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llvm-6502/lib/Target/PowerPC/PPCRegisterInfo.cpp
Jim Grosbach fcb4a8ead3 Simplify eliminateFrameIndex() interface back down now that PEI doesn't need 
to try to re-use scavenged frame index reference registers. rdar://8277890

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112241 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-26 23:32:16 +00:00

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//===- PPCRegisterInfo.cpp - PowerPC Register 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 PowerPC implementation of the TargetRegisterInfo
// class.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "reginfo"
#include "PPC.h"
#include "PPCInstrBuilder.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCRegisterInfo.h"
#include "PPCFrameInfo.h"
#include "PPCSubtarget.h"
#include "llvm/CallingConv.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/Type.h"
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.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/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include <cstdlib>
// FIXME This disables some code that aligns the stack to a boundary
// bigger than the default (16 bytes on Darwin) when there is a stack local
// of greater alignment. This does not currently work, because the delta
// between old and new stack pointers is added to offsets that reference
// incoming parameters after the prolog is generated, and the code that
// does that doesn't handle a variable delta. You don't want to do that
// anyway; a better approach is to reserve another register that retains
// to the incoming stack pointer, and reference parameters relative to that.
#define ALIGN_STACK 0
// FIXME (64-bit): Eventually enable by default.
namespace llvm {
cl::opt<bool> EnablePPC32RS("enable-ppc32-regscavenger",
cl::init(false),
cl::desc("Enable PPC32 register scavenger"),
cl::Hidden);
cl::opt<bool> EnablePPC64RS("enable-ppc64-regscavenger",
cl::init(false),
cl::desc("Enable PPC64 register scavenger"),
cl::Hidden);
}
using namespace llvm;
#define EnableRegisterScavenging \
((EnablePPC32RS && !Subtarget.isPPC64()) || \
(EnablePPC64RS && Subtarget.isPPC64()))
// FIXME (64-bit): Should be inlined.
bool
PPCRegisterInfo::requiresRegisterScavenging(const MachineFunction &) const {
return EnableRegisterScavenging;
}
/// 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 0: return 0;
case R0 : case X0 : case F0 : case V0 : case CR0: case CR0LT: return 0;
case R1 : case X1 : case F1 : case V1 : case CR1: case CR0GT: return 1;
case R2 : case X2 : case F2 : case V2 : case CR2: case CR0EQ: return 2;
case R3 : case X3 : case F3 : case V3 : case CR3: case CR0UN: return 3;
case R4 : case X4 : case F4 : case V4 : case CR4: case CR1LT: return 4;
case R5 : case X5 : case F5 : case V5 : case CR5: case CR1GT: return 5;
case R6 : case X6 : case F6 : case V6 : case CR6: case CR1EQ: return 6;
case R7 : case X7 : case F7 : case V7 : case CR7: case CR1UN: return 7;
case R8 : case X8 : case F8 : case V8 : case CR2LT: return 8;
case R9 : case X9 : case F9 : case V9 : case CR2GT: return 9;
case R10: case X10: case F10: case V10: case CR2EQ: return 10;
case R11: case X11: case F11: case V11: case CR2UN: return 11;
case R12: case X12: case F12: case V12: case CR3LT: return 12;
case R13: case X13: case F13: case V13: case CR3GT: return 13;
case R14: case X14: case F14: case V14: case CR3EQ: return 14;
case R15: case X15: case F15: case V15: case CR3UN: return 15;
case R16: case X16: case F16: case V16: case CR4LT: return 16;
case R17: case X17: case F17: case V17: case CR4GT: return 17;
case R18: case X18: case F18: case V18: case CR4EQ: return 18;
case R19: case X19: case F19: case V19: case CR4UN: return 19;
case R20: case X20: case F20: case V20: case CR5LT: return 20;
case R21: case X21: case F21: case V21: case CR5GT: return 21;
case R22: case X22: case F22: case V22: case CR5EQ: return 22;
case R23: case X23: case F23: case V23: case CR5UN: return 23;
case R24: case X24: case F24: case V24: case CR6LT: return 24;
case R25: case X25: case F25: case V25: case CR6GT: return 25;
case R26: case X26: case F26: case V26: case CR6EQ: return 26;
case R27: case X27: case F27: case V27: case CR6UN: return 27;
case R28: case X28: case F28: case V28: case CR7LT: return 28;
case R29: case X29: case F29: case V29: case CR7GT: return 29;
case R30: case X30: case F30: case V30: case CR7EQ: return 30;
case R31: case X31: case F31: case V31: case CR7UN: return 31;
default:
llvm_unreachable("Unhandled reg in PPCRegisterInfo::getRegisterNumbering!");
}
}
PPCRegisterInfo::PPCRegisterInfo(const PPCSubtarget &ST,
const TargetInstrInfo &tii)
: PPCGenRegisterInfo(PPC::ADJCALLSTACKDOWN, PPC::ADJCALLSTACKUP),
Subtarget(ST), TII(tii) {
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;
// 64-bit
ImmToIdxMap[PPC::LHA8] = PPC::LHAX8; ImmToIdxMap[PPC::LBZ8] = PPC::LBZX8;
ImmToIdxMap[PPC::LHZ8] = PPC::LHZX8; ImmToIdxMap[PPC::LWZ8] = PPC::LWZX8;
ImmToIdxMap[PPC::STB8] = PPC::STBX8; ImmToIdxMap[PPC::STH8] = PPC::STHX8;
ImmToIdxMap[PPC::STW8] = PPC::STWX8; ImmToIdxMap[PPC::STDU] = PPC::STDUX;
ImmToIdxMap[PPC::ADDI8] = PPC::ADD8; ImmToIdxMap[PPC::STD_32] = PPC::STDX_32;
}
/// getPointerRegClass - Return the register class to use to hold pointers.
