1 //===-- AMDGPUTargetStreamer.cpp - Mips Target Streamer Methods -----------===//
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 // This file provides AMDGPU specific target streamer methods.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "AMDGPUTargetStreamer.h"
14 #include "AMDGPUPTNote.h"
15 #include "AMDKernelCodeT.h"
16 #include "Utils/AMDGPUBaseInfo.h"
17 #include "Utils/AMDKernelCodeTUtils.h"
18 #include "llvm/BinaryFormat/AMDGPUMetadataVerifier.h"
19 #include "llvm/BinaryFormat/ELF.h"
20 #include "llvm/MC/MCAssembler.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCELFStreamer.h"
23 #include "llvm/MC/MCSectionELF.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 #include "llvm/Support/AMDGPUMetadata.h"
26 #include "llvm/Support/AMDHSAKernelDescriptor.h"
27 #include "llvm/Support/Casting.h"
28 #include "llvm/Support/FormattedStream.h"
29 #include "llvm/Support/TargetParser.h"
30 
31 using namespace llvm;
32 using namespace llvm::AMDGPU;
33 
34 //===----------------------------------------------------------------------===//
35 // AMDGPUTargetStreamer
36 //===----------------------------------------------------------------------===//
37 
38 static void convertIsaVersionV2(uint32_t &Major, uint32_t &Minor,
39                                 uint32_t &Stepping, bool Sramecc, bool Xnack) {
40   if (Major == 9 && Minor == 0) {
41     switch (Stepping) {
42       case 0:
43       case 2:
44       case 4:
45       case 6:
46         if (Xnack)
47           Stepping++;
48     }
49   }
50 }
51 
52 bool AMDGPUTargetStreamer::EmitHSAMetadataV2(StringRef HSAMetadataString) {
53   HSAMD::Metadata HSAMetadata;
54   if (HSAMD::fromString(HSAMetadataString, HSAMetadata))
55     return false;
56   return EmitHSAMetadata(HSAMetadata);
57 }
58 
59 bool AMDGPUTargetStreamer::EmitHSAMetadataV3(StringRef HSAMetadataString) {
60   msgpack::Document HSAMetadataDoc;
61   if (!HSAMetadataDoc.fromYAML(HSAMetadataString))
62     return false;
63   return EmitHSAMetadata(HSAMetadataDoc, false);
64 }
65 
66 StringRef AMDGPUTargetStreamer::getArchNameFromElfMach(unsigned ElfMach) {
67   AMDGPU::GPUKind AK;
68 
69   switch (ElfMach) {
70   default: llvm_unreachable("Unhandled ELF::EF_AMDGPU type");
71   case ELF::EF_AMDGPU_MACH_R600_R600:      AK = GK_R600;    break;
72   case ELF::EF_AMDGPU_MACH_R600_R630:      AK = GK_R630;    break;
73   case ELF::EF_AMDGPU_MACH_R600_RS880:     AK = GK_RS880;   break;
74   case ELF::EF_AMDGPU_MACH_R600_RV670:     AK = GK_RV670;   break;
75   case ELF::EF_AMDGPU_MACH_R600_RV710:     AK = GK_RV710;   break;
76   case ELF::EF_AMDGPU_MACH_R600_RV730:     AK = GK_RV730;   break;
77   case ELF::EF_AMDGPU_MACH_R600_RV770:     AK = GK_RV770;   break;
78   case ELF::EF_AMDGPU_MACH_R600_CEDAR:     AK = GK_CEDAR;   break;
79   case ELF::EF_AMDGPU_MACH_R600_CYPRESS:   AK = GK_CYPRESS; break;
80   case ELF::EF_AMDGPU_MACH_R600_JUNIPER:   AK = GK_JUNIPER; break;
81   case ELF::EF_AMDGPU_MACH_R600_REDWOOD:   AK = GK_REDWOOD; break;
82   case ELF::EF_AMDGPU_MACH_R600_SUMO:      AK = GK_SUMO;    break;
83   case ELF::EF_AMDGPU_MACH_R600_BARTS:     AK = GK_BARTS;   break;
84   case ELF::EF_AMDGPU_MACH_R600_CAICOS:    AK = GK_CAICOS;  break;
85   case ELF::EF_AMDGPU_MACH_R600_CAYMAN:    AK = GK_CAYMAN;  break;
86   case ELF::EF_AMDGPU_MACH_R600_TURKS:     AK = GK_TURKS;   break;
87   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX600:  AK = GK_GFX600;  break;
88   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX601:  AK = GK_GFX601;  break;
89   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX602:  AK = GK_GFX602;  break;
90   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX700:  AK = GK_GFX700;  break;
91   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX701:  AK = GK_GFX701;  break;
92   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX702:  AK = GK_GFX702;  break;
93   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX703:  AK = GK_GFX703;  break;
94   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX704:  AK = GK_GFX704;  break;
95   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX705:  AK = GK_GFX705;  break;
96   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX801:  AK = GK_GFX801;  break;
97   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX802:  AK = GK_GFX802;  break;
98   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX803:  AK = GK_GFX803;  break;
99   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX805:  AK = GK_GFX805;  break;
100   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX810:  AK = GK_GFX810;  break;
101   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX900:  AK = GK_GFX900;  break;
102   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX902:  AK = GK_GFX902;  break;
103   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX904:  AK = GK_GFX904;  break;
104   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX906:  AK = GK_GFX906;  break;
105   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX908:  AK = GK_GFX908;  break;
106   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX909:  AK = GK_GFX909;  break;
107   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90A:  AK = GK_GFX90A;  break;
108   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX90C:  AK = GK_GFX90C;  break;
109   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX940:  AK = GK_GFX940;  break;
110   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1010: AK = GK_GFX1010; break;
111   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1011: AK = GK_GFX1011; break;
112   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1012: AK = GK_GFX1012; break;
113   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1013: AK = GK_GFX1013; break;
114   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1030: AK = GK_GFX1030; break;
115   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1031: AK = GK_GFX1031; break;
116   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1032: AK = GK_GFX1032; break;
