1 //===- ARCISelDAGToDAG.cpp - ARC dag to dag inst selector -------*- C++ -*-===//
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 defines an instruction selector for the ARC target.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "ARC.h"
14 #include "ARCTargetMachine.h"
15 #include "llvm/CodeGen/MachineFrameInfo.h"
16 #include "llvm/CodeGen/MachineFunction.h"
17 #include "llvm/CodeGen/MachineInstrBuilder.h"
18 #include "llvm/CodeGen/MachineRegisterInfo.h"
19 #include "llvm/CodeGen/SelectionDAG.h"
20 #include "llvm/CodeGen/SelectionDAGISel.h"
21 #include "llvm/CodeGen/TargetLowering.h"
22 #include "llvm/IR/CallingConv.h"
23 #include "llvm/IR/Constants.h"
24 #include "llvm/IR/DerivedTypes.h"
25 #include "llvm/IR/Function.h"
26 #include "llvm/IR/Intrinsics.h"
27 #include "llvm/IR/LLVMContext.h"
28 #include "llvm/Support/Compiler.h"
29 #include "llvm/Support/Debug.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/raw_ostream.h"
32
33 using namespace llvm;
34
35 #define DEBUG_TYPE "arc-isel"
36 #define PASS_NAME "ARC DAG->DAG Pattern Instruction Selection"
37
38 /// ARCDAGToDAGISel - ARC specific code to select ARC machine
39 /// instructions for SelectionDAG operations.
40 namespace {
41
42 class ARCDAGToDAGISel : public SelectionDAGISel {
43 public:
44 static char ID;
45
46 ARCDAGToDAGISel() = delete;
47
ARCDAGToDAGISel(ARCTargetMachine & TM,CodeGenOptLevel OptLevel)48 ARCDAGToDAGISel(ARCTargetMachine &TM, CodeGenOptLevel OptLevel)
49 : SelectionDAGISel(ID, TM, OptLevel) {}
50
51 void Select(SDNode *N) override;
52
53 // Complex Pattern Selectors.
54 bool SelectFrameADDR_ri(SDValue Addr, SDValue &Base, SDValue &Offset);
55 bool SelectAddrModeS9(SDValue Addr, SDValue &Base, SDValue &Offset);
56 bool SelectAddrModeImm(SDValue Addr, SDValue &Base, SDValue &Offset);
57 bool SelectAddrModeFar(SDValue Addr, SDValue &Base, SDValue &Offset);
58
59 // Include the pieces autogenerated from the target description.
60 #include "ARCGenDAGISel.inc"
61 };
62
63 char ARCDAGToDAGISel::ID;
64
65 } // end anonymous namespace
66
INITIALIZE_PASS(ARCDAGToDAGISel,DEBUG_TYPE,PASS_NAME,false,false)67 INITIALIZE_PASS(ARCDAGToDAGISel, DEBUG_TYPE, PASS_NAME, false, false)
68
69 /// This pass converts a legalized DAG into a ARC-specific DAG, ready for
70 /// instruction scheduling.
71 FunctionPass *llvm::createARCISelDag(ARCTargetMachine &TM,
72 CodeGenOptLevel OptLevel) {
73 return new ARCDAGToDAGISel(TM, OptLevel);
74 }
75
SelectAddrModeImm(SDValue Addr,SDValue & Base,SDValue & Offset)76 bool ARCDAGToDAGISel::SelectAddrModeImm(SDValue Addr, SDValue &Base,
77 SDValue &Offset) {
78 if (Addr.getOpcode() == ARCISD::GAWRAPPER) {
79 Base = Addr.getOperand(0);
80 Offset = CurDAG->getTargetConstant(0, SDLoc(Addr), MVT::i32);
81 return true;
82 }
83 return false;
84 }
85
SelectAddrModeS9(SDValue Addr,SDValue & Base,SDValue & Offset)86 bool ARCDAGToDAGISel::SelectAddrModeS9(SDValue Addr, SDValue &Base,
87 SDValue &Offset) {
88 if (Addr.getOpcode() == ARCISD::GAWRAPPER) {
89 return false;
90 }
91
92 if (Addr.getOpcode() != ISD::ADD && Addr.getOpcode() != ISD::SUB &&
93 !CurDAG->isBaseWithConstantOffset(Addr)) {
94 if (Addr.getOpcode() == ISD::FrameIndex) {
95 // Match frame index.
