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//===-- R600ClauseMergePass - Merge consecutive CF_ALU -------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
/// \file
/// R600EmitClauseMarker pass emits CFAlu instruction in a conservative maneer.
/// This pass is merging consecutive CFAlus where applicable.
/// It needs to be called after IfCvt for best results.
//===----------------------------------------------------------------------===//
#include "AMDGPU.h"
#include "AMDGPUSubtarget.h"
#include "R600Defines.h"
#include "R600InstrInfo.h"
#include "R600MachineFunctionInfo.h"
#include "R600RegisterInfo.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
#define DEBUG_TYPE "r600mergeclause"
namespace {
static bool isCFAlu(const MachineInstr &MI) {
switch (MI.getOpcode()) {
case R600::CF_ALU:
case R600::CF_ALU_PUSH_BEFORE:
return true;
default:
return false;
}
}
class R600ClauseMergePass : public MachineFunctionPass {
private:
const R600InstrInfo *TII;
unsigned getCFAluSize(const MachineInstr &MI) const;
bool isCFAluEnabled(const MachineInstr &MI) const;
/// IfCvt pass can generate "disabled" ALU clause marker that need to be
/// removed and their content affected to the previous alu clause.
/// This function parse instructions after CFAlu until it find a disabled
/// CFAlu and merge the content, or an enabled CFAlu.
void cleanPotentialDisabledCFAlu(MachineInstr &CFAlu) const;
/// Check whether LatrCFAlu can be merged into RootCFAlu and do it if
/// it is the case.
bool mergeIfPossible(MachineInstr &RootCFAlu,
const MachineInstr &LatrCFAlu) const;
public:
static char ID;
R600ClauseMergePass() : MachineFunctionPass(ID) { }
bool runOnMachineFunction(MachineFunction &MF) override;
StringRef getPassName() const override;
};
} // end anonymous namespace
INITIALIZE_PASS_BEGIN(R600ClauseMergePass, DEBUG_TYPE,
"R600 Clause Merge", false, false)
INITIALIZE_PASS_END(R600ClauseMergePass, DEBUG_TYPE,
"R600 Clause Merge", false, false)
char R600ClauseMergePass::ID = 0;
char &llvm::R600ClauseMergePassID = R600ClauseMergePass::ID;
unsigned R600ClauseMergePass::getCFAluSize(const MachineInstr &MI) const {
assert(isCFAlu(MI));
return MI
.getOperand(TII->getOperandIdx(MI.getOpcode(), R600::OpName::COUNT))
.getImm();
}
bool R600ClauseMergePass::isCFAluEnabled(const MachineInstr &MI) const {
assert(isCFAlu(MI));
return MI
.getOperand(TII->getOperandIdx(MI.getOpcode(), R600::OpName::Enabled))
.getImm();
}
void R600ClauseMergePass::cleanPotentialDisabledCFAlu(
MachineInstr &CFAlu) const {
int CntIdx = TII->getOperandIdx(R600::CF_ALU, R600::OpName::COUNT);
MachineBasicBlock::iterator I = CFAlu, E = CFAlu.getParent()->end();
I++;
do {
while (I != E && !isCFAlu(*I))
I++;
if (I == E)
return;
MachineInstr &MI = *I++;
if (isCFAluEnabled(MI))
break;
CFAlu.getOperand(CntIdx).setImm(getCFAluSize(CFAlu) + getCFAluSize(MI));
MI.eraseFromParent();
} while (I != E);
}
bool R600ClauseMergePass::mergeIfPossible(MachineInstr &RootCFAlu,
const MachineInstr &LatrCFAlu) const {
assert(isCFAlu(RootCFAlu) && isCFAlu(LatrCFAlu));
int CntIdx = TII->getOperandIdx(R600::CF_ALU, R600::OpName::COUNT);
unsigned RootInstCount = getCFAluSize(RootCFAlu),
LaterInstCount = getCFAluSize(LatrCFAlu);
unsigned CumuledInsts = RootInstCount + LaterInstCount;
if (CumuledInsts >= TII->getMaxAlusPerClause()) {
LLVM_DEBUG(dbgs() << "Excess inst counts\n");
return false;
}
if (RootCFAlu.getOpcode() == R600::CF_ALU_PUSH_BEFORE)
return false;
// Is KCache Bank 0 compatible ?