117   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1033: AK = GK_GFX1033; break;
118   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1034: AK = GK_GFX1034; break;
119   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1035: AK = GK_GFX1035; break;
120   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1036: AK = GK_GFX1036; break;
121   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1100: AK = GK_GFX1100; break;
122   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1101: AK = GK_GFX1101; break;
123   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1102: AK = GK_GFX1102; break;
124   case ELF::EF_AMDGPU_MACH_AMDGCN_GFX1103: AK = GK_GFX1103; break;
125   case ELF::EF_AMDGPU_MACH_NONE:           AK = GK_NONE;    break;
126   }
127 
128   StringRef GPUName = getArchNameAMDGCN(AK);
129   if (GPUName != "")
130     return GPUName;
131   return getArchNameR600(AK);
132 }
133 
134 unsigned AMDGPUTargetStreamer::getElfMach(StringRef GPU) {
135   AMDGPU::GPUKind AK = parseArchAMDGCN(GPU);
136   if (AK == AMDGPU::GPUKind::GK_NONE)
137     AK = parseArchR600(GPU);
138 
139   switch (AK) {
140   case GK_R600:    return ELF::EF_AMDGPU_MACH_R600_R600;
141   case GK_R630:    return ELF::EF_AMDGPU_MACH_R600_R630;
142   case GK_RS880:   return ELF::EF_AMDGPU_MACH_R600_RS880;
143   case GK_RV670:   return ELF::EF_AMDGPU_MACH_R600_RV670;
144   case GK_RV710:   return ELF::EF_AMDGPU_MACH_R600_RV710;
145   case GK_RV730:   return ELF::EF_AMDGPU_MACH_R600_RV730;
146   case GK_RV770:   return ELF::EF_AMDGPU_MACH_R600_RV770;
147   case GK_CEDAR:   return ELF::EF_AMDGPU_MACH_R600_CEDAR;
148   case GK_CYPRESS: return ELF::EF_AMDGPU_MACH_R600_CYPRESS;
149   case GK_JUNIPER: return ELF::EF_AMDGPU_MACH_R600_JUNIPER;
150   case GK_REDWOOD: return ELF::EF_AMDGPU_MACH_R600_REDWOOD;
151   case GK_SUMO:    return ELF::EF_AMDGPU_MACH_R600_SUMO;
152   case GK_BARTS:   return ELF::EF_AMDGPU_MACH_R600_BARTS;
153   case GK_CAICOS:  return ELF::EF_AMDGPU_MACH_R600_CAICOS;
154   case GK_CAYMAN:  return ELF::EF_AMDGPU_MACH_R600_CAYMAN;
155   case GK_TURKS:   return ELF::EF_AMDGPU_MACH_R600_TURKS;
156   case GK_GFX600:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX600;
157   case GK_GFX601:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX601;
158   case GK_GFX602:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX602;
159   case GK_GFX700:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX700;
160   case GK_GFX701:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX701;
161   case GK_GFX702:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX702;
162   case GK_GFX703:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX703;
163   case GK_GFX704:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX704;
164   case GK_GFX705:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX705;
165   case GK_GFX801:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX801;
166   case GK_GFX802:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX802;
167   case GK_GFX803:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX803;
168   case GK_GFX805:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX805;
169   case GK_GFX810:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX810;
170   case GK_GFX900:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX900;
171   case GK_GFX902:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX902;
172   case GK_GFX904:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX904;
173   case GK_GFX906:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX906;
174   case GK_GFX908:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX908;
175   case GK_GFX909:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX909;
176   case GK_GFX90A:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX90A;
177   case GK_GFX90C:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX90C;
178   case GK_GFX940:  return ELF::EF_AMDGPU_MACH_AMDGCN_GFX940;
179   case GK_GFX1010: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1010;
180   case GK_GFX1011: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1011;
181   case GK_GFX1012: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1012;
182   case GK_GFX1013: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1013;
183   case GK_GFX1030: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1030;
184   case GK_GFX1031: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1031;
185   case GK_GFX1032: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1032;
186   case GK_GFX1033: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1033;
187   case GK_GFX1034: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1034;
188   case GK_GFX1035: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1035;
189   case GK_GFX1036: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1036;
190   case GK_GFX1100: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1100;
191   case GK_GFX1101: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1101;
192   case GK_GFX1102: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1102;
193   case GK_GFX1103: return ELF::EF_AMDGPU_MACH_AMDGCN_GFX1103;
194   case GK_NONE:    return ELF::EF_AMDGPU_MACH_NONE;
195   }
196 
197   llvm_unreachable("unknown GPU");
198 }
199 
200 //===----------------------------------------------------------------------===//
201 // AMDGPUTargetAsmStreamer
202 //===----------------------------------------------------------------------===//
203 
204 AMDGPUTargetAsmStreamer::AMDGPUTargetAsmStreamer(MCStreamer &S,
205                                                  formatted_raw_ostream &OS)
206     : AMDGPUTargetStreamer(S), OS(OS) { }
207 
208 // A hook for emitting stuff at the end.
209 // We use it for emitting the accumulated PAL metadata as directives.
210 // The PAL metadata is reset after it is emitted.
211 void AMDGPUTargetAsmStreamer::finish() {
212   std::string S;
213   getPALMetadata()->toString(S);
214   OS << S;
215 
216   // Reset the pal metadata so its data will not affect a compilation that
217   // reuses this object.