/// This is used for addressing modes.
const TargetRegisterClass *
PPCRegisterInfo::getPointerRegClass(unsigned Kind) const {
if (Subtarget.isPPC64())
return &PPC::G8RCRegClass;
return &PPC::GPRCRegClass;
}
const unsigned*
PPCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
// 32-bit Darwin calling convention.
static const unsigned Darwin32_CalleeSavedRegs[] = {
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::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN,
PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN,
PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN,
PPC::LR, 0
};
// 32-bit SVR4 calling convention.
static const unsigned SVR4_CalleeSavedRegs[] = {
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::VRSAVE,
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::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN,
PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN,
PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN,
0
};
// 64-bit Darwin calling convention.
static const unsigned Darwin64_CalleeSavedRegs[] = {
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::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN,
PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN,
PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN,
PPC::LR8, 0
};
// 64-bit SVR4 calling convention.
static const unsigned SVR4_64_CalleeSavedRegs[] = {
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::VRSAVE,
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::CR2LT, PPC::CR2GT, PPC::CR2EQ, PPC::CR2UN,
PPC::CR3LT, PPC::CR3GT, PPC::CR3EQ, PPC::CR3UN,
PPC::CR4LT, PPC::CR4GT, PPC::CR4EQ, PPC::CR4UN,
0
};
if (Subtarget.isDarwinABI())
return Subtarget.isPPC64() ? Darwin64_CalleeSavedRegs :
Darwin32_CalleeSavedRegs;
return Subtarget.isPPC64() ? SVR4_64_CalleeSavedRegs : SVR4_CalleeSavedRegs;
}
// needsFP - 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 needsFP(const MachineFunction &MF) {
const MachineFrameInfo *MFI = MF.getFrameInfo();
// Naked functions have no stack frame pushed, so we don't have a frame pointer.
if (MF.getFunction()->hasFnAttr(Attribute::Naked))
return false;
return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects() ||
(GuaranteedTailCallOpt && MF.getInfo<PPCFunctionInfo>()->hasFastCall());
}
static bool spillsCR(const MachineFunction &MF) {
const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
return FuncInfo->isCRSpilled();
}
BitVector PPCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
Reserved.set(PPC::R0);
Reserved.set(PPC::R1);
Reserved.set(PPC::LR);
Reserved.set(PPC::LR8);
Reserved.set(PPC::RM);
// The SVR4 ABI reserves r2 and r13
if (Subtarget.isSVR4ABI()) {
Reserved.set(PPC::R2); // System-reserved register
Reserved.set(PPC::R13); // Small Data Area pointer register
}
// Reserve R2 on Darwin to hack around the problem of save/restore of CR
// when the stack frame is too big to address directly; we need two regs.
// This is a hack.
if (Subtarget.isDarwinABI()) {
Reserved.set(PPC::R2);
}
// On PPC64, r13 is the thread pointer. Never allocate this register.
// Note that this is over conservative, as it also prevents allocation of R31
// when the FP is not needed.
if (Subtarget.isPPC64()) {
Reserved.set(PPC::R13);
Reserved.set(PPC::R31);
if (!EnableRegisterScavenging)
Reserved.set(PPC::R0); // FIXME (64-bit): Remove
Reserved.set(PPC::X0);
Reserved.set(PPC::X1);
Reserved.set(PPC::X13);
Reserved.set(PPC::X31);
// The 64-bit SVR4 ABI reserves r2 for the TOC pointer.
if (Subtarget.isSVR4ABI()) {
Reserved.set(PPC::X2);
}
// Reserve R2 on Darwin to hack around the problem of save/restore of CR
// when the stack frame is too big to address directly; we need two regs.
// This is a hack.
if (Subtarget.isDarwinABI()) {
Reserved.set(PPC::X2);
}
}
if (needsFP(MF))
Reserved.set(PPC::R31);
return Reserved;
}
//===----------------------------------------------------------------------===//
// Stack Frame Processing methods
//===----------------------------------------------------------------------===//
// hasFP - Return true if the specified function actually has a dedicated frame
// pointer register. This is true if the function needs a frame pointer and has
// a non-zero stack size.
bool PPCRegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
return MFI->getStackSize() && needsFP(MF);
}
/// MustSaveLR - Return true if this function requires that we save the LR
/// register onto the stack in the prolog and restore it in the epilog of the
/// function.
static bool MustSaveLR(const MachineFunction &MF, unsigned LR) {
const PPCFunctionInfo *MFI = MF.getInfo<PPCFunctionInfo>();
// We need a save/restore of LR if there is any def of LR (which is
// defined by calls, including the PIC setup sequence), or if there is
// some use of the LR stack slot (e.g. for builtin_return_address).
// (LR comes in 32 and 64 bit versions.)
MachineRegisterInfo::def_iterator RI = MF.getRegInfo().def_begin(LR);
return RI !=MF.getRegInfo().def_end() || MFI->isLRStoreRequired();
}
void PPCRegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
if (GuaranteedTailCallOpt && I->getOpcode() == PPC::ADJCALLSTACKUP) {
// Add (actually subtract) back the amount the callee popped on return.
if (int CalleeAmt = I->getOperand(1).getImm()) {
bool is64Bit = Subtarget.isPPC64();
CalleeAmt *= -1;
unsigned StackReg = is64Bit ? PPC::X1 : PPC::R1;
unsigned TmpReg = is64Bit ? PPC::X0 : PPC::R0;
unsigned ADDIInstr = is64Bit ? PPC::ADDI8 : PPC::ADDI;
unsigned ADDInstr = is64Bit ? PPC::ADD8 : PPC::ADD4;
unsigned LISInstr = is64Bit ? PPC::LIS8 : PPC::LIS;
unsigned ORIInstr = is64Bit ? PPC::ORI8 : PPC::ORI;
MachineInstr *MI = I;
DebugLoc dl = MI->getDebugLoc();
if (isInt<16>(CalleeAmt)) {
BuildMI(MBB, I, dl, TII.get(ADDIInstr), StackReg).addReg(StackReg).
addImm(CalleeAmt);
} else {
MachineBasicBlock::iterator MBBI = I;
BuildMI(MBB, MBBI, dl, TII.get(LISInstr), TmpReg)
.addImm(CalleeAmt >> 16);
BuildMI(MBB, MBBI, dl, TII.get(ORIInstr), TmpReg)
.addReg(TmpReg, RegState::Kill)
.addImm(CalleeAmt & 0xFFFF);
BuildMI(MBB, MBBI, dl, TII.get(ADDInstr))
.addReg(StackReg)
.addReg(StackReg)
.addReg(TmpReg);
}
}
}
// Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
MBB.erase(I);
}
/// findScratchRegister - Find a 'free' PPC register. Try for a call-clobbered
/// register first and then a spilled callee-saved register if that fails.
static
unsigned findScratchRegister(MachineBasicBlock::iterator II, RegScavenger *RS,
const TargetRegisterClass *RC, int SPAdj) {
assert(RS && "Register scavenging must be on");
unsigned Reg = RS->FindUnusedReg(RC);
// FIXME: move ARM callee-saved reg scan to target independent code, then
// search for already spilled CS register here.
if (Reg == 0)
Reg = RS->scavengeRegister(RC, II, SPAdj);
return Reg;
}
/// lowerDynamicAlloc - Generate the code for allocating an object in the
/// current frame. The sequence of code with be in the general form
///
/// addi R0, SP, \#frameSize ; get the address of the previous frame
/// stwxu R0, SP, Rnegsize ; add and update the SP with the negated size
/// addi Rnew, SP, \#maxCalFrameSize ; get the top of the allocation
///
void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II,
int SPAdj, RegScavenger *RS) const {
// Get the instruction.