96 int FI = cast<FrameIndexSDNode>(Addr)->getIndex();
97 Base = CurDAG->getTargetFrameIndex(
98 FI, TLI->getPointerTy(CurDAG->getDataLayout()));
99 } else {
100 Base = Addr;
101 }
102 Offset = CurDAG->getTargetConstant(0, SDLoc(Addr), MVT::i32);
103 return true;
104 }
105
106 if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
107 int32_t RHSC = RHS->getSExtValue();
108 if (Addr.getOpcode() == ISD::SUB)
109 RHSC = -RHSC;
110
111 // Do we need more than 9 bits to encode?
112 if (!isInt<9>(RHSC))
113 return false;
114 Base = Addr.getOperand(0);
115 if (Base.getOpcode() == ISD::FrameIndex) {
116 int FI = cast<FrameIndexSDNode>(Base)->getIndex();
117 Base = CurDAG->getTargetFrameIndex(
118 FI, TLI->getPointerTy(CurDAG->getDataLayout()));
119 }
120 Offset = CurDAG->getTargetConstant(RHSC, SDLoc(Addr), MVT::i32);
121 return true;
122 }
123 Base = Addr;
124 Offset = CurDAG->getTargetConstant(0, SDLoc(Addr), MVT::i32);
125 return true;
126 }
127
SelectAddrModeFar(SDValue Addr,SDValue & Base,SDValue & Offset)128 bool ARCDAGToDAGISel::SelectAddrModeFar(SDValue Addr, SDValue &Base,
129 SDValue &Offset) {
130 if (SelectAddrModeS9(Addr, Base, Offset))
131 return false;
132 if (Addr.getOpcode() == ARCISD::GAWRAPPER) {
133 return false;
134 }
135 if (ConstantSDNode *RHS = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) {
136 int32_t RHSC = RHS->getSExtValue();
137 if (Addr.getOpcode() == ISD::SUB)
138 RHSC = -RHSC;
139 Base = Addr.getOperand(0);
140 Offset = CurDAG->getTargetConstant(RHSC, SDLoc(Addr), MVT::i32);
141 return true;
142 }
143 return false;
144 }
145
146 // Is this a legal frame index addressing expression.
SelectFrameADDR_ri(SDValue Addr,SDValue & Base,SDValue & Offset)147 bool ARCDAGToDAGISel::SelectFrameADDR_ri(SDValue Addr, SDValue &Base,
148 SDValue &Offset) {
149 FrameIndexSDNode *FIN = nullptr;
150 if ((FIN = dyn_cast<FrameIndexSDNode>(Addr))) {
151 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
152 Offset = CurDAG->getTargetConstant(0, SDLoc(Addr), MVT::i32);
153 return true;
154 }
155 if (Addr.getOpcode() == ISD::ADD) {
156 ConstantSDNode *CN = nullptr;
157 if ((FIN = dyn_cast<FrameIndexSDNode>(Addr.getOperand(0))) &&
158 (CN = dyn_cast<ConstantSDNode>(Addr.getOperand(1))) &&
159 (CN->getSExtValue() % 4 == 0 && CN->getSExtValue() >= 0)) {
160 // Constant positive word offset from frame index
161 Base = CurDAG->getTargetFrameIndex(FIN->getIndex(), MVT::i32);
162 Offset =
163 CurDAG->getTargetConstant(CN->getSExtValue(), SDLoc(Addr), MVT::i32);
164 return true;
165 }
166 }
167 return false;
168 }
169
Select(SDNode * N)170 void ARCDAGToDAGISel::Select(SDNode *N) {
171 switch (N->getOpcode()) {
172 case ISD::Constant: {
173 uint64_t CVal = N->getAsZExtVal();
174 ReplaceNode(N, CurDAG->getMachineNode(
175 isInt<12>(CVal) ? ARC::MOV_rs12 : ARC::MOV_rlimm,
176 SDLoc(N), MVT::i32,
177 CurDAG->getTargetConstant(CVal, SDLoc(N), MVT::i32)));
178 return;
179 }
180 }
181 SelectCode(N);
182 }
183