAMPLEL)
4287   NODE_NAME_CASE(CVT_F32_UBYTE0)
4288   NODE_NAME_CASE(CVT_F32_UBYTE1)
4289   NODE_NAME_CASE(CVT_F32_UBYTE2)
4290   NODE_NAME_CASE(CVT_F32_UBYTE3)
4291   NODE_NAME_CASE(CVT_PKRTZ_F16_F32)
4292   NODE_NAME_CASE(CVT_PKNORM_I16_F32)
4293   NODE_NAME_CASE(CVT_PKNORM_U16_F32)
4294   NODE_NAME_CASE(CVT_PK_I16_I32)
4295   NODE_NAME_CASE(CVT_PK_U16_U32)
4296   NODE_NAME_CASE(FP_TO_FP16)
4297   NODE_NAME_CASE(FP16_ZEXT)
4298   NODE_NAME_CASE(BUILD_VERTICAL_VECTOR)
4299   NODE_NAME_CASE(CONST_DATA_PTR)
4300   NODE_NAME_CASE(PC_ADD_REL_OFFSET)
4301   NODE_NAME_CASE(LDS)
4302   NODE_NAME_CASE(DUMMY_CHAIN)
4303   case AMDGPUISD::FIRST_MEM_OPCODE_NUMBER: break;
4304   NODE_NAME_CASE(LOAD_D16_HI)
4305   NODE_NAME_CASE(LOAD_D16_LO)
4306   NODE_NAME_CASE(LOAD_D16_HI_I8)
4307   NODE_NAME_CASE(LOAD_D16_HI_U8)
4308   NODE_NAME_CASE(LOAD_D16_LO_I8)
4309   NODE_NAME_CASE(LOAD_D16_LO_U8)
4310   NODE_NAME_CASE(STORE_MSKOR)
4311   NODE_NAME_CASE(LOAD_CONSTANT)
4312   NODE_NAME_CASE(TBUFFER_STORE_FORMAT)
4313   NODE_NAME_CASE(TBUFFER_STORE_FORMAT_D16)
4314   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT)
4315   NODE_NAME_CASE(TBUFFER_LOAD_FORMAT_D16)
4316   NODE_NAME_CASE(DS_ORDERED_COUNT)
4317   NODE_NAME_CASE(ATOMIC_CMP_SWAP)
4318   NODE_NAME_CASE(ATOMIC_INC)
4319   NODE_NAME_CASE(ATOMIC_DEC)
4320   NODE_NAME_CASE(ATOMIC_LOAD_FMIN)
4321   NODE_NAME_CASE(ATOMIC_LOAD_FMAX)
4322   NODE_NAME_CASE(BUFFER_LOAD)
4323   NODE_NAME_CASE(BUFFER_LOAD_UBYTE)
4324   NODE_NAME_CASE(BUFFER_LOAD_USHORT)
4325   NODE_NAME_CASE(BUFFER_LOAD_BYTE)
4326   NODE_NAME_CASE(BUFFER_LOAD_SHORT)
4327   NODE_NAME_CASE(BUFFER_LOAD_FORMAT)
4328   NODE_NAME_CASE(BUFFER_LOAD_FORMAT_D16)
4329   NODE_NAME_CASE(SBUFFER_LOAD)
4330   NODE_NAME_CASE(BUFFER_STORE)
4331   NODE_NAME_CASE(BUFFER_STORE_BYTE)
4332   NODE_NAME_CASE(BUFFER_STORE_SHORT)
4333   NODE_NAME_CASE(BUFFER_STORE_FORMAT)
4334   NODE_NAME_CASE(BUFFER_STORE_FORMAT_D16)
4335   NODE_NAME_CASE(BUFFER_ATOMIC_SWAP)
4336   NODE_NAME_CASE(BUFFER_ATOMIC_ADD)
4337   NODE_NAME_CASE(BUFFER_ATOMIC_SUB)
4338   NODE_NAME_CASE(BUFFER_ATOMIC_SMIN)
4339   NODE_NAME_CASE(BUFFER_ATOMIC_UMIN)
4340   NODE_NAME_CASE(BUFFER_ATOMIC_SMAX)
4341   NODE_NAME_CASE(BUFFER_ATOMIC_UMAX)
4342   NODE_NAME_CASE(BUFFER_ATOMIC_AND)
4343   NODE_NAME_CASE(BUFFER_ATOMIC_OR)
4344   NODE_NAME_CASE(BUFFER_ATOMIC_XOR)
4345   NODE_NAME_CASE(BUFFER_ATOMIC_INC)
4346   NODE_NAME_CASE(BUFFER_ATOMIC_DEC)
4347   NODE_NAME_CASE(BUFFER_ATOMIC_CMPSWAP)
4348   NODE_NAME_CASE(BUFFER_ATOMIC_CSUB)
4349   NODE_NAME_CASE(BUFFER_ATOMIC_FADD)
4350   NODE_NAME_CASE(BUFFER_ATOMIC_FMIN)
4351   NODE_NAME_CASE(BUFFER_ATOMIC_FMAX)
4352 
4353   case AMDGPUISD::LAST_AMDGPU_ISD_NUMBER: break;
4354   }
4355   return nullptr;
4356 }
4357 
getSqrtEstimate(SDValue Operand,SelectionDAG & DAG,int Enabled,int & RefinementSteps,bool & UseOneConstNR,bool Reciprocal) const4358 SDValue AMDGPUTargetLowering::getSqrtEstimate(SDValue Operand,