MachineInstr &MI = *II;
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
// Get the basic block's function.
MachineFunction &MF = *MBB.getParent();
// Get the frame info.
MachineFrameInfo *MFI = MF.getFrameInfo();
// Determine whether 64-bit pointers are used.
bool LP64 = Subtarget.isPPC64();
DebugLoc dl = MI.getDebugLoc();
// Get the maximum call stack size.
unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
// Get the total frame size.
unsigned FrameSize = MFI->getStackSize();
// Get stack alignments.
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
unsigned MaxAlign = MFI->getMaxAlignment();
if (MaxAlign > TargetAlign)
report_fatal_error("Dynamic alloca with large aligns not supported");
// Determine the previous frame's address. If FrameSize can't be
// represented as 16 bits or we need special alignment, then we load the
// previous frame's address from 0(SP). Why not do an addis of the hi?
// Because R0 is our only safe tmp register and addi/addis treat R0 as zero.
// Constructing the constant and adding would take 3 instructions.
// Fortunately, a frame greater than 32K is rare.
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
const TargetRegisterClass *RC = LP64 ? G8RC : GPRC;
// FIXME (64-bit): Use "findScratchRegister"
unsigned Reg;
if (EnableRegisterScavenging)
Reg = findScratchRegister(II, RS, RC, SPAdj);
else
Reg = PPC::R0;
if (MaxAlign < TargetAlign && isInt<16>(FrameSize)) {
BuildMI(MBB, II, dl, TII.get(PPC::ADDI), Reg)
.addReg(PPC::R31)
.addImm(FrameSize);
} else if (LP64) {
if (EnableRegisterScavenging) // FIXME (64-bit): Use "true" part.
BuildMI(MBB, II, dl, TII.get(PPC::LD), Reg)
.addImm(0)
.addReg(PPC::X1);
else
BuildMI(MBB, II, dl, TII.get(PPC::LD), PPC::X0)
.addImm(0)
.addReg(PPC::X1);
} else {
BuildMI(MBB, II, dl, TII.get(PPC::LWZ), Reg)
.addImm(0)
.addReg(PPC::R1);
}
// Grow the stack and update the stack pointer link, then determine the
// address of new allocated space.
if (LP64) {
if (EnableRegisterScavenging) // FIXME (64-bit): Use "true" part.
BuildMI(MBB, II, dl, TII.get(PPC::STDUX))
.addReg(Reg, RegState::Kill)
.addReg(PPC::X1)
.addReg(MI.getOperand(1).getReg());
else
BuildMI(MBB, II, dl, TII.get(PPC::STDUX))
.addReg(PPC::X0, RegState::Kill)
.addReg(PPC::X1)
.addReg(MI.getOperand(1).getReg());
if (!MI.getOperand(1).isKill())
BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
.addReg(PPC::X1)
.addImm(maxCallFrameSize);
else
// Implicitly kill the register.
BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
.addReg(PPC::X1)
.addImm(maxCallFrameSize)
.addReg(MI.getOperand(1).getReg(), RegState::ImplicitKill);
} else {
BuildMI(MBB, II, dl, TII.get(PPC::STWUX))
.addReg(Reg, RegState::Kill)
.addReg(PPC::R1)
.addReg(MI.getOperand(1).getReg());
if (!MI.getOperand(1).isKill())
BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg())
.addReg(PPC::R1)
.addImm(maxCallFrameSize);
else
// Implicitly kill the register.
BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg())
.addReg(PPC::R1)
.addImm(maxCallFrameSize)
.addReg(MI.getOperand(1).getReg(), RegState::ImplicitKill);
}
// Discard the DYNALLOC instruction.
MBB.erase(II);
}
/// lowerCRSpilling - Generate the code for spilling a CR register. Instead of
/// reserving a whole register (R0), we scrounge for one here. This generates
/// code like this:
///
/// mfcr rA ; Move the conditional register into GPR rA.
/// rlwinm rA, rA, SB, 0, 31 ; Shift the bits left so they are in CR0's slot.
/// stw rA, FI ; Store rA to the frame.
///
void PPCRegisterInfo::lowerCRSpilling(MachineBasicBlock::iterator II,
unsigned FrameIndex, int SPAdj,
RegScavenger *RS) const {
// Get the instruction.
MachineInstr &MI = *II; // ; SPILL_CR <SrcReg>, <offset>, <FI>
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc dl = MI.getDebugLoc();
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
const TargetRegisterClass *RC = Subtarget.isPPC64() ? G8RC : GPRC;
unsigned Reg = findScratchRegister(II, RS, RC, SPAdj);
unsigned SrcReg = MI.getOperand(0).getReg();
// We need to store the CR in the low 4-bits of the saved value. First, issue
// an MFCRpsued to save all of the CRBits and, if needed, kill the SrcReg.
BuildMI(MBB, II, dl, TII.get(PPC::MFCRpseud), Reg)
.addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
// If the saved register wasn't CR0, shift the bits left so that they are in
// CR0's slot.
if (SrcReg != PPC::CR0)
// rlwinm rA, rA, ShiftBits, 0, 31.
BuildMI(MBB, II, dl, TII.get(PPC::RLWINM), Reg)
.addReg(Reg, RegState::Kill)
.addImm(PPCRegisterInfo::getRegisterNumbering(SrcReg) * 4)
.addImm(0)
.addImm(31);
addFrameReference(BuildMI(MBB, II, dl, TII.get(PPC::STW))
.addReg(Reg, getKillRegState(MI.getOperand(1).getImm())),
FrameIndex);
// Discard the pseudo instruction.
MBB.erase(II);
}
void
PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, RegScavenger *RS) const {
assert(SPAdj == 0 && "Unexpected");
// Get the instruction.
MachineInstr &MI = *II;
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
// Get the basic block's function.
MachineFunction &MF = *MBB.getParent();
// Get the frame info.
MachineFrameInfo *MFI = MF.getFrameInfo();
DebugLoc dl = MI.getDebugLoc();
// Find out which operand is the frame index.
unsigned FIOperandNo = 0;
while (!MI.getOperand(FIOperandNo).isFI()) {
++FIOperandNo;
assert(FIOperandNo != MI.getNumOperands() &&
"Instr doesn't have FrameIndex operand!");
}
// Take into account whether it's an add or mem instruction
unsigned OffsetOperandNo = (FIOperandNo == 2) ? 1 : 2;
if (MI.isInlineAsm())
OffsetOperandNo = FIOperandNo-1;
// Get the frame index.
int FrameIndex = MI.getOperand(FIOperandNo).getIndex();
// Get the frame pointer save index. Users of this index are primarily
// DYNALLOC instructions.
PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
int FPSI = FI->getFramePointerSaveIndex();
// Get the instruction opcode.
unsigned OpC = MI.getOpcode();
// Special case for dynamic alloca.
if (FPSI && FrameIndex == FPSI &&
(OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) {
lowerDynamicAlloc(II, SPAdj, RS);
return;
}
// Special case for pseudo-op SPILL_CR.
if (EnableRegisterScavenging) // FIXME (64-bit): Enable by default.
if (OpC == PPC::SPILL_CR) {
lowerCRSpilling(II, FrameIndex, SPAdj, RS);
return;
}
// Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
MI.getOperand(FIOperandNo).ChangeToRegister(hasFP(MF) ? PPC::R31 : PPC::R1,
false);
// 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 (OpC) {
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 = MFI->getObjectOffset(FrameIndex);
if (!isIXAddr)
Offset += MI.getOperand(OffsetOperandNo).getImm();
else
Offset += MI.getOperand(OffsetOperandNo).getImm() << 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.
// Naked functions have stack size 0, although getStackSize may not reflect that
// because we didn't call all the pieces that compute it for naked functions.
if (!MF.getFunction()->hasFnAttr(Attribute::Naked))
Offset += MFI->getStackSize();
// If we can, encode the offset directly into the instruction. If this is a
// normal PPC "ri" instruction, any 16-bit value can be safely encoded. If
// this is a PPC64 "ix" instruction, only a 16-bit value with the low two bits
// clear can be encoded. This is extremely uncommon, because normally you
// only "std" to a stack slot that is at least 4-byte aligned, but it can
// happen in invalid code.
if (isInt<16>(Offset) && (!isIXAddr || (Offset & 3) == 0)) {
if (isIXAddr)
Offset >>= 2; // The actual encoded value has the low two bits zero.
MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
return;
}
// The offset doesn't fit into a single register, scavenge one to build the
// offset in.
// FIXME: figure out what SPAdj is doing here.
// FIXME (64-bit): Use "findScratchRegister".
unsigned SReg;
if (EnableRegisterScavenging)
SReg = findScratchRegister(II, RS, &PPC::GPRCRegClass, SPAdj);
else
SReg = PPC::R0;
// Insert a set of rA with the full offset value before the ld, st, or add
BuildMI(MBB, II, dl, TII.get(PPC::LIS), SReg)
.addImm(Offset >> 16);
BuildMI(MBB, II, dl, TII.get(PPC::ORI), SReg)
.addReg(SReg, RegState::Kill)
.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
unsigned OperandBase;
if (OpC != TargetOpcode::INLINEASM) {
assert(ImmToIdxMap.count(OpC) &&
"No indexed form of load or store available!");
unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
MI.setDesc(TII.get(NewOpcode));
OperandBase = 1;
} else {
OperandBase = OffsetOperandNo;
}
unsigned StackReg = MI.getOperand(FIOperandNo).getReg();
MI.getOperand(OperandBase).ChangeToRegister(StackReg, false);
MI.getOperand(OperandBase + 1).ChangeToRegister(SReg, false);
}
/// 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.
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() && I->back().getDesc().isReturn()) {
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 TargetInstrInfo &TII) {
MachineFunction *MF = MI->getParent()->getParent();
DebugLoc dl = MI->getDebugLoc();
unsigned UsedRegMask = 0;
for (unsigned i = 0; i != 32; ++i)
if (MF->getRegInfo().isPhysRegUsed(VRRegNo[i]))
UsedRegMask |= 1 << (31-i);
// Live in and live out values already must be in the mask, so don't bother
// marking them.
for (MachineRegisterInfo::livein_iterator
I = MF->getRegInfo().livein_begin(),
E = MF->getRegInfo().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 (MachineRegisterInfo::liveout_iterator
I = MF->getRegInfo().liveout_begin(),
E = MF->getRegInfo().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.
}
// If no registers are used, turn this into a copy.
if (UsedRegMask == 0) {
// Remove all VRSAVE code.
RemoveVRSaveCode(MI);
return;
}
unsigned SrcReg = MI->getOperand(1).getReg();
unsigned DstReg = MI->getOperand(0).getReg();
if ((UsedRegMask & 0xFFFF) == UsedRegMask) {
if (DstReg != SrcReg)
BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
.addReg(SrcReg)
.addImm(UsedRegMask);
else
BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
.addReg(SrcReg, RegState::Kill)
.addImm(UsedRegMask);
} else if ((UsedRegMask & 0xFFFF0000) == UsedRegMask) {
if (DstReg != SrcReg)
BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
.addReg(SrcReg)
.addImm(UsedRegMask >> 16);
else
BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
.addReg(SrcReg, RegState::Kill)
.addImm(UsedRegMask >> 16);
} else {
if (DstReg != SrcReg)
BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
.addReg(SrcReg)
.addImm(UsedRegMask >> 16);
else
BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
.addReg(SrcReg, RegState::Kill)
.addImm(UsedRegMask >> 16);
BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
.addReg(DstReg, RegState::Kill)
.addImm(UsedRegMask & 0xFFFF);
}
// Remove the old UPDATE_VRSAVE instruction.
MI->eraseFromParent();
}
/// determineFrameLayout - Determine the size of the frame and maximum call
/// frame size.
void PPCRegisterInfo::determineFrameLayout(MachineFunction &MF) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
// Get the number of bytes to allocate from the FrameInfo
unsigned FrameSize = MFI->getStackSize();
// Get the alignments provided by the target, and the maximum alignment
// (if any) of the fixed frame objects.
unsigned MaxAlign = MFI->getMaxAlignment();
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
unsigned AlignMask = TargetAlign - 1; //
// If we are a leaf function, and use up to 224 bytes of stack space,
// don't have a frame pointer, calls, or dynamic alloca then we do not need
// to adjust the stack pointer (we fit in the Red Zone).
bool DisableRedZone = MF.getFunction()->hasFnAttr(Attribute::NoRedZone);
// FIXME SVR4 The 32-bit SVR4 ABI has no red zone.
if (!DisableRedZone &&
FrameSize <= 224 && // Fits in red zone.
!MFI->hasVarSizedObjects() && // No dynamic alloca.
!MFI->adjustsStack() && // No calls.
(!ALIGN_STACK || MaxAlign <= TargetAlign)) { // No special alignment.
