llvm/llvm/lib/Target/AMDGPU/SIPreEmitPeephole.cpp

//===-- SIPreEmitPeephole.cpp ------------------------------------===//
//
// 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
/// This pass performs the peephole optimizations before code emission.
///
//===----------------------------------------------------------------------===//

#include "AMDGPU.h"
#include "GCNSubtarget.h"
#include "MCTargetDesc/AMDGPUMCTargetDesc.h"
#include "llvm/CodeGen/MachineFunctionPass.h"

usingnamespacellvm;

#define DEBUG_TYPE …

static unsigned SkipThreshold;

static cl::opt<unsigned, true> SkipThresholdFlag(
    "amdgpu-skip-threshold", cl::Hidden,
    cl::desc(
        "Number of instructions before jumping over divergent control flow"),
    cl::location(SkipThreshold), cl::init(12));

namespace {

class SIPreEmitPeephole : public MachineFunctionPass { … };

} // End anonymous namespace.

INITIALIZE_PASS(…)

char SIPreEmitPeephole::ID = …;

char &llvm::SIPreEmitPeepholeID = …;

bool SIPreEmitPeephole::optimizeVccBranch(MachineInstr &MI) const { … }

bool SIPreEmitPeephole::optimizeSetGPR(MachineInstr &First,
                                       MachineInstr &MI) const { … }

bool SIPreEmitPeephole::getBlockDestinations(
    MachineBasicBlock &SrcMBB, MachineBasicBlock *&TrueMBB,
    MachineBasicBlock *&FalseMBB, SmallVectorImpl<MachineOperand> &Cond) { … }

bool SIPreEmitPeephole::mustRetainExeczBranch(
    const MachineBasicBlock &From, const MachineBasicBlock &To) const { … }

// Returns true if the skip branch instruction is removed.
bool SIPreEmitPeephole::removeExeczBranch(MachineInstr &MI,
                                          MachineBasicBlock &SrcMBB) { … }

bool SIPreEmitPeephole::runOnMachineFunction(MachineFunction &MF) { … }