4359                                               SelectionDAG &DAG, int Enabled,
4360                                               int &RefinementSteps,
4361                                               bool &UseOneConstNR,
4362                                               bool Reciprocal) const {
4363   EVT VT = Operand.getValueType();
4364 
4365   if (VT == MVT::f32) {
4366     RefinementSteps = 0;
4367     return DAG.getNode(AMDGPUISD::RSQ, SDLoc(Operand), VT, Operand);
4368   }
4369 
4370   // TODO: There is also f64 rsq instruction, but the documentation is less
4371   // clear on its precision.
4372 
4373   return SDValue();
4374 }
4375 
getRecipEstimate(SDValue Operand,SelectionDAG & DAG,int Enabled,int & RefinementSteps) const4376 SDValue AMDGPUTargetLowering::getRecipEstimate(SDValue Operand,
4377                                                SelectionDAG &DAG, int Enabled,
4378                                                int &RefinementSteps) const {
4379   EVT VT = Operand.getValueType();
4380 
4381   if (VT == MVT::f32) {
4382     // Reciprocal, < 1 ulp error.
4383     //
4384     // This reciprocal approximation converges to < 0.5 ulp error with one
4385     // newton rhapson performed with two fused multiple adds (FMAs).
4386 
4387     RefinementSteps = 0;
4388     return DAG.getNode(AMDGPUISD::RCP, SDLoc(Operand), VT, Operand);
4389   }
4390 
4391   // TODO: There is also f64 rcp instruction, but the documentation is less
4392   // clear on its precision.
4393 
4394   return SDValue();
4395 }
4396 
computeKnownBitsForTargetNode(const SDValue Op,KnownBits & Known,const APInt & DemandedElts,const SelectionDAG & DAG,unsigned Depth) const4397 void AMDGPUTargetLowering::computeKnownBitsForTargetNode(
4398     const SDValue Op, KnownBits &Known,
4399     const APInt &DemandedElts, const SelectionDAG &DAG, unsigned Depth) const {
4400 
4401   Known.resetAll(); // Don't know anything.
4402 
4403   unsigned Opc = Op.getOpcode();
4404 
4405   switch (Opc) {
4406   default:
4407     break;
4408   case AMDGPUISD::CARRY:
4409   case AMDGPUISD::BORROW: {
4410     Known.Zero = APInt::getHighBitsSet(32, 31);
4411     break;
4412   }
4413 
4414   case AMDGPUISD::BFE_I32:
4415   case AMDGPUISD::BFE_U32: {
4416     ConstantSDNode *CWidth = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4417     if (!CWidth)
4418       return;
4419 
4420     uint32_t Width = CWidth->getZExtValue() & 0x1f;
4421 
4422     if (Opc == AMDGPUISD::BFE_U32)
4423       Known.Zero = APInt::getHighBitsSet(32, 32 - Width);
4424 
4425     break;
4426   }
4427   case AMDGPUISD::FP_TO_FP16:
4428   case AMDGPUISD::FP16_ZEXT: {
4429     unsigned BitWidth = Known.getBitWidth();
4430 
4431     // High bits are zero.