int Mode0Idx =
TII->getOperandIdx(R600::CF_ALU, R600::OpName::KCACHE_MODE0);
int KBank0Idx =
TII->getOperandIdx(R600::CF_ALU, R600::OpName::KCACHE_BANK0);
int KBank0LineIdx =
TII->getOperandIdx(R600::CF_ALU, R600::OpName::KCACHE_ADDR0);
if (LatrCFAlu.getOperand(Mode0Idx).getImm() &&
RootCFAlu.getOperand(Mode0Idx).getImm() &&
(LatrCFAlu.getOperand(KBank0Idx).getImm() !=
RootCFAlu.getOperand(KBank0Idx).getImm() ||
LatrCFAlu.getOperand(KBank0LineIdx).getImm() !=
RootCFAlu.getOperand(KBank0LineIdx).getImm())) {
LLVM_DEBUG(dbgs() << "Wrong KC0\n");
return false;
}
// Is KCache Bank 1 compatible ?
int Mode1Idx =
TII->getOperandIdx(R600::CF_ALU, R600::OpName::KCACHE_MODE1);
int KBank1Idx =
TII->getOperandIdx(R600::CF_ALU, R600::OpName::KCACHE_BANK1);
int KBank1LineIdx =
TII->getOperandIdx(R600::CF_ALU, R600::OpName::KCACHE_ADDR1);
if (LatrCFAlu.getOperand(Mode1Idx).getImm() &&
RootCFAlu.getOperand(Mode1Idx).getImm() &&
(LatrCFAlu.getOperand(KBank1Idx).getImm() !=
RootCFAlu.getOperand(KBank1Idx).getImm() ||
LatrCFAlu.getOperand(KBank1LineIdx).getImm() !=
RootCFAlu.getOperand(KBank1LineIdx).getImm())) {
LLVM_DEBUG(dbgs() << "Wrong KC0\n");
return false;
}
if (LatrCFAlu.getOperand(Mode0Idx).getImm()) {
RootCFAlu.getOperand(Mode0Idx).setImm(
LatrCFAlu.getOperand(Mode0Idx).getImm());
RootCFAlu.getOperand(KBank0Idx).setImm(
LatrCFAlu.getOperand(KBank0Idx).getImm());
RootCFAlu.getOperand(KBank0LineIdx)
.setImm(LatrCFAlu.getOperand(KBank0LineIdx).getImm());
}
if (LatrCFAlu.getOperand(Mode1Idx).getImm()) {
RootCFAlu.getOperand(Mode1Idx).setImm(
LatrCFAlu.getOperand(Mode1Idx).getImm());
RootCFAlu.getOperand(KBank1Idx).setImm(
LatrCFAlu.getOperand(KBank1Idx).getImm());
RootCFAlu.getOperand(KBank1LineIdx)
.setImm(LatrCFAlu.getOperand(KBank1LineIdx).getImm());
}
RootCFAlu.getOperand(CntIdx).setImm(CumuledInsts);
RootCFAlu.setDesc(TII->get(LatrCFAlu.getOpcode()));
return true;
}
bool R600ClauseMergePass::runOnMachineFunction(MachineFunction &MF) {
if (skipFunction(MF.getFunction()))
return false;
const R600Subtarget &ST = MF.getSubtarget<R600Subtarget>();
TII = ST.getInstrInfo();
for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
BB != BB_E; ++BB) {
MachineBasicBlock &MBB = *BB;
MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
MachineBasicBlock::iterator LatestCFAlu = E;
while (I != E) {
MachineInstr &MI = *I++;
if ((!TII->canBeConsideredALU(MI) && !isCFAlu(MI)) ||
TII->mustBeLastInClause(MI.getOpcode()))
LatestCFAlu = E;
if (!isCFAlu(MI))
continue;
cleanPotentialDisabledCFAlu(MI);
if (LatestCFAlu != E && mergeIfPossible(*LatestCFAlu, MI)) {
MI.eraseFromParent();
} else {
assert(MI.getOperand(8).getImm() && "CF ALU instruction disabled");
LatestCFAlu = MI;
}
}
}
return false;
}
StringRef R600ClauseMergePass::getPassName() const {
return "R600 Merge Clause Markers Pass";
}
llvm::FunctionPass *llvm::createR600ClauseMergePass() {
return new R600ClauseMergePass();
}
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