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llvm-6502/lib/Target/PowerPC/PPCRegisterInfo.cpp
Reid Spencer 3ed469ccd7 For PR786: 
Turn on -Wunused and -Wno-unused-parameter. Clean up most of the resulting
fall out by removing unused variables. Remaining warnings have to do with
unused functions (I didn't want to delete code without review) and unused
variables in generated code. Maintainers should clean up the remaining
issues when they see them. All changes pass DejaGnu tests and Olden.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31380 91177308-0d34-0410-b5e6-96231b3b80d8
2006-11-02 20:25:50 +00:00

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//===- PPCRegisterInfo.cpp - PowerPC Register Information -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the PowerPC implementation of the MRegisterInfo class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "reginfo"
#include "PPC.h"
#include "PPCInstrBuilder.h"
#include "PPCRegisterInfo.h"
#include "PPCSubtarget.h"
#include "llvm/Constants.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineDebugInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/SelectionDAGNodes.h"
#include "llvm/Target/TargetFrameInfo.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/ADT/STLExtras.h"
#include <cstdlib>
#include <iostream>
using namespace llvm;
/// getRegisterNumbering - Given the enum value for some register, e.g.
/// PPC::F14, return the number that it corresponds to (e.g. 14).
unsigned PPCRegisterInfo::getRegisterNumbering(unsigned RegEnum) {
using namespace PPC;
switch (RegEnum) {
case R0 : case X0 : case F0 : case V0 : case CR0: return 0;
case R1 : case X1 : case F1 : case V1 : case CR1: return 1;
case R2 : case X2 : case F2 : case V2 : case CR2: return 2;
case R3 : case X3 : case F3 : case V3 : case CR3: return 3;
case R4 : case X4 : case F4 : case V4 : case CR4: return 4;
case R5 : case X5 : case F5 : case V5 : case CR5: return 5;
case R6 : case X6 : case F6 : case V6 : case CR6: return 6;
case R7 : case X7 : case F7 : case V7 : case CR7: return 7;
case R8 : case X8 : case F8 : case V8 : return 8;
case R9 : case X9 : case F9 : case V9 : return 9;
case R10: case X10: case F10: case V10: return 10;
case R11: case X11: case F11: case V11: return 11;
case R12: case X12: case F12: case V12: return 12;
case R13: case X13: case F13: case V13: return 13;
case R14: case X14: case F14: case V14: return 14;
case R15: case X15: case F15: case V15: return 15;
case R16: case X16: case F16: case V16: return 16;
case R17: case X17: case F17: case V17: return 17;
case R18: case X18: case F18: case V18: return 18;
case R19: case X19: case F19: case V19: return 19;
case R20: case X20: case F20: case V20: return 20;
case R21: case X21: case F21: case V21: return 21;
case R22: case X22: case F22: case V22: return 22;
case R23: case X23: case F23: case V23: return 23;
case R24: case X24: case F24: case V24: return 24;
case R25: case X25: case F25: case V25: return 25;
case R26: case X26: case F26: case V26: return 26;
case R27: case X27: case F27: case V27: return 27;
case R28: case X28: case F28: case V28: return 28;
case R29: case X29: case F29: case V29: return 29;
case R30: case X30: case F30: case V30: return 30;
case R31: case X31: case F31: case V31: return 31;
default:
std::cerr << "Unhandled reg in PPCRegisterInfo::getRegisterNumbering!\n";
abort();
}
}
PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST)
: PPCGenRegisterInfo(PPC::ADJCALLSTACKDOWN, PPC::ADJCALLSTACKUP),
Subtarget(ST) {
ImmToIdxMap[PPC::LD] = PPC::LDX; ImmToIdxMap[PPC::STD] = PPC::STDX;
ImmToIdxMap[PPC::LBZ] = PPC::LBZX; ImmToIdxMap[PPC::STB] = PPC::STBX;
ImmToIdxMap[PPC::LHZ] = PPC::LHZX; ImmToIdxMap[PPC::LHA] = PPC::LHAX;
ImmToIdxMap[PPC::LWZ] = PPC::LWZX; ImmToIdxMap[PPC::LWA] = PPC::LWAX;
ImmToIdxMap[PPC::LFS] = PPC::LFSX; ImmToIdxMap[PPC::LFD] = PPC::LFDX;
ImmToIdxMap[PPC::STH] = PPC::STHX; ImmToIdxMap[PPC::STW] = PPC::STWX;
ImmToIdxMap[PPC::STFS] = PPC::STFSX; ImmToIdxMap[PPC::STFD] = PPC::STFDX;
ImmToIdxMap[PPC::ADDI] = PPC::ADD4;
}
void
PPCRegisterInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, int FrameIdx,
const TargetRegisterClass *RC) const {
if (SrcReg == PPC::LR) {
// FIXME: this spills LR immediately to memory in one step. To do this, we
// use R11, which we know cannot be used in the prolog/epilog. This is a
// hack.