4432     Known.Zero = APInt::getHighBitsSet(BitWidth, BitWidth - 16);
4433     break;
4434   }
4435   case AMDGPUISD::MUL_U24:
4436   case AMDGPUISD::MUL_I24: {
4437     KnownBits LHSKnown = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
4438     KnownBits RHSKnown = DAG.computeKnownBits(Op.getOperand(1), Depth + 1);
4439     unsigned TrailZ = LHSKnown.countMinTrailingZeros() +
4440                       RHSKnown.countMinTrailingZeros();
4441     Known.Zero.setLowBits(std::min(TrailZ, 32u));
4442     // Skip extra check if all bits are known zeros.
4443     if (TrailZ >= 32)
4444       break;
4445 
4446     // Truncate to 24 bits.
4447     LHSKnown = LHSKnown.trunc(24);
4448     RHSKnown = RHSKnown.trunc(24);
4449 
4450     if (Opc == AMDGPUISD::MUL_I24) {
4451       unsigned LHSValBits = 24 - LHSKnown.countMinSignBits();
4452       unsigned RHSValBits = 24 - RHSKnown.countMinSignBits();
4453       unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4454       if (MaxValBits >= 32)
4455         break;
4456       bool LHSNegative = LHSKnown.isNegative();
4457       bool LHSNonNegative = LHSKnown.isNonNegative();
4458       bool LHSPositive = LHSKnown.isStrictlyPositive();
4459       bool RHSNegative = RHSKnown.isNegative();
4460       bool RHSNonNegative = RHSKnown.isNonNegative();
4461       bool RHSPositive = RHSKnown.isStrictlyPositive();
4462 
4463       if ((LHSNonNegative && RHSNonNegative) || (LHSNegative && RHSNegative))
4464         Known.Zero.setHighBits(32 - MaxValBits);
4465       else if ((LHSNegative && RHSPositive) || (LHSPositive && RHSNegative))
4466         Known.One.setHighBits(32 - MaxValBits);
4467     } else {
4468       unsigned LHSValBits = 24 - LHSKnown.countMinLeadingZeros();
4469       unsigned RHSValBits = 24 - RHSKnown.countMinLeadingZeros();
4470       unsigned MaxValBits = std::min(LHSValBits + RHSValBits, 32u);
4471       if (MaxValBits >= 32)
4472         break;
4473       Known.Zero.setHighBits(32 - MaxValBits);
4474     }
4475     break;
4476   }
4477   case AMDGPUISD::PERM: {
4478     ConstantSDNode *CMask = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4479     if (!CMask)
4480       return;
4481 
4482     KnownBits LHSKnown = DAG.computeKnownBits(Op.getOperand(0), Depth + 1);
4483     KnownBits RHSKnown = DAG.computeKnownBits(Op.getOperand(1), Depth + 1);
4484     unsigned Sel = CMask->getZExtValue();
4485 
4486     for (unsigned I = 0; I < 32; I += 8) {
4487       unsigned SelBits = Sel & 0xff;
4488       if (SelBits < 4) {
4489         SelBits *= 8;
4490         Known.One |= ((RHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4491         Known.Zero |= ((RHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4492       } else if (SelBits < 7) {
4493         SelBits = (SelBits & 3) * 8;
4494         Known.One |= ((LHSKnown.One.getZExtValue() >> SelBits) & 0xff) << I;
4495         Known.Zero |= ((LHSKnown.Zero.getZExtValue() >> SelBits) & 0xff) << I;
4496       } else if (SelBits == 0x0c) {
4497         Known.Zero |= 0xFFull << I;
4498       } else if (SelBits > 0x0c) {
4499         Known.One |= 0xFFull << I;
4500       }
4501       Sel >>= 8;
4502     }
4503     break;
4504   }
4505   case AMDGPUISD::BUFFER_LOAD_UBYTE:  {
4506     Known.Zero.setHighBits(24);
4507     break;
4508   }
4509   case AMDGPUISD::BUFFER_LOAD_USHORT: {
4510     Known.Zero.setHighBits(16);
4511     break;
4512   }
4513   case AMDGPUISD::LDS: {
4514     auto GA = cast<GlobalAddressSDNode>(Op.getOperand(0).getNode());
4515     Align Alignment = GA->getGlobal()->getPointerAlignment(DAG.getDataLayout());
4516 
4517     Known.Zero.setHighBits(16);
4518     Known.Zero.setLowBits(Log2(Alignment));
4519     break;
4520   }
4521   case ISD::INTRINSIC_WO_CHAIN: {
4522     unsigned IID = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4523     switch (IID) {
4524     case Intrinsic::amdgcn_mbcnt_lo:
4525     case Intrinsic::amdgcn_mbcnt_hi: {
4526       const GCNSubtarget &ST =
4527           DAG.getMachineFunction().getSubtarget<GCNSubtarget>();
4528       // These return at most the wavefront size - 1.
