1 //===-- SILowerI1Copies.cpp - Lower I1 Copies -----------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 /// i1 values are usually inserted by the CFG Structurize pass and they are
9 /// unique in that they can be copied from VALU to SALU registers.
10 /// This is not possible for any other value type. Since there are no
11 /// MOV instructions for i1, we to use V_CMP_* and V_CNDMASK to move the i1.
13 //===----------------------------------------------------------------------===//
16 #define DEBUG_TYPE "si-i1-copies"
18 #include "AMDGPUSubtarget.h"
19 #include "SIInstrInfo.h"
20 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
21 #include "Utils/AMDGPULaneDominator.h"
22 #include "llvm/CodeGen/LiveIntervals.h"
23 #include "llvm/CodeGen/MachineFunctionPass.h"
24 #include "llvm/CodeGen/MachineInstrBuilder.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/IR/Function.h"
27 #include "llvm/IR/LLVMContext.h"
28 #include "llvm/Support/Debug.h"
29 #include "llvm/Target/TargetMachine.h"
35 class SILowerI1Copies : public MachineFunctionPass {
40 SILowerI1Copies() : MachineFunctionPass(ID) {
41 initializeSILowerI1CopiesPass(*PassRegistry::getPassRegistry());
44 bool runOnMachineFunction(MachineFunction &MF) override;
46 StringRef getPassName() const override { return "SI Lower i1 Copies"; }
48 void getAnalysisUsage(AnalysisUsage &AU) const override {
50 MachineFunctionPass::getAnalysisUsage(AU);
54 } // End anonymous namespace.
56 INITIALIZE_PASS(SILowerI1Copies, DEBUG_TYPE,
57 "SI Lower i1 Copies", false, false)
59 char SILowerI1Copies::ID = 0;
61 char &llvm::SILowerI1CopiesID = SILowerI1Copies::ID;
63 FunctionPass *llvm::createSILowerI1CopiesPass() {
64 return new SILowerI1Copies();
67 bool SILowerI1Copies::runOnMachineFunction(MachineFunction &MF) {
68 MachineRegisterInfo &MRI = MF.getRegInfo();
69 const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
70 const SIInstrInfo *TII = ST.getInstrInfo();
71 const TargetRegisterInfo *TRI = &TII->getRegisterInfo();
73 std::vector<unsigned> I1Defs;
75 for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
78 MachineBasicBlock &MBB = *BI;
79 MachineBasicBlock::iterator I, Next;
80 for (I = MBB.begin(); I != MBB.end(); I = Next) {
82 MachineInstr &MI = *I;
84 if (MI.getOpcode() == AMDGPU::IMPLICIT_DEF) {
85 unsigned Reg = MI.getOperand(0).getReg();
86 const TargetRegisterClass *RC = MRI.getRegClass(Reg);
87 if (RC == &AMDGPU::VReg_1RegClass)
88 MRI.setRegClass(Reg, &AMDGPU::SReg_64RegClass);
92 if (MI.getOpcode() != AMDGPU::COPY)
95 const MachineOperand &Dst = MI.getOperand(0);
96 const MachineOperand &Src = MI.getOperand(1);
98 if (!TargetRegisterInfo::isVirtualRegister(Src.getReg()) ||
99 !TargetRegisterInfo::isVirtualRegister(Dst.getReg()))
102 const TargetRegisterClass *DstRC = MRI.getRegClass(Dst.getReg());
103 const TargetRegisterClass *SrcRC = MRI.getRegClass(Src.getReg());
105 DebugLoc DL = MI.getDebugLoc();
106 MachineInstr *DefInst = MRI.getUniqueVRegDef(Src.getReg());
107 if (DstRC == &AMDGPU::VReg_1RegClass &&
108 TRI->getCommonSubClass(SrcRC, &AMDGPU::SGPR_64RegClass)) {
109 I1Defs.push_back(Dst.getReg());
111 if (DefInst->getOpcode() == AMDGPU::S_MOV_B64) {
112 if (DefInst->getOperand(1).isImm()) {
113 I1Defs.push_back(Dst.getReg());
115 int64_t Val = DefInst->getOperand(1).getImm();
116 assert(Val == 0 || Val == -1);
118 BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_MOV_B32_e32))
121 MI.eraseFromParent();
126 unsigned int TmpSrc = MRI.createVirtualRegister(&AMDGPU::SReg_64_XEXECRegClass);
127 BuildMI(MBB, &MI, DL, TII->get(AMDGPU::COPY), TmpSrc)
129 BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CNDMASK_B32_e64))
134 MI.eraseFromParent();
135 } else if (TRI->getCommonSubClass(DstRC, &AMDGPU::SGPR_64RegClass) &&
136 SrcRC == &AMDGPU::VReg_1RegClass) {
137 if (DefInst->getOpcode() == AMDGPU::V_CNDMASK_B32_e64 &&
138 DefInst->getOperand(1).isImm() && DefInst->getOperand(2).isImm() &&
139 DefInst->getOperand(1).getImm() == 0 &&
140 DefInst->getOperand(2).getImm() != 0 &&
141 DefInst->getOperand(3).isReg() &&
142 TargetRegisterInfo::isVirtualRegister(
143 DefInst->getOperand(3).getReg()) &&
144 TRI->getCommonSubClass(
145 MRI.getRegClass(DefInst->getOperand(3).getReg()),
146 &AMDGPU::SGPR_64RegClass) &&
147 AMDGPU::laneDominates(DefInst->getParent(), &MBB)) {
148 BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_AND_B64))
150 .addReg(AMDGPU::EXEC)
151 .add(DefInst->getOperand(3));
153 BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CMP_NE_U32_e64))
158 MI.eraseFromParent();
163 for (unsigned Reg : I1Defs)
164 MRI.setRegClass(Reg, &AMDGPU::VGPR_32RegClass);