BuildMI(MBB, MI, PPC::MFLR, 1, PPC::R11);
addFrameReference(BuildMI(MBB, MI, PPC::STW, 3).addReg(PPC::R11), FrameIdx);
} else if (RC == PPC::CRRCRegisterClass) {
// FIXME: We use R0 here, because it isn't available for RA.
// We need to store the CR in the low 4-bits of the saved value. First,
// issue a MFCR to save all of the CRBits.
BuildMI(MBB, MI, PPC::MFCR, 0, PPC::R0);
// If the saved register wasn't CR0, shift the bits left so that they are in
// CR0's slot.
if (SrcReg != PPC::CR0) {
unsigned ShiftBits = PPCRegisterInfo::getRegisterNumbering(SrcReg)*4;
// rlwinm r0, r0, ShiftBits, 0, 31.
BuildMI(MBB, MI, PPC::RLWINM, 4, PPC::R0)
.addReg(PPC::R0).addImm(ShiftBits).addImm(0).addImm(31);
}
addFrameReference(BuildMI(MBB, MI, PPC::STW, 3).addReg(PPC::R0), FrameIdx);
} else if (RC == PPC::GPRCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::STW, 3).addReg(SrcReg),FrameIdx);
} else if (RC == PPC::G8RCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::STD, 3).addReg(SrcReg),FrameIdx);
} else if (RC == PPC::F8RCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::STFD, 3).addReg(SrcReg),FrameIdx);
} else if (RC == PPC::F4RCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::STFS, 3).addReg(SrcReg),FrameIdx);
} else if (RC == PPC::VRRCRegisterClass) {
// We don't have indexed addressing for vector loads. Emit:
// R11 = ADDI FI#
// Dest = LVX R0, R11
//
// FIXME: We use R0 here, because it isn't available for RA.
addFrameReference(BuildMI(MBB, MI, PPC::ADDI, 1, PPC::R0), FrameIdx, 0, 0);
BuildMI(MBB, MI, PPC::STVX, 3)
.addReg(SrcReg).addReg(PPC::R0).addReg(PPC::R0);
} else {
assert(0 && "Unknown regclass!");
abort();
}
}
void
PPCRegisterInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC) const {
if (DestReg == PPC::LR) {
addFrameReference(BuildMI(MBB, MI, PPC::LWZ, 2, PPC::R11), FrameIdx);
BuildMI(MBB, MI, PPC::MTLR, 1).addReg(PPC::R11);
} else if (RC == PPC::CRRCRegisterClass) {
// FIXME: We use R0 here, because it isn't available for RA.
addFrameReference(BuildMI(MBB, MI, PPC::LWZ, 2, PPC::R0), FrameIdx);
// If the reloaded register isn't CR0, shift the bits right so that they are
// in the right CR's slot.
if (DestReg != PPC::CR0) {
unsigned ShiftBits = PPCRegisterInfo::getRegisterNumbering(DestReg)*4;
// rlwinm r11, r11, 32-ShiftBits, 0, 31.
