mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-14 11:32:34 +00:00
d0c3817669
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119740 91177308-0d34-0410-b5e6-96231b3b80d8
108 lines
3.7 KiB
C++
108 lines
3.7 KiB
C++
//====- BlackfinFrameInfo.cpp - Blackfin Frame Information ------*- C++ -*-===//
|
|
//
|
|
// 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 Blackfin implementation of TargetFrameInfo class.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "BlackfinFrameInfo.h"
|
|
#include "BlackfinInstrInfo.h"
|
|
#include "llvm/CodeGen/MachineFrameInfo.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
#include "llvm/CodeGen/MachineInstrBuilder.h"
|
|
#include "llvm/Target/TargetOptions.h"
|
|
|
|
using namespace llvm;
|
|
|
|
|
|
// 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 BlackfinFrameInfo::hasFP(const MachineFunction &MF) const {
|
|
const MachineFrameInfo *MFI = MF.getFrameInfo();
|
|
return DisableFramePointerElim(MF) ||
|
|
MFI->adjustsStack() || MFI->hasVarSizedObjects();
|
|
}
|
|
|
|
// Emit a prologue that sets up a stack frame.
|
|
// On function entry, R0-R2 and P0 may hold arguments.
|
|
// R3, P1, and P2 may be used as scratch registers
|
|
void BlackfinFrameInfo::emitPrologue(MachineFunction &MF) const {
|
|
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
|
|
MachineBasicBlock::iterator MBBI = MBB.begin();
|
|
MachineFrameInfo *MFI = MF.getFrameInfo();
|
|
const BlackfinRegisterInfo *RegInfo =
|
|
static_cast<const BlackfinRegisterInfo*>(MF.getTarget().getRegisterInfo());
|
|
const BlackfinInstrInfo &TII =
|
|
*static_cast<const BlackfinInstrInfo*>(MF.getTarget().getInstrInfo());
|
|
|
|
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
|
|
|
|
int FrameSize = MFI->getStackSize();
|
|
if (FrameSize%4) {
|
|
FrameSize = (FrameSize+3) & ~3;
|
|
MFI->setStackSize(FrameSize);
|
|
}
|
|
|
|
if (!hasFP(MF)) {
|
|
assert(!MFI->adjustsStack() &&
|
|
"FP elimination on a non-leaf function is not supported");
|
|
RegInfo->adjustRegister(MBB, MBBI, dl, BF::SP, BF::P1, -FrameSize);
|
|
return;
|
|
}
|
|
|
|
// emit a LINK instruction
|
|
if (FrameSize <= 0x3ffff) {
|
|
BuildMI(MBB, MBBI, dl, TII.get(BF::LINK)).addImm(FrameSize);
|
|
return;
|
|
}
|
|
|
|
// Frame is too big, do a manual LINK:
|
|
// [--SP] = RETS;
|
|
// [--SP] = FP;
|
|
// FP = SP;
|
|
// P1 = -FrameSize;
|
|
// SP = SP + P1;
|
|
BuildMI(MBB, MBBI, dl, TII.get(BF::PUSH))
|
|
.addReg(BF::RETS, RegState::Kill);
|
|
BuildMI(MBB, MBBI, dl, TII.get(BF::PUSH))
|
|
.addReg(BF::FP, RegState::Kill);
|
|
BuildMI(MBB, MBBI, dl, TII.get(BF::MOVE), BF::FP)
|
|
.addReg(BF::SP);
|
|
RegInfo->loadConstant(MBB, MBBI, dl, BF::P1, -FrameSize);
|
|
BuildMI(MBB, MBBI, dl, TII.get(BF::ADDpp), BF::SP)
|
|
.addReg(BF::SP, RegState::Kill)
|
|
.addReg(BF::P1, RegState::Kill);
|
|
|
|
}
|
|
|
|
void BlackfinFrameInfo::emitEpilogue(MachineFunction &MF,
|
|
MachineBasicBlock &MBB) const {
|
|
MachineFrameInfo *MFI = MF.getFrameInfo();
|
|
const BlackfinRegisterInfo *RegInfo =
|
|
static_cast<const BlackfinRegisterInfo*>(MF.getTarget().getRegisterInfo());
|
|
const BlackfinInstrInfo &TII =
|
|
*static_cast<const BlackfinInstrInfo*>(MF.getTarget().getInstrInfo());
|
|
MachineBasicBlock::iterator MBBI = prior(MBB.end());
|
|
DebugLoc dl = MBBI->getDebugLoc();
|
|
|
|
int FrameSize = MFI->getStackSize();
|
|
assert(FrameSize%4 == 0 && "Misaligned frame size");
|
|
|
|
if (!hasFP(MF)) {
|
|
assert(!MFI->adjustsStack() &&
|
|
"FP elimination on a non-leaf function is not supported");
|
|
RegInfo->adjustRegister(MBB, MBBI, dl, BF::SP, BF::P1, FrameSize);
|
|
return;
|
|
}
|
|
|
|
// emit an UNLINK instruction
|
|
BuildMI(MBB, MBBI, dl, TII.get(BF::UNLINK));
|
|
}
|