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//===-- SILowerI1Copies.cpp - Lower I1 Copies -----------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
/// i1 values are usually inserted by the CFG Structurize pass and they are
/// unique in that they can be copied from VALU to SALU registers.
/// This is not possible for any other value type. Since there are no
/// MOV instructions for i1, we to use V_CMP_* and V_CNDMASK to move the i1.
///
//===----------------------------------------------------------------------===//
//
#define DEBUG_TYPE "si-i1-copies"
#include "AMDGPU.h"
#include "AMDGPUSubtarget.h"
#include "SIInstrInfo.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "Utils/AMDGPULaneDominator.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
namespace {
class SILowerI1Copies : public MachineFunctionPass {
public:
static char ID;
public:
SILowerI1Copies() : MachineFunctionPass(ID) {
initializeSILowerI1CopiesPass(*PassRegistry::getPassRegistry());
}
bool runOnMachineFunction(MachineFunction &MF) override;
StringRef getPassName() const override { return "SI Lower i1 Copies"; }
void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.setPreservesCFG();
MachineFunctionPass::getAnalysisUsage(AU);
}
};
} // End anonymous namespace.
INITIALIZE_PASS(SILowerI1Copies, DEBUG_TYPE,
"SI Lower i1 Copies", false, false)
char SILowerI1Copies::ID = 0;
char &llvm::SILowerI1CopiesID = SILowerI1Copies::ID;
FunctionPass *llvm::createSILowerI1CopiesPass() {
return new SILowerI1Copies();
}
bool SILowerI1Copies::runOnMachineFunction(MachineFunction &MF) {
MachineRegisterInfo &MRI = MF.getRegInfo();
const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
const SIInstrInfo *TII = ST.getInstrInfo();
const TargetRegisterInfo *TRI = &TII->getRegisterInfo();
std::vector<unsigned> I1Defs;
for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
BI != BE; ++BI) {
MachineBasicBlock &MBB = *BI;
MachineBasicBlock::iterator I, Next;
for (I = MBB.begin(); I != MBB.end(); I = Next) {
Next = std::next(I);
MachineInstr &MI = *I;
if (MI.getOpcode() == AMDGPU::IMPLICIT_DEF) {
unsigned Reg = MI.getOperand(0).getReg();
const TargetRegisterClass *RC = MRI.getRegClass(Reg);
if (RC == &AMDGPU::VReg_1RegClass)
MRI.setRegClass(Reg, &AMDGPU::SReg_64RegClass);
continue;
}
if (MI.getOpcode() != AMDGPU::COPY)
continue;
const MachineOperand &Dst = MI.getOperand(0);
const MachineOperand &Src = MI.getOperand(1);
if (!TargetRegisterInfo::isVirtualRegister(Src.getReg()) ||
!TargetRegisterInfo::isVirtualRegister(Dst.getReg()))
continue;
const TargetRegisterClass *DstRC = MRI.getRegClass(Dst.getReg());
const TargetRegisterClass *SrcRC = MRI.getRegClass(Src.getReg());
DebugLoc DL = MI.getDebugLoc();
MachineInstr *DefInst = MRI.getUniqueVRegDef(Src.getReg());
if (DstRC == &AMDGPU::VReg_1RegClass &&
TRI->getCommonSubClass(SrcRC, &AMDGPU::SGPR_64RegClass)) {
I1Defs.push_back(Dst.getReg());
if (DefInst->getOpcode() == AMDGPU::S_MOV_B64) {
if (DefInst->getOperand(1).isImm()) {
I1Defs.push_back(Dst.getReg());
int64_t Val = DefInst->getOperand(1).getImm();
assert(Val == 0 || Val == -1);
BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_MOV_B32_e32))
.add(Dst)
.addImm(Val);
MI.eraseFromParent();
continue;
}
}
unsigned int TmpSrc = MRI.createVirtualRegister(&AMDGPU::SReg_64_XEXECRegClass);
BuildMI(MBB, &MI, DL, TII->get(AMDGPU::COPY), TmpSrc)
.add(Src);
BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CNDMASK_B32_e64))
.add(Dst)
.addImm(0)
.addImm(-1)
.addReg(TmpSrc);
MI.eraseFromParent();
} else if (TRI->getCommonSubClass(DstRC, &AMDGPU::SGPR_64RegClass) &&
SrcRC == &AMDGPU::VReg_1RegClass) {
if (DefInst->getOpcode() == AMDGPU::V_CNDMASK_B32_e64 &&
DefInst->getOperand(1).isImm() && DefInst->getOperand(2).isImm() &&
DefInst->getOperand(1).getImm() == 0 &&
DefInst->getOperand(2).getImm() != 0 &&
DefInst->getOperand(3).isReg() &&
TargetRegisterInfo::isVirtualRegister(
DefInst->getOperand(3).getReg()) &&
TRI->getCommonSubClass(
MRI.getRegClass(DefInst->getOperand(3).getReg()),
&AMDGPU::SGPR_64RegClass) &&
AMDGPU::laneDominates(DefInst->getParent(), &MBB)) {
BuildMI(MBB, &MI, DL, TII->get(AMDGPU::S_AND_B64))
.add(Dst)
.addReg(AMDGPU::EXEC)
.add(DefInst->getOperand(3));
} else {
BuildMI(MBB, &MI, DL, TII->get(AMDGPU::V_CMP_NE_U32_e64))
.add(Dst)
.add(Src)
.addImm(0);
}
MI.eraseFromParent();
}
}
}
for (unsigned Reg : I1Defs)
MRI.setRegClass(Reg, &AMDGPU::VGPR_32RegClass);
return false;
}