BuildMI(MBB, MI, PPC::RLWINM, 4, PPC::R0)
.addReg(PPC::R0).addImm(32-ShiftBits).addImm(0).addImm(31);
}
BuildMI(MBB, MI, PPC::MTCRF, 1, DestReg).addReg(PPC::R0);
} else if (RC == PPC::GPRCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::LWZ, 2, DestReg), FrameIdx);
} else if (RC == PPC::G8RCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::LD, 2, DestReg), FrameIdx);
} else if (RC == PPC::F8RCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::LFD, 2, DestReg), FrameIdx);
} else if (RC == PPC::F4RCRegisterClass) {
addFrameReference(BuildMI(MBB, MI, PPC::LFS, 2, DestReg), FrameIdx);
} else if (RC == PPC::VRRCRegisterClass) {
// We don't have indexed addressing for vector loads. Emit:
// R11 = ADDI FI#
// Dest = LVX R0, R11
//
// FIXME: We use R0 here, because it isn't available for RA.
addFrameReference(BuildMI(MBB, MI, PPC::ADDI, 1, PPC::R0), FrameIdx, 0, 0);
BuildMI(MBB, MI, PPC::LVX, 2, DestReg).addReg(PPC::R0).addReg(PPC::R0);
} else {
assert(0 && "Unknown regclass!");
abort();
}
}
void PPCRegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, unsigned SrcReg,
const TargetRegisterClass *RC) const {
if (RC == PPC::GPRCRegisterClass) {
BuildMI(MBB, MI, PPC::OR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
} else if (RC == PPC::G8RCRegisterClass) {
BuildMI(MBB, MI, PPC::OR8, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
} else if (RC == PPC::F4RCRegisterClass) {
BuildMI(MBB, MI, PPC::FMRS, 1, DestReg).addReg(SrcReg);
} else if (RC == PPC::F8RCRegisterClass) {
BuildMI(MBB, MI, PPC::FMRD, 1, DestReg).addReg(SrcReg);
} else if (RC == PPC::CRRCRegisterClass) {
BuildMI(MBB, MI, PPC::MCRF, 1, DestReg).addReg(SrcReg);
} else if (RC == PPC::VRRCRegisterClass) {
BuildMI(MBB, MI, PPC::VOR, 2, DestReg).addReg(SrcReg).addReg(SrcReg);
} else {
std::cerr << "Attempt to copy register that is not GPR or FPR";
abort();
}
}
const unsigned* PPCRegisterInfo::getCalleeSaveRegs() const {
// 32-bit Darwin calling convention.
static const unsigned Darwin32_CalleeSaveRegs[] = {
PPC::R1 , PPC::R13, PPC::R14, PPC::R15,
PPC::R16, PPC::R17, PPC::R18, PPC::R19,
PPC::R20, PPC::R21, PPC::R22, PPC::R23,
PPC::R24, PPC::R25, PPC::R26, PPC::R27,
PPC::R28, PPC::R29, PPC::R30, PPC::R31,
PPC::F14, PPC::F15, PPC::F16, PPC::F17,
PPC::F18, PPC::F19, PPC::F20, PPC::F21,
PPC::F22, PPC::F23, PPC::F24, PPC::F25,
PPC::F26, PPC::F27, PPC::F28, PPC::F29,
PPC::F30, PPC::F31,
PPC::CR2, PPC::CR3, PPC::CR4,
PPC::V20, PPC::V21, PPC::V22, PPC::V23,
PPC::V24, PPC::V25, PPC::V26, PPC::V27,
PPC::V28, PPC::V29, PPC::V30, PPC::V31,
PPC::LR, 0
};
// 64-bit Darwin calling convention.
