SparcSubtarget.cpp

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//===-- SparcSubtarget.cpp - SPARC Subtarget Information ------------------===//
//
// 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 file implements the SPARC specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//
 
#include "SparcSubtarget.h"
#include "SparcSelectionDAGInfo.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/MC/TargetRegistry.h"
#include "llvm/Support/MathExtras.h"
 
using namespace llvm;
 
#define DEBUG_TYPE "sparc-subtarget"
 
#define GET_SUBTARGETINFO_TARGET_DESC
#define GET_SUBTARGETINFO_CTOR
#include "SparcGenSubtargetInfo.inc"
 
void SparcSubtarget::anchor() { }
 
SparcSubtarget &SparcSubtarget::initializeSubtargetDependencies(
    StringRef CPU, StringRef TuneCPU, StringRef FS) {
  const Triple &TT = getTargetTriple();
  // Determine default and user specified characteristics
  std::string CPUName = std::string(CPU);
  if (CPUName.empty())
    CPUName = TT.isSPARC64() ? "v9" : "v8";
 
  if (TuneCPU.empty())
    TuneCPU = CPUName;
 
  // Parse features string.
  ParseSubtargetFeatures(CPUName, TuneCPU, FS);
 
  if (!Is64Bit && TT.isSPARC64()) {
    FeatureBitset Features = getFeatureBits();
    setFeatureBits(Features.set(Sparc::Feature64Bit));
    Is64Bit = true;
  }
 
  // Popc is a v9-only instruction.
  if (!IsV9)
    UsePopc = false;
 
  return *this;
}
 
SparcSubtarget::SparcSubtarget(const StringRef &CPU, const StringRef &TuneCPU,
                               const StringRef &FS, const TargetMachine &TM)
    : SparcGenSubtargetInfo(TM.getTargetTriple(), CPU, TuneCPU, FS),
      ReserveRegister(TM.getMCRegisterInfo()->getNumRegs()),
      InstrInfo(initializeSubtargetDependencies(CPU, TuneCPU, FS)),
      TLInfo(TM, *this), FrameLowering(*this) {
  TSInfo = std::make_unique<SparcSelectionDAGInfo>();
}
 
SparcSubtarget::~SparcSubtarget() = default;
 
const SelectionDAGTargetInfo *SparcSubtarget::getSelectionDAGInfo() const {
  return TSInfo.get();
}
 
int SparcSubtarget::getAdjustedFrameSize(int frameSize) const {
 
  if (is64Bit()) {
    // All 64-bit stack frames must be 16-byte aligned, and must reserve space
    // for spilling the 16 window registers at %sp+BIAS..%sp+BIAS+128.
    frameSize += 128;
    // Frames with calls must also reserve space for 6 outgoing arguments
    // whether they are used or not. LowerCall_64 takes care of that.
    frameSize = alignTo(frameSize, 16);
  } else {
    // Emit the correct save instruction based on the number of bytes in
    // the frame. Minimum stack frame size according to V8 ABI is:
    //   16 words for register window spill
    //    1 word for address of returned aggregate-value
    // +  6 words for passing parameters on the stack
    // ----------
    //   23 words * 4 bytes per word = 92 bytes
    frameSize += 92;
 
    // Round up to next doubleword boundary -- a double-word boundary
    // is required by the ABI.
    frameSize = alignTo(frameSize, 8);
  }
  return frameSize;
}
 
bool SparcSubtarget::enableMachineScheduler() const {
  return true;
}