4529       unsigned Size = Op.getValueType().getSizeInBits();
4530       Known.Zero.setHighBits(Size - ST.getWavefrontSizeLog2());
4531       break;
4532     }
4533     default:
4534       break;
4535     }
4536   }
4537   }
4538 }
4539 
ComputeNumSignBitsForTargetNode(SDValue Op,const APInt & DemandedElts,const SelectionDAG & DAG,unsigned Depth) const4540 unsigned AMDGPUTargetLowering::ComputeNumSignBitsForTargetNode(
4541     SDValue Op, const APInt &DemandedElts, const SelectionDAG &DAG,
4542     unsigned Depth) const {
4543   switch (Op.getOpcode()) {
4544   case AMDGPUISD::BFE_I32: {
4545     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4546     if (!Width)
4547       return 1;
4548 
4549     unsigned SignBits = 32 - Width->getZExtValue() + 1;
4550     if (!isNullConstant(Op.getOperand(1)))
4551       return SignBits;
4552 
4553     // TODO: Could probably figure something out with non-0 offsets.
4554     unsigned Op0SignBits = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
4555     return std::max(SignBits, Op0SignBits);
4556   }
4557 
4558   case AMDGPUISD::BFE_U32: {
4559     ConstantSDNode *Width = dyn_cast<ConstantSDNode>(Op.getOperand(2));
4560     return Width ? 32 - (Width->getZExtValue() & 0x1f) : 1;
4561   }
4562 
4563   case AMDGPUISD::CARRY:
4564   case AMDGPUISD::BORROW:
4565     return 31;
4566   case AMDGPUISD::BUFFER_LOAD_BYTE:
4567     return 25;
4568   case AMDGPUISD::BUFFER_LOAD_SHORT:
4569     return 17;
4570   case AMDGPUISD::BUFFER_LOAD_UBYTE:
4571     return 24;
4572   case AMDGPUISD::BUFFER_LOAD_USHORT:
4573     return 16;
4574   case AMDGPUISD::FP_TO_FP16:
4575   case AMDGPUISD::FP16_ZEXT:
4576     return 16;
4577   default:
4578     return 1;
4579   }
4580 }
4581 
computeNumSignBitsForTargetInstr(GISelKnownBits & Analysis,Register R,const APInt & DemandedElts,const MachineRegisterInfo & MRI,unsigned Depth) const4582 unsigned AMDGPUTargetLowering::computeNumSignBitsForTargetInstr(
4583   GISelKnownBits &Analysis, Register R,
4584   const APInt &DemandedElts, const MachineRegisterInfo &MRI,
4585   unsigned Depth) const {
4586   const MachineInstr *MI = MRI.getVRegDef(R);
4587   if (!MI)
4588     return 1;
4589 
4590   // TODO: Check range metadata on MMO.
4591   switch (MI->getOpcode()) {
4592   case AMDGPU::G_AMDGPU_BUFFER_LOAD_SBYTE:
4593     return 25;
4594   case AMDGPU::G_AMDGPU_BUFFER_LOAD_SSHORT:
4595     return 17;
4596   case AMDGPU::G_AMDGPU_BUFFER_LOAD_UBYTE:
4597     return 24;
4598   case AMDGPU::G_AMDGPU_BUFFER_LOAD_USHORT:
4599     return 16;
4600   default:
4601     return 1;
4602   }
4603 }
4604 
isKnownNeverNaNForTargetNode(SDValue Op,const SelectionDAG & DAG,bool SNaN,unsigned Depth) const4605 bool AMDGPUTargetLowering::isKnownNeverNaNForTargetNode(SDValue Op,
4606                                                         const SelectionDAG &DAG,
4607                                                         bool SNaN,
4608                                                         unsigned Depth) const {
4609   unsigned Opcode = Op.getOpcode();
4610   switch (Opcode) {
4611   case AMDGPUISD::FMIN_LEGACY:
4612   case AMDGPUISD::FMAX_LEGACY: {
4613     if (SNaN)
4614       return true;
4615 
4616     // TODO: Can check no nans on one of the operands for each one, but which
4617     // one?