218   getPALMetadata()->reset();
219 }
220 
221 void AMDGPUTargetAsmStreamer::EmitDirectiveAMDGCNTarget() {
222   OS << "\t.amdgcn_target \"" << getTargetID()->toString() << "\"\n";
223 }
224 
225 void AMDGPUTargetAsmStreamer::EmitDirectiveHSACodeObjectVersion(
226     uint32_t Major, uint32_t Minor) {
227   OS << "\t.hsa_code_object_version " <<
228         Twine(Major) << "," << Twine(Minor) << '\n';
229 }
230 
231 void
232 AMDGPUTargetAsmStreamer::EmitDirectiveHSACodeObjectISAV2(uint32_t Major,
233                                                          uint32_t Minor,
234                                                          uint32_t Stepping,
235                                                          StringRef VendorName,
236                                                          StringRef ArchName) {
237   convertIsaVersionV2(Major, Minor, Stepping, TargetID->isSramEccOnOrAny(), TargetID->isXnackOnOrAny());
238   OS << "\t.hsa_code_object_isa " << Twine(Major) << "," << Twine(Minor) << ","
239      << Twine(Stepping) << ",\"" << VendorName << "\",\"" << ArchName << "\"\n";
240 }
241 
242 void
243 AMDGPUTargetAsmStreamer::EmitAMDKernelCodeT(const amd_kernel_code_t &Header) {
244   OS << "\t.amd_kernel_code_t\n";
245   dumpAmdKernelCode(&Header, OS, "\t\t");
246   OS << "\t.end_amd_kernel_code_t\n";
247 }
248 
249 void AMDGPUTargetAsmStreamer::EmitAMDGPUSymbolType(StringRef SymbolName,
250                                                    unsigned Type) {
251   switch (Type) {
252     default: llvm_unreachable("Invalid AMDGPU symbol type");
253     case ELF::STT_AMDGPU_HSA_KERNEL:
254       OS << "\t.amdgpu_hsa_kernel " << SymbolName << '\n' ;
255       break;
256   }
257 }
258 
259 void AMDGPUTargetAsmStreamer::emitAMDGPULDS(MCSymbol *Symbol, unsigned Size,
260                                             Align Alignment) {
261   OS << "\t.amdgpu_lds " << Symbol->getName() << ", " << Size << ", "
262      << Alignment.value() << '\n';
263 }
264 
265 bool AMDGPUTargetAsmStreamer::EmitISAVersion() {
266   OS << "\t.amd_amdgpu_isa \"" << getTargetID()->toString() << "\"\n";
267   return true;
268 }
269 
270 bool AMDGPUTargetAsmStreamer::EmitHSAMetadata(
271     const AMDGPU::HSAMD::Metadata &HSAMetadata) {
272   std::string HSAMetadataString;
273   if (HSAMD::toString(HSAMetadata, HSAMetadataString))
274     return false;
275 
276   OS << '\t' << HSAMD::AssemblerDirectiveBegin << '\n';
277   OS << HSAMetadataString << '\n';
278   OS << '\t' << HSAMD::AssemblerDirectiveEnd << '\n';
279   return true;
280 }
281 
282 bool AMDGPUTargetAsmStreamer::EmitHSAMetadata(
283     msgpack::Document &HSAMetadataDoc, bool Strict) {
284   HSAMD::V3::MetadataVerifier Verifier(Strict);
285   if (!Verifier.verify(HSAMetadataDoc.getRoot()))
286     return false;
287 
288   std::string HSAMetadataString;
289   raw_string_ostream StrOS(HSAMetadataString);
290   HSAMetadataDoc.toYAML(StrOS);
291 
292   OS << '\t' << HSAMD::V3::AssemblerDirectiveBegin << '\n';
293   OS << StrOS.str() << '\n';
294   OS << '\t' << HSAMD::V3::AssemblerDirectiveEnd << '\n';
295   return true;
296 }
297 
298 bool AMDGPUTargetAsmStreamer::EmitCodeEnd(const MCSubtargetInfo &STI) {
299   const uint32_t Encoded_s_code_end = 0xbf9f0000;
300   const uint32_t Encoded_s_nop = 0xbf800000;
301   uint32_t Encoded_pad = Encoded_s_code_end;
302 
303   // Instruction cache line size in bytes.
304   const unsigned Log2CacheLineSize = AMDGPU::isGFX11Plus(STI) ? 7 : 6;
305   const unsigned CacheLineSize = 1u << Log2CacheLineSize;
306 
307   // Extra padding amount in bytes to support prefetch mode 3.
