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llvm-6502/lib/Target/PowerPC/PPCRegisterInfo.cpp
Chris Lattner be6a039ad4 The PPC64 JIT needs register numbers to encode instructions. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29114 91177308-0d34-0410-b5e6-96231b3b80d8
2006-07-11 20:53:55 +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();
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
// 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);
// 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());
MI.getOperand(2).ChangeToRegister(PPC::R0);
} 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();
// Show update of SP.
MachineLocation Dst(MachineLocation::VirtualFP);
MachineLocation Src(MachineLocation::VirtualFP, NegNumbytes);
Moves.push_back(new MachineMove(LabelID, Dst, Src));
BuildMI(MBB, MBBI, PPC::DWARF_LABEL, 1).addImm(LabelID);
}
// 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 is 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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