llvm/llvm/lib/Target/PowerPC/PPCVSXFMAMutate.cpp

//===--------------- PPCVSXFMAMutate.cpp - VSX FMA Mutation ---------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This pass mutates the form of VSX FMA instructions to avoid unnecessary
// copies.
//
//===----------------------------------------------------------------------===//

#include "MCTargetDesc/PPCPredicates.h"
#include "PPC.h"
#include "PPCInstrBuilder.h"
#include "PPCInstrInfo.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCTargetMachine.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/CodeGen/SlotIndexes.h"
#include "llvm/InitializePasses.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"

usingnamespacellvm;

// Temporarily disable FMA mutation by default, since it doesn't handle
// cross-basic-block intervals well.
// See: http://lists.llvm.org/pipermail/llvm-dev/2016-February/095669.html
//      http://reviews.llvm.org/D17087
static cl::opt<bool> DisableVSXFMAMutate(
    "disable-ppc-vsx-fma-mutation",
    cl::desc("Disable VSX FMA instruction mutation"), cl::init(true),
    cl::Hidden);

#define DEBUG_TYPE …

namespace llvm { namespace PPC {
  int getAltVSXFMAOpcode(uint16_t Opcode);
} }

namespace {
  // PPCVSXFMAMutate pass - For copies between VSX registers and non-VSX registers
  // (Altivec and scalar floating-point registers), we need to transform the
  // copies into subregister copies with other restrictions.
  struct PPCVSXFMAMutate : public MachineFunctionPass { … };
}

INITIALIZE_PASS_BEGIN(PPCVSXFMAMutate, DEBUG_TYPE,
                      "PowerPC VSX FMA Mutation", false, false)
INITIALIZE_PASS_DEPENDENCY(LiveIntervalsWrapperPass)
INITIALIZE_PASS_DEPENDENCY(SlotIndexesWrapperPass)
INITIALIZE_PASS_DEPENDENCY(MachineDominatorTreeWrapperPass)
INITIALIZE_PASS_END(PPCVSXFMAMutate, DEBUG_TYPE,
                    "PowerPC VSX FMA Mutation", false, false)

char &llvm::PPCVSXFMAMutateID = …;

char PPCVSXFMAMutate::ID = …;
FunctionPass *llvm::createPPCVSXFMAMutatePass() { … }