308   unsigned FillSize = 3 * CacheLineSize;
309 
310   if (AMDGPU::isGFX90A(STI)) {
311     Encoded_pad = Encoded_s_nop;
312     FillSize = 16 * CacheLineSize;
313   }
314 
315   OS << "\t.p2alignl " << Log2CacheLineSize << ", " << Encoded_pad << '\n';
316   OS << "\t.fill " << (FillSize / 4) << ", 4, " << Encoded_pad << '\n';
317   return true;
318 }
319 
320 void AMDGPUTargetAsmStreamer::EmitAmdhsaKernelDescriptor(
321     const MCSubtargetInfo &STI, StringRef KernelName,
322     const amdhsa::kernel_descriptor_t &KD, uint64_t NextVGPR, uint64_t NextSGPR,
323     bool ReserveVCC, bool ReserveFlatScr) {
324   IsaVersion IVersion = getIsaVersion(STI.getCPU());
325 
326   OS << "\t.amdhsa_kernel " << KernelName << '\n';
327 
328 #define PRINT_FIELD(STREAM, DIRECTIVE, KERNEL_DESC, MEMBER_NAME, FIELD_NAME)   \
329   STREAM << "\t\t" << DIRECTIVE << " "                                         \
330          << AMDHSA_BITS_GET(KERNEL_DESC.MEMBER_NAME, FIELD_NAME) << '\n';
331 
332   OS << "\t\t.amdhsa_group_segment_fixed_size " << KD.group_segment_fixed_size
333      << '\n';
334   OS << "\t\t.amdhsa_private_segment_fixed_size "
335      << KD.private_segment_fixed_size << '\n';
336   OS << "\t\t.amdhsa_kernarg_size " << KD.kernarg_size << '\n';
337 
338   PRINT_FIELD(OS, ".amdhsa_user_sgpr_count", KD,
339               compute_pgm_rsrc2,
340               amdhsa::COMPUTE_PGM_RSRC2_USER_SGPR_COUNT);
341 
342   if (!hasArchitectedFlatScratch(STI))
343     PRINT_FIELD(
344         OS, ".amdhsa_user_sgpr_private_segment_buffer", KD,
345         kernel_code_properties,
346         amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_PRIVATE_SEGMENT_BUFFER);
347   PRINT_FIELD(OS, ".amdhsa_user_sgpr_dispatch_ptr", KD,
348               kernel_code_properties,
349               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_DISPATCH_PTR);
350   PRINT_FIELD(OS, ".amdhsa_user_sgpr_queue_ptr", KD,
351               kernel_code_properties,
352               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_QUEUE_PTR);
353   PRINT_FIELD(OS, ".amdhsa_user_sgpr_kernarg_segment_ptr", KD,
354               kernel_code_properties,
355               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_KERNARG_SEGMENT_PTR);
356   PRINT_FIELD(OS, ".amdhsa_user_sgpr_dispatch_id", KD,
357               kernel_code_properties,
358               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_DISPATCH_ID);
359   if (!hasArchitectedFlatScratch(STI))
360     PRINT_FIELD(OS, ".amdhsa_user_sgpr_flat_scratch_init", KD,
361                 kernel_code_properties,
362                 amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_FLAT_SCRATCH_INIT);
363   PRINT_FIELD(OS, ".amdhsa_user_sgpr_private_segment_size", KD,
364               kernel_code_properties,
365               amdhsa::KERNEL_CODE_PROPERTY_ENABLE_SGPR_PRIVATE_SEGMENT_SIZE);
366   if (IVersion.Major >= 10)
367     PRINT_FIELD(OS, ".amdhsa_wavefront_size32", KD,
368                 kernel_code_properties,
369                 amdhsa::KERNEL_CODE_PROPERTY_ENABLE_WAVEFRONT_SIZE32);
370   PRINT_FIELD(OS, ".amdhsa_uses_dynamic_stack", KD, kernel_code_properties,
371               amdhsa::KERNEL_CODE_PROPERTY_USES_DYNAMIC_STACK);
372   PRINT_FIELD(OS,
373               (hasArchitectedFlatScratch(STI)
374                    ? ".amdhsa_enable_private_segment"
375                    : ".amdhsa_system_sgpr_private_segment_wavefront_offset"),
376               KD, compute_pgm_rsrc2,
377               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_PRIVATE_SEGMENT);
378   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_id_x", KD,
379               compute_pgm_rsrc2,
380               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_ID_X);
381   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_id_y", KD,
382               compute_pgm_rsrc2,
383               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_ID_Y);
384   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_id_z", KD,
385               compute_pgm_rsrc2,
386               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_ID_Z);
387   PRINT_FIELD(OS, ".amdhsa_system_sgpr_workgroup_info", KD,
388               compute_pgm_rsrc2,
389               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_SGPR_WORKGROUP_INFO);
390   PRINT_FIELD(OS, ".amdhsa_system_vgpr_workitem_id", KD,
391               compute_pgm_rsrc2,
392               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_VGPR_WORKITEM_ID);
393 
394   // These directives are required.
395   OS << "\t\t.amdhsa_next_free_vgpr " << NextVGPR << '\n';
396   OS << "\t\t.amdhsa_next_free_sgpr " << NextSGPR << '\n';
397 
398   if (AMDGPU::isGFX90A(STI))
399     OS << "\t\t.amdhsa_accum_offset " <<
400       (AMDHSA_BITS_GET(KD.compute_pgm_rsrc3,
401                        amdhsa::COMPUTE_PGM_RSRC3_GFX90A_ACCUM_OFFSET) + 1) * 4
402       << '\n';
403 
404   if (!ReserveVCC)
405     OS << "\t\t.amdhsa_reserve_vcc " << ReserveVCC << '\n';
406   if (IVersion.Major >= 7 && !ReserveFlatScr && !hasArchitectedFlatScratch(STI))
407     OS << "\t\t.amdhsa_reserve_flat_scratch " << ReserveFlatScr << '\n';
408 
409   if (Optional<uint8_t> HsaAbiVer = getHsaAbiVersion(&STI)) {
