mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-28 06:29:45 +00:00
This is to generate correct framesetup code when the function has variable sized allocas. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@182108 91177308-0d34-0410-b5e6-96231b3b80d8
124 lines
4.7 KiB
C++
124 lines
4.7 KiB
C++
//===-- SparcFrameLowering.cpp - Sparc Frame Information ------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file contains the Sparc implementation of TargetFrameLowering class.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "SparcFrameLowering.h"
|
|
#include "SparcInstrInfo.h"
|
|
#include "SparcMachineFunctionInfo.h"
|
|
#include "llvm/CodeGen/MachineFrameInfo.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
#include "llvm/CodeGen/MachineInstrBuilder.h"
|
|
#include "llvm/CodeGen/MachineModuleInfo.h"
|
|
#include "llvm/CodeGen/MachineRegisterInfo.h"
|
|
#include "llvm/IR/DataLayout.h"
|
|
#include "llvm/IR/Function.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include "llvm/Target/TargetOptions.h"
|
|
|
|
using namespace llvm;
|
|
|
|
void SparcFrameLowering::emitPrologue(MachineFunction &MF) const {
|
|
MachineBasicBlock &MBB = MF.front();
|
|
MachineFrameInfo *MFI = MF.getFrameInfo();
|
|
const SparcInstrInfo &TII =
|
|
*static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
|
|
MachineBasicBlock::iterator MBBI = MBB.begin();
|
|
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
|
|
|
|
// Get the number of bytes to allocate from the FrameInfo
|
|
int NumBytes = (int) MFI->getStackSize();
|
|
|
|
if (SubTarget.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.
|
|
NumBytes += 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(NumBytes % 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
|
|
NumBytes += 92;
|
|
|
|
// Round up to next doubleword boundary -- a double-word boundary
|
|
// is required by the ABI.
|
|
NumBytes = RoundUpToAlignment(NumBytes, 8);
|
|
}
|
|
NumBytes = -NumBytes;
|
|
|
|
if (NumBytes >= -4096) {
|
|
BuildMI(MBB, MBBI, dl, TII.get(SP::SAVEri), SP::O6)
|
|
.addReg(SP::O6).addImm(NumBytes);
|
|
} else {
|
|
// Emit this the hard way. This clobbers G1 which we always know is
|
|
// available here.
|
|
unsigned OffHi = (unsigned)NumBytes >> 10U;
|
|
BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1).addImm(OffHi);
|
|
// Emit G1 = G1 + I6
|
|
BuildMI(MBB, MBBI, dl, TII.get(SP::ORri), SP::G1)
|
|
.addReg(SP::G1).addImm(NumBytes & ((1 << 10)-1));
|
|
BuildMI(MBB, MBBI, dl, TII.get(SP::SAVErr), SP::O6)
|
|
.addReg(SP::O6).addReg(SP::G1);
|
|
}
|
|
}
|
|
|
|
void SparcFrameLowering::
|
|
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
|
|
MachineBasicBlock::iterator I) const {
|
|
if (!hasReservedCallFrame(MF)) {
|
|
MachineInstr &MI = *I;
|
|
DebugLoc DL = MI.getDebugLoc();
|
|
int Size = MI.getOperand(0).getImm();
|
|
if (MI.getOpcode() == SP::ADJCALLSTACKDOWN)
|
|
Size = -Size;
|
|
const SparcInstrInfo &TII =
|
|
*static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
|
|
if (Size)
|
|
BuildMI(MBB, I, DL, TII.get(SP::ADDri), SP::O6).addReg(SP::O6)
|
|
.addImm(Size);
|
|
}
|
|
MBB.erase(I);
|
|
}
|
|
|
|
|
|
void SparcFrameLowering::emitEpilogue(MachineFunction &MF,
|
|
MachineBasicBlock &MBB) const {
|
|
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
|
|
const SparcInstrInfo &TII =
|
|
*static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
|
|
DebugLoc dl = MBBI->getDebugLoc();
|
|
assert(MBBI->getOpcode() == SP::RETL &&
|
|
"Can only put epilog before 'retl' instruction!");
|
|
BuildMI(MBB, MBBI, dl, TII.get(SP::RESTORErr), SP::G0).addReg(SP::G0)
|
|
.addReg(SP::G0);
|
|
}
|
|
|
|
bool SparcFrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
|
|
//Reserve call frame if there are no variable sized objects on the stack
|
|
return !MF.getFrameInfo()->hasVarSizedObjects();
|
|
}
|
|
|
|
// hasFP - Return true if the specified function should have a dedicated frame
|
|
// pointer register. This is true if the function has variable sized allocas or
|
|
// if frame pointer elimination is disabled.
|
|
bool SparcFrameLowering::hasFP(const MachineFunction &MF) const {
|
|
const MachineFrameInfo *MFI = MF.getFrameInfo();
|
|
return MF.getTarget().Options.DisableFramePointerElim(MF) ||
|
|
MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken();
|
|
}
|
|
|