mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-22 02:33:06 +01:00
75 lines
2.6 KiB
C++
75 lines
2.6 KiB
C++
//===- X86MacroFusion.cpp - X86 Macro Fusion ------------------------------===//
|
|
//
|
|
// 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 file contains the X86 implementation of the DAG scheduling
|
|
/// mutation to pair instructions back to back.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "X86MacroFusion.h"
|
|
#include "MCTargetDesc/X86BaseInfo.h"
|
|
#include "X86Subtarget.h"
|
|
#include "llvm/CodeGen/MacroFusion.h"
|
|
#include "llvm/CodeGen/TargetInstrInfo.h"
|
|
|
|
using namespace llvm;
|
|
|
|
static X86::FirstMacroFusionInstKind classifyFirst(const MachineInstr &MI) {
|
|
return X86::classifyFirstOpcodeInMacroFusion(MI.getOpcode());
|
|
}
|
|
|
|
static X86::SecondMacroFusionInstKind classifySecond(const MachineInstr &MI) {
|
|
X86::CondCode CC = X86::getCondFromBranch(MI);
|
|
return X86::classifySecondCondCodeInMacroFusion(CC);
|
|
}
|
|
|
|
/// Check if the instr pair, FirstMI and SecondMI, should be fused
|
|
/// together. Given SecondMI, when FirstMI is unspecified, then check if
|
|
/// SecondMI may be part of a fused pair at all.
|
|
static bool shouldScheduleAdjacent(const TargetInstrInfo &TII,
|
|
const TargetSubtargetInfo &TSI,
|
|
const MachineInstr *FirstMI,
|
|
const MachineInstr &SecondMI) {
|
|
const X86Subtarget &ST = static_cast<const X86Subtarget &>(TSI);
|
|
|
|
// Check if this processor supports any kind of fusion.
|
|
if (!(ST.hasBranchFusion() || ST.hasMacroFusion()))
|
|
return false;
|
|
|
|
const X86::SecondMacroFusionInstKind BranchKind = classifySecond(SecondMI);
|
|
|
|
if (BranchKind == X86::SecondMacroFusionInstKind::Invalid)
|
|
return false; // Second cannot be fused with anything.
|
|
|
|
if (FirstMI == nullptr)
|
|
return true; // We're only checking whether Second can be fused at all.
|
|
|
|
const X86::FirstMacroFusionInstKind TestKind = classifyFirst(*FirstMI);
|
|
|
|
if (ST.hasBranchFusion()) {
|
|
// Branch fusion can merge CMP and TEST with all conditional jumps.
|
|
return (TestKind == X86::FirstMacroFusionInstKind::Cmp ||
|
|
TestKind == X86::FirstMacroFusionInstKind::Test);
|
|
}
|
|
|
|
if (ST.hasMacroFusion()) {
|
|
return X86::isMacroFused(TestKind, BranchKind);
|
|
}
|
|
|
|
llvm_unreachable("unknown fusion type");
|
|
}
|
|
|
|
namespace llvm {
|
|
|
|
std::unique_ptr<ScheduleDAGMutation>
|
|
createX86MacroFusionDAGMutation () {
|
|
return createBranchMacroFusionDAGMutation(shouldScheduleAdjacent);
|
|
}
|
|
|
|
} // end namespace llvm
|