410     switch (*HsaAbiVer) {
411     default:
412       break;
413     case ELF::ELFABIVERSION_AMDGPU_HSA_V2:
414       break;
415     case ELF::ELFABIVERSION_AMDGPU_HSA_V3:
416     case ELF::ELFABIVERSION_AMDGPU_HSA_V4:
417     case ELF::ELFABIVERSION_AMDGPU_HSA_V5:
418       if (getTargetID()->isXnackSupported())
419         OS << "\t\t.amdhsa_reserve_xnack_mask " << getTargetID()->isXnackOnOrAny() << '\n';
420       break;
421     }
422   }
423 
424   PRINT_FIELD(OS, ".amdhsa_float_round_mode_32", KD,
425               compute_pgm_rsrc1,
426               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_ROUND_MODE_32);
427   PRINT_FIELD(OS, ".amdhsa_float_round_mode_16_64", KD,
428               compute_pgm_rsrc1,
429               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_ROUND_MODE_16_64);
430   PRINT_FIELD(OS, ".amdhsa_float_denorm_mode_32", KD,
431               compute_pgm_rsrc1,
432               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_DENORM_MODE_32);
433   PRINT_FIELD(OS, ".amdhsa_float_denorm_mode_16_64", KD,
434               compute_pgm_rsrc1,
435               amdhsa::COMPUTE_PGM_RSRC1_FLOAT_DENORM_MODE_16_64);
436   PRINT_FIELD(OS, ".amdhsa_dx10_clamp", KD,
437               compute_pgm_rsrc1,
438               amdhsa::COMPUTE_PGM_RSRC1_ENABLE_DX10_CLAMP);
439   PRINT_FIELD(OS, ".amdhsa_ieee_mode", KD,
440               compute_pgm_rsrc1,
441               amdhsa::COMPUTE_PGM_RSRC1_ENABLE_IEEE_MODE);
442   if (IVersion.Major >= 9)
443     PRINT_FIELD(OS, ".amdhsa_fp16_overflow", KD,
444                 compute_pgm_rsrc1,
445                 amdhsa::COMPUTE_PGM_RSRC1_FP16_OVFL);
446   if (AMDGPU::isGFX90A(STI))
447     PRINT_FIELD(OS, ".amdhsa_tg_split", KD,
448                 compute_pgm_rsrc3,
449                 amdhsa::COMPUTE_PGM_RSRC3_GFX90A_TG_SPLIT);
450   if (IVersion.Major >= 10) {
451     PRINT_FIELD(OS, ".amdhsa_workgroup_processor_mode", KD,
452                 compute_pgm_rsrc1,
453                 amdhsa::COMPUTE_PGM_RSRC1_WGP_MODE);
454     PRINT_FIELD(OS, ".amdhsa_memory_ordered", KD,
455                 compute_pgm_rsrc1,
456                 amdhsa::COMPUTE_PGM_RSRC1_MEM_ORDERED);
457     PRINT_FIELD(OS, ".amdhsa_forward_progress", KD,
458                 compute_pgm_rsrc1,
459                 amdhsa::COMPUTE_PGM_RSRC1_FWD_PROGRESS);
460     PRINT_FIELD(OS, ".amdhsa_shared_vgpr_count", KD, compute_pgm_rsrc3,
461                 amdhsa::COMPUTE_PGM_RSRC3_GFX10_PLUS_SHARED_VGPR_COUNT);
462   }
463   PRINT_FIELD(
464       OS, ".amdhsa_exception_fp_ieee_invalid_op", KD,
465       compute_pgm_rsrc2,
466       amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_INVALID_OPERATION);
467   PRINT_FIELD(OS, ".amdhsa_exception_fp_denorm_src", KD,
468               compute_pgm_rsrc2,
469               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_FP_DENORMAL_SOURCE);
470   PRINT_FIELD(
471       OS, ".amdhsa_exception_fp_ieee_div_zero", KD,
472       compute_pgm_rsrc2,
473       amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_DIVISION_BY_ZERO);
474   PRINT_FIELD(OS, ".amdhsa_exception_fp_ieee_overflow", KD,
475               compute_pgm_rsrc2,
476               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_OVERFLOW);
477   PRINT_FIELD(OS, ".amdhsa_exception_fp_ieee_underflow", KD,
478               compute_pgm_rsrc2,
479               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_UNDERFLOW);
480   PRINT_FIELD(OS, ".amdhsa_exception_fp_ieee_inexact", KD,
481               compute_pgm_rsrc2,
482               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_IEEE_754_FP_INEXACT);
483   PRINT_FIELD(OS, ".amdhsa_exception_int_div_zero", KD,
484               compute_pgm_rsrc2,
485               amdhsa::COMPUTE_PGM_RSRC2_ENABLE_EXCEPTION_INT_DIVIDE_BY_ZERO);
486 #undef PRINT_FIELD
487 
488   OS << "\t.end_amdhsa_kernel\n";
489 }
490 
491 //===----------------------------------------------------------------------===//
492 // AMDGPUTargetELFStreamer
493 //===----------------------------------------------------------------------===//
494 
495 AMDGPUTargetELFStreamer::AMDGPUTargetELFStreamer(MCStreamer &S,
496                                                  const MCSubtargetInfo &STI)
497     : AMDGPUTargetStreamer(S), STI(STI), Streamer(S) {}
498 
499 MCELFStreamer &AMDGPUTargetELFStreamer::getStreamer() {
500   return static_cast<MCELFStreamer &>(Streamer);
501 }
502 
503 // A hook for emitting stuff at the end.
504 // We use it for emitting the accumulated PAL metadata as a .note record.
505 // The PAL metadata is reset after it is emitted.
506 void AMDGPUTargetELFStreamer::finish() {
507   MCAssembler &MCA = getStreamer().getAssembler();
508   MCA.setELFHeaderEFlags(getEFlags());
509 
510   std::string Blob;
511   const char *Vendor = getPALMetadata()->getVendor();
512   unsigned Type = getPALMetadata()->getType();
513   getPALMetadata()->toBlob(Type, Blob);
514   if (Blob.empty())
515     return;
516   EmitNote(Vendor, MCConstantExpr::create(Blob.size(), getContext()), Type,
517            [&](MCELFStreamer &OS) { OS.emitBytes(Blob); });
518 
519   // Reset the pal metadata so its data will not affect a compilation that
520   // reuses this object.
