lib/Target/Sparc/SparcSubtarget.cpp

//===-- SparcSubtarget.cpp - SPARC Subtarget Information ------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the SPARC specific subclass of TargetSubtargetInfo.
//
//===----------------------------------------------------------------------===//

#include "SparcSubtarget.h"
#include "Sparc.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/TargetRegistry.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(const std::string &TT, const std::string &CPU,
                               const std::string &FS,  bool is64Bit) :
  SparcGenSubtargetInfo(TT, CPU, FS),
  IsV9(false),
  V8DeprecatedInsts(false),
  IsVIS(false),
  Is64Bit(is64Bit),
  HasHardQuad(false),
  UsePopc(false) {

  // Determine default and user specified characteristics
  std::string CPUName = CPU;
  if (CPUName.empty())
    CPUName = (is64Bit) ? "v9" : "v8";

  // Parse features string.
  ParseSubtargetFeatures(CPUName, FS);

  // Popc is a v9-only instruction.
  if (!IsV9)
    UsePopc = false;
}


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.
    assert(frameSize % 16 == 0 && "Stack size not 16-byte aligned");
  } 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 = RoundUpToAlignment(frameSize, 8);
  }
  return frameSize;
}