// No need for frame
MFI->setStackSize(0);
return;
}
// Get the maximum call frame size of all the calls.
unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
// Maximum call frame needs to be at least big enough for linkage and 8 args.
unsigned minCallFrameSize =
PPCFrameInfo::getMinCallFrameSize(Subtarget.isPPC64(),
Subtarget.isDarwinABI());
maxCallFrameSize = std::max(maxCallFrameSize, minCallFrameSize);
// If we have dynamic alloca then maxCallFrameSize needs to be aligned so
// that allocations will be aligned.
if (MFI->hasVarSizedObjects())
maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
// Update maximum call frame size.
MFI->setMaxCallFrameSize(maxCallFrameSize);
// Include call frame size in total.
FrameSize += maxCallFrameSize;
// Make sure the frame is aligned.
FrameSize = (FrameSize + AlignMask) & ~AlignMask;
// Update frame info.
MFI->setStackSize(FrameSize);
}
void
PPCRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS) const {
// Save and clear the LR state.
PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
unsigned LR = getRARegister();
FI->setMustSaveLR(MustSaveLR(MF, LR));
MF.getRegInfo().setPhysRegUnused(LR);
// Save R31 if necessary
int FPSI = FI->getFramePointerSaveIndex();
bool isPPC64 = Subtarget.isPPC64();
bool isDarwinABI = Subtarget.isDarwinABI();
MachineFrameInfo *MFI = MF.getFrameInfo();
// If the frame pointer save index hasn't been defined yet.
if (!FPSI && needsFP(MF)) {
// Find out what the fix offset of the frame pointer save area.
int FPOffset = PPCFrameInfo::getFramePointerSaveOffset(isPPC64,
isDarwinABI);
// Allocate the frame index for frame pointer save area.
FPSI = MF.getFrameInfo()->CreateFixedObject(isPPC64? 8 : 4, FPOffset, true);
// Save the result.
FI->setFramePointerSaveIndex(FPSI);
}
// Reserve stack space to move the linkage area to in case of a tail call.
int TCSPDelta = 0;
if (GuaranteedTailCallOpt && (TCSPDelta = FI->getTailCallSPDelta()) < 0) {
MF.getFrameInfo()->CreateFixedObject(-1 * TCSPDelta, TCSPDelta, true);
}
// Reserve a slot closest to SP or frame pointer if we have a dynalloc or
// a large stack, which will require scavenging a register to materialize a
// large offset.
// FIXME: this doesn't actually check stack size, so is a bit pessimistic
// FIXME: doesn't detect whether or not we need to spill vXX, which requires
// r0 for now.
if (EnableRegisterScavenging) // FIXME (64-bit): Enable.
if (needsFP(MF) || spillsCR(MF)) {
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *RC = isPPC64 ? G8RC : GPRC;
RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
RC->getAlignment(),
false));
}
}
void
PPCRegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF)
const {
// Early exit if not using the SVR4 ABI.
if (!Subtarget.isSVR4ABI()) {
return;
}
// Get callee saved register information.
MachineFrameInfo *FFI = MF.getFrameInfo();
const std::vector<CalleeSavedInfo> &CSI = FFI->getCalleeSavedInfo();
// Early exit if no callee saved registers are modified!
if (CSI.empty() && !needsFP(MF)) {
return;
}
unsigned MinGPR = PPC::R31;
unsigned MinG8R = PPC::X31;
unsigned MinFPR = PPC::F31;
unsigned MinVR = PPC::V31;
bool HasGPSaveArea = false;
bool HasG8SaveArea = false;
bool HasFPSaveArea = false;
bool HasCRSaveArea = false;
bool HasVRSAVESaveArea = false;
bool HasVRSaveArea = false;
SmallVector<CalleeSavedInfo, 18> GPRegs;
SmallVector<CalleeSavedInfo, 18> G8Regs;
SmallVector<CalleeSavedInfo, 18> FPRegs;
SmallVector<CalleeSavedInfo, 18> VRegs;
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
if (PPC::GPRCRegisterClass->contains(Reg)) {
HasGPSaveArea = true;
GPRegs.push_back(CSI[i]);
if (Reg < MinGPR) {
MinGPR = Reg;
}
} else if (PPC::G8RCRegisterClass->contains(Reg)) {
HasG8SaveArea = true;
G8Regs.push_back(CSI[i]);
if (Reg < MinG8R) {
MinG8R = Reg;
}
} else if (PPC::F8RCRegisterClass->contains(Reg)) {
HasFPSaveArea = true;
FPRegs.push_back(CSI[i]);
if (Reg < MinFPR) {
MinFPR = Reg;
}
// FIXME SVR4: Disable CR save area for now.
} else if (PPC::CRBITRCRegisterClass->contains(Reg)
|| PPC::CRRCRegisterClass->contains(Reg)) {
// HasCRSaveArea = true;
} else if (PPC::VRSAVERCRegisterClass->contains(Reg)) {
HasVRSAVESaveArea = true;
} else if (PPC::VRRCRegisterClass->contains(Reg)) {
HasVRSaveArea = true;
VRegs.push_back(CSI[i]);
if (Reg < MinVR) {
MinVR = Reg;
}
} else {
llvm_unreachable("Unknown RegisterClass!");
}
}
PPCFunctionInfo *PFI = MF.getInfo<PPCFunctionInfo>();
int64_t LowerBound = 0;
// Take into account stack space reserved for tail calls.
int TCSPDelta = 0;
if (GuaranteedTailCallOpt && (TCSPDelta = PFI->getTailCallSPDelta()) < 0) {
LowerBound = TCSPDelta;
}
// The Floating-point register save area is right below the back chain word
// of the previous stack frame.
if (HasFPSaveArea) {
for (unsigned i = 0, e = FPRegs.size(); i != e; ++i) {
int FI = FPRegs[i].getFrameIdx();
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
LowerBound -= (31 - getRegisterNumbering(MinFPR) + 1) * 8;
}
// Check whether the frame pointer register is allocated. If so, make sure it
// is spilled to the correct offset.
if (needsFP(MF)) {
HasGPSaveArea = true;
int FI = PFI->getFramePointerSaveIndex();
assert(FI && "No Frame Pointer Save Slot!");
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
// General register save area starts right below the Floating-point
// register save area.
if (HasGPSaveArea || HasG8SaveArea) {
// Move general register save area spill slots down, taking into account
// the size of the Floating-point register save area.
for (unsigned i = 0, e = GPRegs.size(); i != e; ++i) {
int FI = GPRegs[i].getFrameIdx();
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
// Move general register save area spill slots down, taking into account
// the size of the Floating-point register save area.
for (unsigned i = 0, e = G8Regs.size(); i != e; ++i) {
int FI = G8Regs[i].getFrameIdx();
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
unsigned MinReg = std::min<unsigned>(getRegisterNumbering(MinGPR),
getRegisterNumbering(MinG8R));
if (Subtarget.isPPC64()) {
LowerBound -= (31 - MinReg + 1) * 8;
} else {
LowerBound -= (31 - MinReg + 1) * 4;
}
}
// The CR save area is below the general register save area.
if (HasCRSaveArea) {
// FIXME SVR4: Is it actually possible to have multiple elements in CSI
// which have the CR/CRBIT register class?