521   getPALMetadata()->reset();
522 }
523 
524 void AMDGPUTargetELFStreamer::EmitNote(
525     StringRef Name, const MCExpr *DescSZ, unsigned NoteType,
526     function_ref<void(MCELFStreamer &)> EmitDesc) {
527   auto &S = getStreamer();
528   auto &Context = S.getContext();
529 
530   auto NameSZ = Name.size() + 1;
531 
532   unsigned NoteFlags = 0;
533   // TODO Apparently, this is currently needed for OpenCL as mentioned in
534   // https://reviews.llvm.org/D74995
535   if (STI.getTargetTriple().getOS() == Triple::AMDHSA)
536     NoteFlags = ELF::SHF_ALLOC;
537 
538   S.pushSection();
539   S.switchSection(
540       Context.getELFSection(ElfNote::SectionName, ELF::SHT_NOTE, NoteFlags));
541   S.emitInt32(NameSZ);                                        // namesz
542   S.emitValue(DescSZ, 4);                                     // descz
543   S.emitInt32(NoteType);                                      // type
544   S.emitBytes(Name);                                          // name
545   S.emitValueToAlignment(4, 0, 1, 0);                         // padding 0
546   EmitDesc(S);                                                // desc
547   S.emitValueToAlignment(4, 0, 1, 0);                         // padding 0
548   S.popSection();
549 }
550 
551 unsigned AMDGPUTargetELFStreamer::getEFlags() {
552   switch (STI.getTargetTriple().getArch()) {
553   default:
554     llvm_unreachable("Unsupported Arch");
555   case Triple::r600:
556     return getEFlagsR600();
557   case Triple::amdgcn:
558     return getEFlagsAMDGCN();
559   }
560 }
561 
562 unsigned AMDGPUTargetELFStreamer::getEFlagsR600() {
563   assert(STI.getTargetTriple().getArch() == Triple::r600);
564 
565   return getElfMach(STI.getCPU());
566 }
567 
568 unsigned AMDGPUTargetELFStreamer::getEFlagsAMDGCN() {
569   assert(STI.getTargetTriple().getArch() == Triple::amdgcn);
570 
571   switch (STI.getTargetTriple().getOS()) {
572   default:
573     // TODO: Why are some tests have "mingw" listed as OS?
574     // llvm_unreachable("Unsupported OS");
575   case Triple::UnknownOS:
576     return getEFlagsUnknownOS();
577   case Triple::AMDHSA:
578     return getEFlagsAMDHSA();
579   case Triple::AMDPAL:
580     return getEFlagsAMDPAL();
581   case Triple::Mesa3D:
582     return getEFlagsMesa3D();
583   }
584 }
585 
586 unsigned AMDGPUTargetELFStreamer::getEFlagsUnknownOS() {
587   // TODO: Why are some tests have "mingw" listed as OS?
588   // assert(STI.getTargetTriple().getOS() == Triple::UnknownOS);
589 
590   return getEFlagsV3();
591 }
592 
593 unsigned AMDGPUTargetELFStreamer::getEFlagsAMDHSA() {
594   assert(STI.getTargetTriple().getOS() == Triple::AMDHSA);
595 
596   if (Optional<uint8_t> HsaAbiVer = getHsaAbiVersion(&STI)) {
597     switch (*HsaAbiVer) {
598     case ELF::ELFABIVERSION_AMDGPU_HSA_V2:
599     case ELF::ELFABIVERSION_AMDGPU_HSA_V3:
600       return getEFlagsV3();
601     case ELF::ELFABIVERSION_AMDGPU_HSA_V4:
602     case ELF::ELFABIVERSION_AMDGPU_HSA_V5:
603       return getEFlagsV4();
604     }
605   }
606 
607   llvm_unreachable("HSA OS ABI Version identification must be defined");
608 }
609 
610 unsigned AMDGPUTargetELFStreamer::getEFlagsAMDPAL() {
611   assert(STI.getTargetTriple().getOS() == Triple::AMDPAL);
612 
613   return getEFlagsV3();
614 }
615 
616 unsigned AMDGPUTargetELFStreamer::getEFlagsMesa3D() {
617   assert(STI.getTargetTriple().getOS() == Triple::Mesa3D);
618 
619   return getEFlagsV3();
620 }
621 
622 unsigned AMDGPUTargetELFStreamer::getEFlagsV3() {
623   unsigned EFlagsV3 = 0;
624 
625   // mach.
626   EFlagsV3 |= getElfMach(STI.getCPU());
627 
628   // xnack.
629   if (getTargetID()->isXnackOnOrAny())
630     EFlagsV3 |= ELF::EF_AMDGPU_FEATURE_XNACK_V3;
631   // sramecc.
632   if (getTargetID()->isSramEccOnOrAny())
633     EFlagsV3 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_V3;
634 
635   return EFlagsV3;
636 }
637 
638 unsigned AMDGPUTargetELFStreamer::getEFlagsV4() {
639   unsigned EFlagsV4 = 0;
640 
641   // mach.
642   EFlagsV4 |= getElfMach(STI.getCPU());
643 
644   // xnack.
645   switch (getTargetID()->getXnackSetting()) {
646   case AMDGPU::IsaInfo::TargetIDSetting::Unsupported:
647     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_UNSUPPORTED_V4;
648     break;
649   case AMDGPU::IsaInfo::TargetIDSetting::Any:
650     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_ANY_V4;
651     break;
652   case AMDGPU::IsaInfo::TargetIDSetting::Off:
653     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_OFF_V4;
654     break;
655   case AMDGPU::IsaInfo::TargetIDSetting::On:
656     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_XNACK_ON_V4;
657     break;
658   }
659   // sramecc.