static const unsigned Darwin64_CalleeSaveRegs[] = {
PPC::X1 , PPC::X13, PPC::X14, PPC::X15,
PPC::X16, PPC::X17, PPC::X18, PPC::X19,
PPC::X20, PPC::X21, PPC::X22, PPC::X23,
PPC::X24, PPC::X25, PPC::X26, PPC::X27,
PPC::X28, PPC::X29, PPC::X30, PPC::X31,
PPC::F14, PPC::F15, PPC::F16, PPC::F17,
PPC::F18, PPC::F19, PPC::F20, PPC::F21,
PPC::F22, PPC::F23, PPC::F24, PPC::F25,
PPC::F26, PPC::F27, PPC::F28, PPC::F29,
PPC::F30, PPC::F31,
PPC::CR2, PPC::CR3, PPC::CR4,
PPC::V20, PPC::V21, PPC::V22, PPC::V23,
PPC::V24, PPC::V25, PPC::V26, PPC::V27,
PPC::V28, PPC::V29, PPC::V30, PPC::V31,
PPC::LR, 0
};
return Subtarget.isPPC64() ? Darwin64_CalleeSaveRegs :
Darwin32_CalleeSaveRegs;
}
const TargetRegisterClass* const*
PPCRegisterInfo::getCalleeSaveRegClasses() const {
// 32-bit Darwin calling convention.
static const TargetRegisterClass * const Darwin32_CalleeSaveRegClasses[] = {
&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,&PPC::GPRCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::CRRCRegClass,&PPC::CRRCRegClass,&PPC::CRRCRegClass,
&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
&PPC::GPRCRegClass, 0
};
// 64-bit Darwin calling convention.
static const TargetRegisterClass * const Darwin64_CalleeSaveRegClasses[] = {
&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,&PPC::G8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::F8RCRegClass,&PPC::F8RCRegClass,
&PPC::CRRCRegClass,&PPC::CRRCRegClass,&PPC::CRRCRegClass,
&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,&PPC::VRRCRegClass,
&PPC::GPRCRegClass, 0
};
return Subtarget.isPPC64() ? Darwin64_CalleeSaveRegClasses :
Darwin32_CalleeSaveRegClasses;
}
/// foldMemoryOperand - PowerPC (like most RISC's) can only fold spills into
/// copy instructions, turning them into load/store instructions.
MachineInstr *PPCRegisterInfo::foldMemoryOperand(MachineInstr *MI,
unsigned OpNum,
int FrameIndex) const {
// Make sure this is a reg-reg copy. Note that we can't handle MCRF, because
// it takes more than one instruction to store it.
unsigned Opc = MI->getOpcode();
if ((Opc == PPC::OR &&
MI->getOperand(1).getReg() == MI->getOperand(2).getReg())) {
if (OpNum == 0) { // move -> store
unsigned InReg = MI->getOperand(1).getReg();
return addFrameReference(BuildMI(PPC::STW,
3).addReg(InReg), FrameIndex);
} else { // move -> load
unsigned OutReg = MI->getOperand(0).getReg();
return addFrameReference(BuildMI(PPC::LWZ, 2, OutReg), FrameIndex);
}
} else if ((Opc == PPC::OR8 &&
MI->getOperand(1).getReg() == MI->getOperand(2).getReg())) {
if (OpNum == 0) { // move -> store
unsigned InReg = MI->getOperand(1).getReg();
return addFrameReference(BuildMI(PPC::STD,
3).addReg(InReg), FrameIndex);
} else { // move -> load
unsigned OutReg = MI->getOperand(0).getReg();
return addFrameReference(BuildMI(PPC::LD, 2, OutReg), FrameIndex);
}
} else if (Opc == PPC::FMRD) {
if (OpNum == 0) { // move -> store
unsigned InReg = MI->getOperand(1).getReg();
return addFrameReference(BuildMI(PPC::STFD,
3).addReg(InReg), FrameIndex);
} else { // move -> load
unsigned OutReg = MI->getOperand(0).getReg();
return addFrameReference(BuildMI(PPC::LFD, 2, OutReg), FrameIndex);
}
} else if (Opc == PPC::FMRS) {
if (OpNum == 0) { // move -> store
unsigned InReg = MI->getOperand(1).getReg();
return addFrameReference(BuildMI(PPC::STFS,
3).addReg(InReg), FrameIndex);
} else { // move -> load
unsigned OutReg = MI->getOperand(0).getReg();
return addFrameReference(BuildMI(PPC::LFS, 2, OutReg), FrameIndex);
}
}
return 0;
}
//===----------------------------------------------------------------------===//
// Stack Frame Processing methods
//===----------------------------------------------------------------------===//
// 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.