// Adjust the frame index of the CR spill slot.
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
if (PPC::CRBITRCRegisterClass->contains(Reg) ||
PPC::CRRCRegisterClass->contains(Reg)) {
int FI = CSI[i].getFrameIdx();
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
}
LowerBound -= 4; // The CR save area is always 4 bytes long.
}
if (HasVRSAVESaveArea) {
// FIXME SVR4: Is it actually possible to have multiple elements in CSI
// which have the VRSAVE register class?
// Adjust the frame index of the VRSAVE spill slot.
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
if (PPC::VRSAVERCRegisterClass->contains(Reg)) {
int FI = CSI[i].getFrameIdx();
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
}
LowerBound -= 4; // The VRSAVE save area is always 4 bytes long.
}
if (HasVRSaveArea) {
// Insert alignment padding, we need 16-byte alignment.
LowerBound = (LowerBound - 15) & ~(15);
for (unsigned i = 0, e = VRegs.size(); i != e; ++i) {
int FI = VRegs[i].getFrameIdx();
FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
}
}
}
void
PPCRegisterInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo &MMI = MF.getMMI();
DebugLoc dl;
bool needsFrameMoves = MMI.hasDebugInfo() ||
!MF.getFunction()->doesNotThrow() ||
UnwindTablesMandatory;
// Prepare for frame info.
MCSymbol *FrameLabel = 0;
// 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, TII);
break;
}
}
// Move MBBI back to the beginning of the function.
MBBI = MBB.begin();
// Work out frame sizes.
determineFrameLayout(MF);
unsigned FrameSize = MFI->getStackSize();
int NegFrameSize = -FrameSize;
// Get processor type.
bool isPPC64 = Subtarget.isPPC64();
// Get operating system
bool isDarwinABI = Subtarget.isDarwinABI();
// Check if the link register (LR) must be saved.
PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
bool MustSaveLR = FI->mustSaveLR();
// Do we have a frame pointer for this function?
bool HasFP = hasFP(MF) && FrameSize;
int LROffset = PPCFrameInfo::getReturnSaveOffset(isPPC64, isDarwinABI);
int FPOffset = 0;
if (HasFP) {
if (Subtarget.isSVR4ABI()) {
MachineFrameInfo *FFI = MF.getFrameInfo();
int FPIndex = FI->getFramePointerSaveIndex();
assert(FPIndex && "No Frame Pointer Save Slot!");
FPOffset = FFI->getObjectOffset(FPIndex);
} else {
FPOffset = PPCFrameInfo::getFramePointerSaveOffset(isPPC64, isDarwinABI);
}
}
if (isPPC64) {
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::MFLR8), PPC::X0);
if (HasFP)
BuildMI(MBB, MBBI, dl, TII.get(PPC::STD))
.addReg(PPC::X31)
.addImm(FPOffset/4)
.addReg(PPC::X1);
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::STD))
.addReg(PPC::X0)
.addImm(LROffset / 4)
.addReg(PPC::X1);
} else {
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::MFLR), PPC::R0);
if (HasFP)
BuildMI(MBB, MBBI, dl, TII.get(PPC::STW))
.addReg(PPC::R31)
.addImm(FPOffset)
.addReg(PPC::R1);
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::STW))
.addReg(PPC::R0)
.addImm(LROffset)
.addReg(PPC::R1);
}
// Skip if a leaf routine.
if (!FrameSize) return;
// Get stack alignments.
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
unsigned MaxAlign = MFI->getMaxAlignment();
// Adjust stack pointer: r1 += NegFrameSize.
// If there is a preferred stack alignment, align R1 now
if (!isPPC64) {
// PPC32.
if (ALIGN_STACK && MaxAlign > TargetAlign) {
assert(isPowerOf2_32(MaxAlign) && isInt<16>(MaxAlign) &&
"Invalid alignment!");
assert(isInt<16>(NegFrameSize) && "Unhandled stack size and alignment!");
BuildMI(MBB, MBBI, dl, TII.get(PPC::RLWINM), PPC::R0)
.addReg(PPC::R1)
.addImm(0)
.addImm(32 - Log2_32(MaxAlign))
.addImm(31);
BuildMI(MBB, MBBI, dl, TII.get(PPC::SUBFIC) ,PPC::R0)
.addReg(PPC::R0, RegState::Kill)
.addImm(NegFrameSize);
BuildMI(MBB, MBBI, dl, TII.get(PPC::STWUX))
.addReg(PPC::R1)
.addReg(PPC::R1)
.addReg(PPC::R0);
} else if (isInt<16>(NegFrameSize)) {
BuildMI(MBB, MBBI, dl, TII.get(PPC::STWU), PPC::R1)
.addReg(PPC::R1)
.addImm(NegFrameSize)
.addReg(PPC::R1);
} else {
BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS), PPC::R0)
.addImm(NegFrameSize >> 16);
BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI), PPC::R0)
.addReg(PPC::R0, RegState::Kill)
.addImm(NegFrameSize & 0xFFFF);
BuildMI(MBB, MBBI, dl, TII.get(PPC::STWUX))
.addReg(PPC::R1)
.addReg(PPC::R1)
.addReg(PPC::R0);
}
} else { // PPC64.
if (ALIGN_STACK && MaxAlign > TargetAlign) {
assert(isPowerOf2_32(MaxAlign) && isInt<16>(MaxAlign) &&
"Invalid alignment!");
assert(isInt<16>(NegFrameSize) && "Unhandled stack size and alignment!");
BuildMI(MBB, MBBI, dl, TII.get(PPC::RLDICL), PPC::X0)
.addReg(PPC::X1)
.addImm(0)
.addImm(64 - Log2_32(MaxAlign));
BuildMI(MBB, MBBI, dl, TII.get(PPC::SUBFIC8), PPC::X0)
.addReg(PPC::X0)
.addImm(NegFrameSize);
BuildMI(MBB, MBBI, dl, TII.get(PPC::STDUX))
.addReg(PPC::X1)
.addReg(PPC::X1)
.addReg(PPC::X0);
} else if (isInt<16>(NegFrameSize)) {
BuildMI(MBB, MBBI, dl, TII.get(PPC::STDU), PPC::X1)
.addReg(PPC::X1)
.addImm(NegFrameSize / 4)
.addReg(PPC::X1);
} else {
BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS8), PPC::X0)
.addImm(NegFrameSize >> 16);
BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI8), PPC::X0)
.addReg(PPC::X0, RegState::Kill)
.addImm(NegFrameSize & 0xFFFF);
BuildMI(MBB, MBBI, dl, TII.get(PPC::STDUX))
.addReg(PPC::X1)
.addReg(PPC::X1)
.addReg(PPC::X0);
}
}
std::vector<MachineMove> &Moves = MMI.getFrameMoves();
// Add the "machine moves" for the instructions we generated above, but in
// reverse order.
if (needsFrameMoves) {
// Mark effective beginning of when frame pointer becomes valid.
FrameLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl, TII.get(PPC::PROLOG_LABEL)).addSym(FrameLabel);
// Show update of SP.
if (NegFrameSize) {
MachineLocation SPDst(MachineLocation::VirtualFP);
MachineLocation SPSrc(MachineLocation::VirtualFP, NegFrameSize);
Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
} else {
MachineLocation SP(isPPC64 ? PPC::X31 : PPC::R31);
Moves.push_back(MachineMove(FrameLabel, SP, SP));
}
if (HasFP) {
MachineLocation FPDst(MachineLocation::VirtualFP, FPOffset);
MachineLocation FPSrc(isPPC64 ? PPC::X31 : PPC::R31);
Moves.push_back(MachineMove(FrameLabel, FPDst, FPSrc));
}
if (MustSaveLR) {
MachineLocation LRDst(MachineLocation::VirtualFP, LROffset);
MachineLocation LRSrc(isPPC64 ? PPC::LR8 : PPC::LR);
Moves.push_back(MachineMove(FrameLabel, LRDst, LRSrc));
}
}
MCSymbol *ReadyLabel = 0;
// If there is a frame pointer, copy R1 into R31
if (HasFP) {
if (!isPPC64) {
BuildMI(MBB, MBBI, dl, TII.get(PPC::OR), PPC::R31)
.addReg(PPC::R1)
.addReg(PPC::R1);
} else {
BuildMI(MBB, MBBI, dl, TII.get(PPC::OR8), PPC::X31)
.addReg(PPC::X1)
.addReg(PPC::X1);
}
if (needsFrameMoves) {
ReadyLabel = MMI.getContext().CreateTempSymbol();
// Mark effective beginning of when frame pointer is ready.
BuildMI(MBB, MBBI, dl, TII.get(PPC::PROLOG_LABEL)).addSym(ReadyLabel);
MachineLocation FPDst(HasFP ? (isPPC64 ? PPC::X31 : PPC::R31) :
(isPPC64 ? PPC::X1 : PPC::R1));
MachineLocation FPSrc(MachineLocation::VirtualFP);
Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc));
}
}
if (needsFrameMoves) {
MCSymbol *Label = HasFP ? ReadyLabel : FrameLabel;
// Add callee saved registers to move list.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
unsigned Reg = CSI[I].getReg();
if (Reg == PPC::LR || Reg == PPC::LR8 || Reg == PPC::RM) continue;
MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
MachineLocation CSSrc(Reg);
Moves.push_back(MachineMove(Label, CSDst, CSSrc));
}
}
}
void PPCRegisterInfo::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = prior(MBB.end());
unsigned RetOpcode = MBBI->getOpcode();
DebugLoc dl;
assert( (RetOpcode == PPC::BLR ||
RetOpcode == PPC::TCRETURNri ||
RetOpcode == PPC::TCRETURNdi ||
RetOpcode == PPC::TCRETURNai ||
RetOpcode == PPC::TCRETURNri8 ||
RetOpcode == PPC::TCRETURNdi8 ||
RetOpcode == PPC::TCRETURNai8) &&
"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();
unsigned MaxAlign = MFI->getMaxAlignment();
// Get the number of bytes allocated from the FrameInfo.
int FrameSize = MFI->getStackSize();
// Get processor type.
bool isPPC64 = Subtarget.isPPC64();
// Get operating system
bool isDarwinABI = Subtarget.isDarwinABI();
// Check if the link register (LR) has been saved.
PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
bool MustSaveLR = FI->mustSaveLR();
// Do we have a frame pointer for this function?
bool HasFP = hasFP(MF) && FrameSize;
int LROffset = PPCFrameInfo::getReturnSaveOffset(isPPC64, isDarwinABI);
int FPOffset = 0;
if (HasFP) {
if (Subtarget.isSVR4ABI()) {
MachineFrameInfo *FFI = MF.getFrameInfo();
int FPIndex = FI->getFramePointerSaveIndex();
assert(FPIndex && "No Frame Pointer Save Slot!");
FPOffset = FFI->getObjectOffset(FPIndex);
} else {
FPOffset = PPCFrameInfo::getFramePointerSaveOffset(isPPC64, isDarwinABI);
}
}
bool UsesTCRet = RetOpcode == PPC::TCRETURNri ||
RetOpcode == PPC::TCRETURNdi ||
RetOpcode == PPC::TCRETURNai ||
RetOpcode == PPC::TCRETURNri8 ||
RetOpcode == PPC::TCRETURNdi8 ||
RetOpcode == PPC::TCRETURNai8;
if (UsesTCRet) {
int MaxTCRetDelta = FI->getTailCallSPDelta();
MachineOperand &StackAdjust = MBBI->getOperand(1);
assert(StackAdjust.isImm() && "Expecting immediate value.");
// Adjust stack pointer.
int StackAdj = StackAdjust.getImm();
int Delta = StackAdj - MaxTCRetDelta;
assert((Delta >= 0) && "Delta must be positive");
if (MaxTCRetDelta>0)
FrameSize += (StackAdj +Delta);
else
FrameSize += StackAdj;
}
if (FrameSize) {
// The loaded (or persistent) stack pointer value is offset by the 'stwu'
// on entry to the function. Add this offset back now.
if (!isPPC64) {
// If this function contained a fastcc call and GuaranteedTailCallOpt is
// enabled (=> hasFastCall()==true) the fastcc call might contain a tail
// call which invalidates the stack pointer value in SP(0). So we use the
// value of R31 in this case.