4618     return false;
4619   }
4620   case AMDGPUISD::FMUL_LEGACY:
4621   case AMDGPUISD::CVT_PKRTZ_F16_F32: {
4622     if (SNaN)
4623       return true;
4624     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4625            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4626   }
4627   case AMDGPUISD::FMED3:
4628   case AMDGPUISD::FMIN3:
4629   case AMDGPUISD::FMAX3:
4630   case AMDGPUISD::FMAD_FTZ: {
4631     if (SNaN)
4632       return true;
4633     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1) &&
4634            DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4635            DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4636   }
4637   case AMDGPUISD::CVT_F32_UBYTE0:
4638   case AMDGPUISD::CVT_F32_UBYTE1:
4639   case AMDGPUISD::CVT_F32_UBYTE2:
4640   case AMDGPUISD::CVT_F32_UBYTE3:
4641     return true;
4642 
4643   case AMDGPUISD::RCP:
4644   case AMDGPUISD::RSQ:
4645   case AMDGPUISD::RCP_LEGACY:
4646   case AMDGPUISD::RSQ_CLAMP: {
4647     if (SNaN)
4648       return true;
4649 
4650     // TODO: Need is known positive check.
4651     return false;
4652   }
4653   case AMDGPUISD::LDEXP:
4654   case AMDGPUISD::FRACT: {
4655     if (SNaN)
4656       return true;
4657     return DAG.isKnownNeverNaN(Op.getOperand(0), SNaN, Depth + 1);
4658   }
4659   case AMDGPUISD::DIV_SCALE:
4660   case AMDGPUISD::DIV_FMAS:
4661   case AMDGPUISD::DIV_FIXUP:
4662     // TODO: Refine on operands.
4663     return SNaN;
4664   case AMDGPUISD::SIN_HW:
4665   case AMDGPUISD::COS_HW: {
4666     // TODO: Need check for infinity
4667     return SNaN;
4668   }
4669   case ISD::INTRINSIC_WO_CHAIN: {
4670     unsigned IntrinsicID
4671       = cast<ConstantSDNode>(Op.getOperand(0))->getZExtValue();
4672     // TODO: Handle more intrinsics
4673     switch (IntrinsicID) {
4674     case Intrinsic::amdgcn_cubeid:
4675       return true;
4676 
4677     case Intrinsic::amdgcn_frexp_mant: {
4678       if (SNaN)
4679         return true;
4680       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1);
4681     }
4682     case Intrinsic::amdgcn_cvt_pkrtz: {
4683       if (SNaN)
4684         return true;
4685       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4686              DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1);
4687     }
4688     case Intrinsic::amdgcn_rcp:
4689     case Intrinsic::amdgcn_rsq:
4690     case Intrinsic::amdgcn_rcp_legacy:
4691     case Intrinsic::amdgcn_rsq_legacy:
4692     case Intrinsic::amdgcn_rsq_clamp: {
4693       if (SNaN)
4694         return true;
4695 
4696       // TODO: Need is known positive check.
4697       return false;
4698     }
4699     case Intrinsic::amdgcn_trig_preop:
4700     case Intrinsic::amdgcn_fdot2:
4701       // TODO: Refine on operand
4702       return SNaN;
4703     case Intrinsic::amdgcn_fma_legacy:
4704       if (SNaN)
4705         return true;
4706       return DAG.isKnownNeverNaN(Op.getOperand(1), SNaN, Depth + 1) &&
4707              DAG.isKnownNeverNaN(Op.getOperand(2), SNaN, Depth + 1) &&
4708              DAG.isKnownNeverNaN(Op.getOperand(3), SNaN, Depth + 1);
4709     default:
4710       return false;
4711     }
4712   }
4713   default:
4714     return false;
4715   }
4716 }
4717 
4718 TargetLowering::AtomicExpansionKind
shouldExpandAtomicRMWInIR(AtomicRMWInst * RMW) const4719 AMDGPUTargetLowering::shouldExpandAtomicRMWInIR(AtomicRMWInst *RMW) const {
4720   switch (RMW->getOperation()) {
4721   case AtomicRMWInst::Nand:
4722   case AtomicRMWInst::FAdd:
4723   case AtomicRMWInst::FSub:
4724     return AtomicExpansionKind::CmpXChg;
4725   default:
4726     return AtomicExpansionKind::None;
4727   }
4728 }
4729