//
static bool hasFP(const MachineFunction &MF) {
const MachineFrameInfo *MFI = MF.getFrameInfo();
// If frame pointers are forced, or if there are variable sized stack objects,
// use a frame pointer.
//
return NoFramePointerElim || MFI->hasVarSizedObjects();
}
void PPCRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
if (hasFP(MF)) {
// If we have a frame pointer, convert as follows:
// ADJCALLSTACKDOWN -> addi, r1, r1, -amount
// ADJCALLSTACKUP -> addi, r1, r1, amount
MachineInstr *Old = I;
unsigned Amount = Old->getOperand(0).getImmedValue();
if (Amount != 0) {
// We need to keep the stack aligned properly. To do this, we round the
// amount of space needed for the outgoing arguments up to the next
// alignment boundary.
unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
Amount = (Amount+Align-1)/Align*Align;
// Replace the pseudo instruction with a new instruction...
if (Old->getOpcode() == PPC::ADJCALLSTACKDOWN) {
BuildMI(MBB, I, PPC::ADDI, 2, PPC::R1).addReg(PPC::R1).addImm(-Amount);
} else {
assert(Old->getOpcode() == PPC::ADJCALLSTACKUP);
BuildMI(MBB, I, PPC::ADDI, 2, PPC::R1).addReg(PPC::R1).addImm(Amount);
}
}
}
MBB.erase(I);
}
void
PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II) const {
unsigned i = 0;
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
while (!MI.getOperand(i).isFrameIndex()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
int FrameIndex = MI.getOperand(i).getFrameIndex();
// Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
MI.getOperand(i).ChangeToRegister(hasFP(MF) ? PPC::R31 : PPC::R1, false);
// Take into account whether it's an add or mem instruction
unsigned OffIdx = (i == 2) ? 1 : 2;
// Figure out if the offset in the instruction is shifted right two bits. This
// is true for instructions like "STD", which the machine implicitly adds two
// low zeros to.
bool isIXAddr = false;
switch (MI.getOpcode()) {
case PPC::LWA:
case PPC::LD:
case PPC::STD:
case PPC::STD_32:
isIXAddr = true;
break;
}
// Now add the frame object offset to the offset from r1.
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex);
if (!isIXAddr)
Offset += MI.getOperand(OffIdx).getImmedValue();
else
Offset += MI.getOperand(OffIdx).getImmedValue() << 2;
// If we're not using a Frame Pointer that has been set to the value of the
// SP before having the stack size subtracted from it, then add the stack size
// to Offset to get the correct offset.
Offset += MF.getFrameInfo()->getStackSize();
if (Offset > 32767 || Offset < -32768) {
// Insert a set of r0 with the full offset value before the ld, st, or add
MachineBasicBlock *MBB = MI.getParent();
BuildMI(*MBB, II, PPC::LIS, 1, PPC::R0).addImm(Offset >> 16);
BuildMI(*MBB, II, PPC::ORI, 2, PPC::R0).addReg(PPC::R0).addImm(Offset);
// convert into indexed form of the instruction
// sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0
// addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
assert(ImmToIdxMap.count(MI.getOpcode()) &&
"No indexed form of load or store available!");
unsigned NewOpcode = ImmToIdxMap.find(MI.getOpcode())->second;
MI.setOpcode(NewOpcode);
MI.getOperand(1).ChangeToRegister(MI.getOperand(i).getReg(), false);
MI.getOperand(2).ChangeToRegister(PPC::R0, false);
} else {
if (isIXAddr) {
assert((Offset & 3) == 0 && "Invalid frame offset!");
Offset >>= 2; // The actual encoded value has the low two bits zero.
}
MI.getOperand(OffIdx).ChangeToImmediate(Offset);
}
}
/// VRRegNo - Map from a numbered VR register to its enum value.