660   switch (getTargetID()->getSramEccSetting()) {
661   case AMDGPU::IsaInfo::TargetIDSetting::Unsupported:
662     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_UNSUPPORTED_V4;
663     break;
664   case AMDGPU::IsaInfo::TargetIDSetting::Any:
665     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_ANY_V4;
666     break;
667   case AMDGPU::IsaInfo::TargetIDSetting::Off:
668     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_OFF_V4;
669     break;
670   case AMDGPU::IsaInfo::TargetIDSetting::On:
671     EFlagsV4 |= ELF::EF_AMDGPU_FEATURE_SRAMECC_ON_V4;
672     break;
673   }
674 
675   return EFlagsV4;
676 }
677 
678 void AMDGPUTargetELFStreamer::EmitDirectiveAMDGCNTarget() {}
679 
680 void AMDGPUTargetELFStreamer::EmitDirectiveHSACodeObjectVersion(
681     uint32_t Major, uint32_t Minor) {
682 
683   EmitNote(ElfNote::NoteNameV2, MCConstantExpr::create(8, getContext()),
684            ELF::NT_AMD_HSA_CODE_OBJECT_VERSION, [&](MCELFStreamer &OS) {
685              OS.emitInt32(Major);
686              OS.emitInt32(Minor);
687            });
688 }
689 
690 void
691 AMDGPUTargetELFStreamer::EmitDirectiveHSACodeObjectISAV2(uint32_t Major,
692                                                          uint32_t Minor,
693                                                          uint32_t Stepping,
694                                                          StringRef VendorName,
695                                                          StringRef ArchName) {
696   uint16_t VendorNameSize = VendorName.size() + 1;
697   uint16_t ArchNameSize = ArchName.size() + 1;
698 
699   unsigned DescSZ = sizeof(VendorNameSize) + sizeof(ArchNameSize) +
700     sizeof(Major) + sizeof(Minor) + sizeof(Stepping) +
701     VendorNameSize + ArchNameSize;
702 
703   convertIsaVersionV2(Major, Minor, Stepping, TargetID->isSramEccOnOrAny(), TargetID->isXnackOnOrAny());
704   EmitNote(ElfNote::NoteNameV2, MCConstantExpr::create(DescSZ, getContext()),
705            ELF::NT_AMD_HSA_ISA_VERSION, [&](MCELFStreamer &OS) {
706              OS.emitInt16(VendorNameSize);
707              OS.emitInt16(ArchNameSize);
708              OS.emitInt32(Major);
709              OS.emitInt32(Minor);
710              OS.emitInt32(Stepping);
711              OS.emitBytes(VendorName);
712              OS.emitInt8(0); // NULL terminate VendorName
713              OS.emitBytes(ArchName);
714              OS.emitInt8(0); // NULL terminate ArchName
715            });
716 }
717 
718 void
719 AMDGPUTargetELFStreamer::EmitAMDKernelCodeT(const amd_kernel_code_t &Header) {
720 
721   MCStreamer &OS = getStreamer();
722   OS.pushSection();
723   OS.emitBytes(StringRef((const char*)&Header, sizeof(Header)));
724   OS.popSection();
725 }
726 
727 void AMDGPUTargetELFStreamer::EmitAMDGPUSymbolType(StringRef SymbolName,
728                                                    unsigned Type) {
729   MCSymbolELF *Symbol = cast<MCSymbolELF>(
730       getStreamer().getContext().getOrCreateSymbol(SymbolName));
731   Symbol->setType(Type);
732 }
733 
734 void AMDGPUTargetELFStreamer::emitAMDGPULDS(MCSymbol *Symbol, unsigned Size,
735                                             Align Alignment) {
736   MCSymbolELF *SymbolELF = cast<MCSymbolELF>(Symbol);
737   SymbolELF->setType(ELF::STT_OBJECT);
738 
739   if (!SymbolELF->isBindingSet()) {
740     SymbolELF->setBinding(ELF::STB_GLOBAL);
741     SymbolELF->setExternal(true);
742   }
743 
744   if (SymbolELF->declareCommon(Size, Alignment.value(), true)) {
745     report_fatal_error("Symbol: " + Symbol->getName() +
746                        " redeclared as different type");
747   }
748 
749   SymbolELF->setIndex(ELF::SHN_AMDGPU_LDS);
750   SymbolELF->setSize(MCConstantExpr::create(Size, getContext()));
751 }
752 
753 bool AMDGPUTargetELFStreamer::EmitISAVersion() {
754   // Create two labels to mark the beginning and end of the desc field
755   // and a MCExpr to calculate the size of the desc field.
756   auto &Context = getContext();
757   auto *DescBegin = Context.createTempSymbol();
758   auto *DescEnd = Context.createTempSymbol();
759   auto *DescSZ = MCBinaryExpr::createSub(
760     MCSymbolRefExpr::create(DescEnd, Context),
761     MCSymbolRefExpr::create(DescBegin, Context), Context);
762 
763   EmitNote(ElfNote::NoteNameV2, DescSZ, ELF::NT_AMD_HSA_ISA_NAME,
764            [&](MCELFStreamer &OS) {
765              OS.emitLabel(DescBegin);
766              OS.emitBytes(getTargetID()->toString());
767              OS.emitLabel(DescEnd);
768            });
769   return true;
770 }
771 
772 bool AMDGPUTargetELFStreamer::EmitHSAMetadata(msgpack::Document &HSAMetadataDoc,
773                                               bool Strict) {
774   HSAMD::V3::MetadataVerifier Verifier(Strict);
775   if (!Verifier.verify(HSAMetadataDoc.getRoot()))
776     return false;
777 
778   std::string HSAMetadataString;
779   HSAMetadataDoc.writeToBlob(HSAMetadataString);
780 
781   // Create two labels to mark the beginning and end of the desc field
782   // and a MCExpr to calculate the size of the desc field.
783   auto &Context = getContext();
784   auto *DescBegin = Context.createTempSymbol();
785   auto *DescEnd = Context.createTempSymbol();
786   auto *DescSZ = MCBinaryExpr::createSub(
787       MCSymbolRefExpr::create(DescEnd, Context),
788       MCSymbolRefExpr::create(DescBegin, Context), Context);
789 
790   EmitNote(ElfNote::NoteNameV3, DescSZ, ELF::NT_AMDGPU_METADATA,
791            [&](MCELFStreamer &OS) {
792              OS.emitLabel(DescBegin);
793              OS.emitBytes(HSAMetadataString);
794              OS.emitLabel(DescEnd);
795            });
796   return true;
797 }
798 
799 bool AMDGPUTargetELFStreamer::EmitHSAMetadata(
800     const AMDGPU::HSAMD::Metadata &HSAMetadata) {
801   std::string HSAMetadataString;
802   if (HSAMD::toString(HSAMetadata, HSAMetadataString))
803     return false;
804 
805   // Create two labels to mark the beginning and end of the desc field
806   // and a MCExpr to calculate the size of the desc field.