if (FI->hasFastCall() && isInt<16>(FrameSize)) {
assert(hasFP(MF) && "Expecting a valid the frame pointer.");
BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI), PPC::R1)
.addReg(PPC::R31).addImm(FrameSize);
} else if(FI->hasFastCall()) {
BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS), PPC::R0)
.addImm(FrameSize >> 16);
BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI), PPC::R0)
.addReg(PPC::R0, RegState::Kill)
.addImm(FrameSize & 0xFFFF);
BuildMI(MBB, MBBI, dl, TII.get(PPC::ADD4))
.addReg(PPC::R1)
.addReg(PPC::R31)
.addReg(PPC::R0);
} else if (isInt<16>(FrameSize) &&
(!ALIGN_STACK || TargetAlign >= MaxAlign) &&
!MFI->hasVarSizedObjects()) {
BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI), PPC::R1)
.addReg(PPC::R1).addImm(FrameSize);
} else {
BuildMI(MBB, MBBI, dl, TII.get(PPC::LWZ),PPC::R1)
.addImm(0).addReg(PPC::R1);
}
} else {
if (FI->hasFastCall() && isInt<16>(FrameSize)) {
assert(hasFP(MF) && "Expecting a valid the frame pointer.");
BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI8), PPC::X1)
.addReg(PPC::X31).addImm(FrameSize);
} else if(FI->hasFastCall()) {
BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS8), PPC::X0)
.addImm(FrameSize >> 16);
BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI8), PPC::X0)
.addReg(PPC::X0, RegState::Kill)
.addImm(FrameSize & 0xFFFF);
BuildMI(MBB, MBBI, dl, TII.get(PPC::ADD8))
.addReg(PPC::X1)
.addReg(PPC::X31)
.addReg(PPC::X0);
} else if (isInt<16>(FrameSize) && TargetAlign >= MaxAlign &&
!MFI->hasVarSizedObjects()) {
BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI8), PPC::X1)
.addReg(PPC::X1).addImm(FrameSize);
} else {
BuildMI(MBB, MBBI, dl, TII.get(PPC::LD), PPC::X1)
.addImm(0).addReg(PPC::X1);
}
}
}
if (isPPC64) {
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::LD), PPC::X0)
.addImm(LROffset/4).addReg(PPC::X1);
if (HasFP)
BuildMI(MBB, MBBI, dl, TII.get(PPC::LD), PPC::X31)
.addImm(FPOffset/4).addReg(PPC::X1);
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::MTLR8)).addReg(PPC::X0);
} else {
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::LWZ), PPC::R0)
.addImm(LROffset).addReg(PPC::R1);
if (HasFP)
BuildMI(MBB, MBBI, dl, TII.get(PPC::LWZ), PPC::R31)
.addImm(FPOffset).addReg(PPC::R1);
if (MustSaveLR)
BuildMI(MBB, MBBI, dl, TII.get(PPC::MTLR)).addReg(PPC::R0);
}
// Callee pop calling convention. Pop parameter/linkage area. Used for tail
// call optimization
if (GuaranteedTailCallOpt && RetOpcode == PPC::BLR &&
MF.getFunction()->getCallingConv() == CallingConv::Fast) {
PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
unsigned CallerAllocatedAmt = FI->getMinReservedArea();
unsigned StackReg = isPPC64 ? PPC::X1 : PPC::R1;
unsigned FPReg = isPPC64 ? PPC::X31 : PPC::R31;
unsigned TmpReg = isPPC64 ? PPC::X0 : PPC::R0;
unsigned ADDIInstr = isPPC64 ? PPC::ADDI8 : PPC::ADDI;
unsigned ADDInstr = isPPC64 ? PPC::ADD8 : PPC::ADD4;
unsigned LISInstr = isPPC64 ? PPC::LIS8 : PPC::LIS;
unsigned ORIInstr = isPPC64 ? PPC::ORI8 : PPC::ORI;
if (CallerAllocatedAmt && isInt<16>(CallerAllocatedAmt)) {
BuildMI(MBB, MBBI, dl, TII.get(ADDIInstr), StackReg)
.addReg(StackReg).addImm(CallerAllocatedAmt);
} else {
BuildMI(MBB, MBBI, dl, TII.get(LISInstr), TmpReg)
.addImm(CallerAllocatedAmt >> 16);
BuildMI(MBB, MBBI, dl, TII.get(ORIInstr), TmpReg)
.addReg(TmpReg, RegState::Kill)
.addImm(CallerAllocatedAmt & 0xFFFF);
BuildMI(MBB, MBBI, dl, TII.get(ADDInstr))
.addReg(StackReg)
.addReg(FPReg)
.addReg(TmpReg);
}
} else if (RetOpcode == PPC::TCRETURNdi) {
MBBI = prior(MBB.end());
MachineOperand &JumpTarget = MBBI->getOperand(0);
BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB)).
addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset());
} else if (RetOpcode == PPC::TCRETURNri) {
MBBI = prior(MBB.end());
assert(MBBI->getOperand(0).isReg() && "Expecting register operand.");
BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR));
} else if (RetOpcode == PPC::TCRETURNai) {
MBBI = prior(MBB.end());
MachineOperand &JumpTarget = MBBI->getOperand(0);
BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA)).addImm(JumpTarget.getImm());
} else if (RetOpcode == PPC::TCRETURNdi8) {
MBBI = prior(MBB.end());
MachineOperand &JumpTarget = MBBI->getOperand(0);
BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB8)).
addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset());
} else if (RetOpcode == PPC::TCRETURNri8) {
MBBI = prior(MBB.end());
assert(MBBI->getOperand(0).isReg() && "Expecting register operand.");
BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR8));
} else if (RetOpcode == PPC::TCRETURNai8) {
MBBI = prior(MBB.end());
MachineOperand &JumpTarget = MBBI->getOperand(0);
BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA8)).addImm(JumpTarget.getImm());
}
}
unsigned PPCRegisterInfo::getRARegister() const {
return !Subtarget.isPPC64() ? PPC::LR : PPC::LR8;
}
unsigned PPCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
if (!Subtarget.isPPC64())
return hasFP(MF) ? PPC::R31 : PPC::R1;
else
return hasFP(MF) ? PPC::X31 : PPC::X1;
}
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(MachineMove(0, Dst, Src));
}
unsigned PPCRegisterInfo::getEHExceptionRegister() const {
return !Subtarget.isPPC64() ? PPC::R3 : PPC::X3;
}
unsigned PPCRegisterInfo::getEHHandlerRegister() const {
return !Subtarget.isPPC64() ? PPC::R4 : PPC::X4;
}
int PPCRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
// FIXME: Most probably dwarf numbers differs for Linux and Darwin
return PPCGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
}
#include "PPCGenRegisterInfo.inc"
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