///
static const unsigned short VRRegNo[] = {
PPC::V0 , PPC::V1 , PPC::V2 , PPC::V3 , PPC::V4 , PPC::V5 , PPC::V6 , PPC::V7 ,
PPC::V8 , PPC::V9 , PPC::V10, PPC::V11, PPC::V12, PPC::V13, PPC::V14, PPC::V15,
PPC::V16, PPC::V17, PPC::V18, PPC::V19, PPC::V20, PPC::V21, PPC::V22, PPC::V23,
PPC::V24, PPC::V25, PPC::V26, PPC::V27, PPC::V28, PPC::V29, PPC::V30, PPC::V31
};
/// RemoveVRSaveCode - We have found that this function does not need any code
/// to manipulate the VRSAVE register, even though it uses vector registers.
/// This can happen when the only registers used are known to be live in or out
/// of the function. Remove all of the VRSAVE related code from the function.
static void RemoveVRSaveCode(MachineInstr *MI) {
MachineBasicBlock *Entry = MI->getParent();
MachineFunction *MF = Entry->getParent();
// We know that the MTVRSAVE instruction immediately follows MI. Remove it.
MachineBasicBlock::iterator MBBI = MI;
++MBBI;
assert(MBBI != Entry->end() && MBBI->getOpcode() == PPC::MTVRSAVE);
MBBI->eraseFromParent();
bool RemovedAllMTVRSAVEs = true;
// See if we can find and remove the MTVRSAVE instruction from all of the
// epilog blocks.
const TargetInstrInfo &TII = *MF->getTarget().getInstrInfo();
for (MachineFunction::iterator I = MF->begin(), E = MF->end(); I != E; ++I) {
// If last instruction is a return instruction, add an epilogue
if (!I->empty() && TII.isReturn(I->back().getOpcode())) {
bool FoundIt = false;
for (MBBI = I->end(); MBBI != I->begin(); ) {
--MBBI;
if (MBBI->getOpcode() == PPC::MTVRSAVE) {
MBBI->eraseFromParent(); // remove it.
FoundIt = true;
break;
}
}
RemovedAllMTVRSAVEs &= FoundIt;
}
}
// If we found and removed all MTVRSAVE instructions, remove the read of
// VRSAVE as well.
if (RemovedAllMTVRSAVEs) {
MBBI = MI;
assert(MBBI != Entry->begin() && "UPDATE_VRSAVE is first instr in block?");
--MBBI;
assert(MBBI->getOpcode() == PPC::MFVRSAVE && "VRSAVE instrs wandered?");
MBBI->eraseFromParent();
}
// Finally, nuke the UPDATE_VRSAVE.
MI->eraseFromParent();
}
// HandleVRSaveUpdate - MI is the UPDATE_VRSAVE instruction introduced by the
// instruction selector. Based on the vector registers that have been used,
// transform this into the appropriate ORI instruction.
static void HandleVRSaveUpdate(MachineInstr *MI, const bool *UsedRegs) {
unsigned UsedRegMask = 0;
for (unsigned i = 0; i != 32; ++i)
if (UsedRegs[VRRegNo[i]])
UsedRegMask |= 1 << (31-i);
// Live in and live out values already must be in the mask, so don't bother
// marking them.
MachineFunction *MF = MI->getParent()->getParent();
for (MachineFunction::livein_iterator I =
MF->livein_begin(), E = MF->livein_end(); I != E; ++I) {
unsigned RegNo = PPCRegisterInfo::getRegisterNumbering(I->first);
if (VRRegNo[RegNo] == I->first) // If this really is a vector reg.
UsedRegMask &= ~(1 << (31-RegNo)); // Doesn't need to be marked.
}
for (MachineFunction::liveout_iterator I =
MF->liveout_begin(), E = MF->liveout_end(); I != E; ++I) {
unsigned RegNo = PPCRegisterInfo::getRegisterNumbering(*I);
if (VRRegNo[RegNo] == *I) // If this really is a vector reg.
UsedRegMask &= ~(1 << (31-RegNo)); // Doesn't need to be marked.