807   auto &Context = getContext();
808   auto *DescBegin = Context.createTempSymbol();
809   auto *DescEnd = Context.createTempSymbol();
810   auto *DescSZ = MCBinaryExpr::createSub(
811     MCSymbolRefExpr::create(DescEnd, Context),
812     MCSymbolRefExpr::create(DescBegin, Context), Context);
813 
814   EmitNote(ElfNote::NoteNameV2, DescSZ, ELF::NT_AMD_HSA_METADATA,
815            [&](MCELFStreamer &OS) {
816              OS.emitLabel(DescBegin);
817              OS.emitBytes(HSAMetadataString);
818              OS.emitLabel(DescEnd);
819            });
820   return true;
821 }
822 
823 bool AMDGPUTargetELFStreamer::EmitCodeEnd(const MCSubtargetInfo &STI) {
824   const uint32_t Encoded_s_code_end = 0xbf9f0000;
825   const uint32_t Encoded_s_nop = 0xbf800000;
826   uint32_t Encoded_pad = Encoded_s_code_end;
827 
828   // Instruction cache line size in bytes.
829   const unsigned Log2CacheLineSize = AMDGPU::isGFX11Plus(STI) ? 7 : 6;
830   const unsigned CacheLineSize = 1u << Log2CacheLineSize;
831 
832   // Extra padding amount in bytes to support prefetch mode 3.
833   unsigned FillSize = 3 * CacheLineSize;
834 
835   if (AMDGPU::isGFX90A(STI)) {
836     Encoded_pad = Encoded_s_nop;
837     FillSize = 16 * CacheLineSize;
838   }
839 
840   MCStreamer &OS = getStreamer();
841   OS.pushSection();
842   OS.emitValueToAlignment(CacheLineSize, Encoded_pad, 4);
843   for (unsigned I = 0; I < FillSize; I += 4)
844     OS.emitInt32(Encoded_pad);
845   OS.popSection();
846   return true;
847 }
848 
849 void AMDGPUTargetELFStreamer::EmitAmdhsaKernelDescriptor(
850     const MCSubtargetInfo &STI, StringRef KernelName,
851     const amdhsa::kernel_descriptor_t &KernelDescriptor, uint64_t NextVGPR,
852     uint64_t NextSGPR, bool ReserveVCC, bool ReserveFlatScr) {
853   auto &Streamer = getStreamer();
854   auto &Context = Streamer.getContext();
855 
856   MCSymbolELF *KernelCodeSymbol = cast<MCSymbolELF>(
857       Context.getOrCreateSymbol(Twine(KernelName)));
858   MCSymbolELF *KernelDescriptorSymbol = cast<MCSymbolELF>(
859       Context.getOrCreateSymbol(Twine(KernelName) + Twine(".kd")));
860 
861   // Copy kernel descriptor symbol's binding, other and visibility from the
862   // kernel code symbol.
863   KernelDescriptorSymbol->setBinding(KernelCodeSymbol->getBinding());
864   KernelDescriptorSymbol->setOther(KernelCodeSymbol->getOther());
865   KernelDescriptorSymbol->setVisibility(KernelCodeSymbol->getVisibility());
866   // Kernel descriptor symbol's type and size are fixed.
867   KernelDescriptorSymbol->setType(ELF::STT_OBJECT);
868   KernelDescriptorSymbol->setSize(
869       MCConstantExpr::create(sizeof(KernelDescriptor), Context));
870 
871   // The visibility of the kernel code symbol must be protected or less to allow
872   // static relocations from the kernel descriptor to be used.
873   if (KernelCodeSymbol->getVisibility() == ELF::STV_DEFAULT)
874     KernelCodeSymbol->setVisibility(ELF::STV_PROTECTED);
875 
876   Streamer.emitLabel(KernelDescriptorSymbol);
877   Streamer.emitInt32(KernelDescriptor.group_segment_fixed_size);
878   Streamer.emitInt32(KernelDescriptor.private_segment_fixed_size);
879   Streamer.emitInt32(KernelDescriptor.kernarg_size);
880 
881   for (uint8_t Res : KernelDescriptor.reserved0)
882     Streamer.emitInt8(Res);
883 
884   // FIXME: Remove the use of VK_AMDGPU_REL64 in the expression below. The
885   // expression being created is:
886   //   (start of kernel code) - (start of kernel descriptor)
887   // It implies R_AMDGPU_REL64, but ends up being R_AMDGPU_ABS64.
888   Streamer.emitValue(MCBinaryExpr::createSub(
889       MCSymbolRefExpr::create(
890           KernelCodeSymbol, MCSymbolRefExpr::VK_AMDGPU_REL64, Context),
891       MCSymbolRefExpr::create(
892           KernelDescriptorSymbol, MCSymbolRefExpr::VK_None, Context),
893       Context),
894       sizeof(KernelDescriptor.kernel_code_entry_byte_offset));
895   for (uint8_t Res : KernelDescriptor.reserved1)
896     Streamer.emitInt8(Res);
897   Streamer.emitInt32(KernelDescriptor.compute_pgm_rsrc3);
898   Streamer.emitInt32(KernelDescriptor.compute_pgm_rsrc1);
899   Streamer.emitInt32(KernelDescriptor.compute_pgm_rsrc2);
900   Streamer.emitInt16(KernelDescriptor.kernel_code_properties);
901   for (uint8_t Res : KernelDescriptor.reserved2)
902     Streamer.emitInt8(Res);
903 }
904