}
unsigned SrcReg = MI->getOperand(1).getReg();
unsigned DstReg = MI->getOperand(0).getReg();
// If no registers are used, turn this into a copy.
if (UsedRegMask == 0) {
// Remove all VRSAVE code.
RemoveVRSaveCode(MI);
return;
} else if ((UsedRegMask & 0xFFFF) == UsedRegMask) {
BuildMI(*MI->getParent(), MI, PPC::ORI, 2, DstReg)
.addReg(SrcReg).addImm(UsedRegMask);
} else if ((UsedRegMask & 0xFFFF0000) == UsedRegMask) {
BuildMI(*MI->getParent(), MI, PPC::ORIS, 2, DstReg)
.addReg(SrcReg).addImm(UsedRegMask >> 16);
} else {
BuildMI(*MI->getParent(), MI, PPC::ORIS, 2, DstReg)
.addReg(SrcReg).addImm(UsedRegMask >> 16);
BuildMI(*MI->getParent(), MI, PPC::ORI, 2, DstReg)
.addReg(DstReg).addImm(UsedRegMask & 0xFFFF);
}
// Remove the old UPDATE_VRSAVE instruction.
MI->eraseFromParent();
}
void PPCRegisterInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineDebugInfo *DebugInfo = MFI->getMachineDebugInfo();
// Do we have a frame pointer for this function?
bool HasFP = hasFP(MF);
// Scan the prolog, looking for an UPDATE_VRSAVE instruction. If we find it,
// process it.
for (unsigned i = 0; MBBI != MBB.end(); ++i, ++MBBI) {
if (MBBI->getOpcode() == PPC::UPDATE_VRSAVE) {
HandleVRSaveUpdate(MBBI, MF.getUsedPhysregs());
break;
}
}
// Move MBBI back to the beginning of the function.
MBBI = MBB.begin();
// Get the number of bytes to allocate from the FrameInfo
unsigned NumBytes = MFI->getStackSize();
// Get the alignments provided by the target, and the maximum alignment
// (if any) of the fixed frame objects.
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
unsigned MaxAlign = MFI->getMaxAlignment();
// If we have calls, we cannot use the red zone to store callee save registers
// and we must set up a stack frame, so calculate the necessary size here.
if (MFI->hasCalls()) {
// We reserve argument space for call sites in the function immediately on
// entry to the current function. This eliminates the need for add/sub
// brackets around call sites.
NumBytes += MFI->getMaxCallFrameSize();
}
// If we are a leaf function, and use up to 224 bytes of stack space,
// and don't have a frame pointer, then we do not need to adjust the stack
// pointer (we fit in the Red Zone).
if ((NumBytes == 0) || (NumBytes <= 224 && !HasFP && !MFI->hasCalls() &&
MaxAlign <= TargetAlign)) {
MFI->setStackSize(0);
return;
}
// Add the size of R1 to NumBytes size for the store of R1 to the bottom
// of the stack and round the size to a multiple of the alignment.
unsigned Align = std::max(TargetAlign, MaxAlign);
unsigned GPRSize = 4;
unsigned Size = HasFP ? GPRSize + GPRSize : GPRSize;
NumBytes = (NumBytes+Size+Align-1)/Align*Align;
// Update frame info to pretend that this is part of the stack...
MFI->setStackSize(NumBytes);
int NegNumbytes = -NumBytes;
// Adjust stack pointer: r1 -= numbytes.
// If there is a preferred stack alignment, align R1 now
if (MaxAlign > TargetAlign) {
assert(isPowerOf2_32(MaxAlign) && MaxAlign < 32767 && "Invalid alignment!");
assert(isInt16(0-NumBytes) && "Unhandled stack size and alignment!");
BuildMI(MBB, MBBI, PPC::RLWINM, 4, PPC::R0)
.addReg(PPC::R1).addImm(0).addImm(32-Log2_32(MaxAlign)).addImm(31);
BuildMI(MBB, MBBI, PPC::SUBFIC,2,PPC::R0).addReg(PPC::R0)
.addImm(0-NumBytes);
BuildMI(MBB, MBBI, PPC::STWUX, 3)
.addReg(PPC::R1).addReg(PPC::R1).addReg(PPC::R0);
} else if (NumBytes <= 32768) {
BuildMI(MBB, MBBI, PPC::STWU, 3).addReg(PPC::R1).addImm(NegNumbytes)
.addReg(PPC::R1);
} else {
BuildMI(MBB, MBBI, PPC::LIS, 1, PPC::R0).addImm(NegNumbytes >> 16);
BuildMI(MBB, MBBI, PPC::ORI, 2, PPC::R0).addReg(PPC::R0)
.addImm(NegNumbytes & 0xFFFF);
BuildMI(MBB, MBBI, PPC::STWUX, 3).addReg(PPC::R1).addReg(PPC::R1)
.addReg(PPC::R0);
}
if (DebugInfo && DebugInfo->hasInfo()) {
std::vector<MachineMove *> &Moves = DebugInfo->getFrameMoves();
unsigned LabelID = DebugInfo->NextLabelID();
// Mark effective beginning of when frame pointer becomes valid.
BuildMI(MBB, MBBI, PPC::DWARF_LABEL, 1).addImm(LabelID);
// Show update of SP.
MachineLocation SPDst(MachineLocation::VirtualFP);
MachineLocation SPSrc(MachineLocation::VirtualFP, NegNumbytes);
Moves.push_back(new MachineMove(LabelID, SPDst, SPSrc));
// Add callee saved registers to move list.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
MachineLocation CSDst(MachineLocation::VirtualFP,
MFI->getObjectOffset(CSI[I].getFrameIdx()));
MachineLocation CSSrc(CSI[I].getReg());
Moves.push_back(new MachineMove(LabelID, CSDst, CSSrc));
}
}
// If there is a frame pointer, copy R1 (SP) into R31 (FP)
if (HasFP) {
BuildMI(MBB, MBBI, PPC::STW, 3)
.addReg(PPC::R31).addImm(GPRSize).addReg(PPC::R1);
BuildMI(MBB, MBBI, PPC::OR, 2, PPC::R31).addReg(PPC::R1).addReg(PPC::R1);
}
}
void PPCRegisterInfo::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = prior(MBB.end());
assert(MBBI->getOpcode() == PPC::BLR &&
"Can only insert epilog into returning blocks");
// Get alignment info so we know how to restore r1
const MachineFrameInfo *MFI = MF.getFrameInfo();
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
// Get the number of bytes allocated from the FrameInfo.
unsigned NumBytes = MFI->getStackSize();
unsigned GPRSize = 4;
if (NumBytes != 0) {
// If this function has a frame pointer, load the saved stack pointer from
// its stack slot.
if (hasFP(MF)) {
BuildMI(MBB, MBBI, PPC::LWZ, 2, PPC::R31)
.addImm(GPRSize).addReg(PPC::R31);
}
// The loaded (or persistent) stack pointer value is offseted by the 'stwu'
// on entry to the function. Add this offset back now.
if (NumBytes < 32768 && TargetAlign >= MFI->getMaxAlignment()) {
BuildMI(MBB, MBBI, PPC::ADDI, 2, PPC::R1)
.addReg(PPC::R1).addImm(NumBytes);
} else {
BuildMI(MBB, MBBI, PPC::LWZ, 2, PPC::R1).addImm(0).addReg(PPC::R1);
}
}
}
unsigned PPCRegisterInfo::getRARegister() const {
return PPC::LR;
}
unsigned PPCRegisterInfo::getFrameRegister(MachineFunction &MF) const {
return hasFP(MF) ? PPC::R31 : PPC::R1;
}
void PPCRegisterInfo::getInitialFrameState(std::vector<MachineMove *> &Moves)
const {
// Initial state of the frame pointer is R1.
MachineLocation Dst(MachineLocation::VirtualFP);
MachineLocation Src(PPC::R1, 0);
Moves.push_back(new MachineMove(0, Dst, Src));
}
#include "PPCGenRegisterInfo.inc"
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