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swiftshader / SwiftShader / 655fd07eaafc25f432be07c5010d94410965c6ec / . / third_party / llvm-10.0 / llvm / lib / Target / PowerPC / PPCRegisterInfo.cpp
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//===-- PPCRegisterInfo.cpp - PowerPC Register Information ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the PowerPC implementation of the TargetRegisterInfo
// class.
//
//===----------------------------------------------------------------------===//
#include "PPCRegisterInfo.h"
#include "PPCFrameLowering.h"
#include "PPCInstrBuilder.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCSubtarget.h"
#include "PPCTargetMachine.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/CodeGen/TargetFrameLowering.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/Type.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/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include <cstdlib>
using namespace llvm;
#define DEBUG_TYPE "reginfo"
#define GET_REGINFO_TARGET_DESC
#include "PPCGenRegisterInfo.inc"
STATISTIC(InflateGPRC, "Number of gprc inputs for getLargestLegalClass");
STATISTIC(InflateGP8RC, "Number of g8rc inputs for getLargestLegalClass");
static cl::opt<bool>
EnableBasePointer("ppc-use-base-pointer", cl::Hidden, cl::init(true),
cl::desc("Enable use of a base pointer for complex stack frames"));
static cl::opt<bool>
AlwaysBasePointer("ppc-always-use-base-pointer", cl::Hidden, cl::init(false),
cl::desc("Force the use of a base pointer in every function"));
static cl::opt<bool>
EnableGPRToVecSpills("ppc-enable-gpr-to-vsr-spills", cl::Hidden, cl::init(false),
cl::desc("Enable spills from gpr to vsr rather than stack"));
static cl::opt<bool>
StackPtrConst("ppc-stack-ptr-caller-preserved",
cl::desc("Consider R1 caller preserved so stack saves of "
"caller preserved registers can be LICM candidates"),
cl::init(true), cl::Hidden);
static cl::opt<unsigned>
MaxCRBitSpillDist("ppc-max-crbit-spill-dist",
cl::desc("Maximum search distance for definition of CR bit "
"spill on ppc"),
cl::Hidden, cl::init(100));
static unsigned offsetMinAlignForOpcode(unsigned OpC);
PPCRegisterInfo::PPCRegisterInfo(const PPCTargetMachine &TM)
: PPCGenRegisterInfo(TM.isPPC64() ? PPC::LR8 : PPC::LR,
TM.isPPC64() ? 0 : 1,
TM.isPPC64() ? 0 : 1),
TM(TM) {
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;
ImmToIdxMap[PPC::LWA_32] = PPC::LWAX_32;
// 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;
// VSX
ImmToIdxMap[PPC::DFLOADf32] = PPC::LXSSPX;
ImmToIdxMap[PPC::DFLOADf64] = PPC::LXSDX;
ImmToIdxMap[PPC::SPILLTOVSR_LD] = PPC::SPILLTOVSR_LDX;
ImmToIdxMap[PPC::SPILLTOVSR_ST] = PPC::SPILLTOVSR_STX;
ImmToIdxMap[PPC::DFSTOREf32] = PPC::STXSSPX;
ImmToIdxMap[PPC::DFSTOREf64] = PPC::STXSDX;
ImmToIdxMap[PPC::LXV] = PPC::LXVX;
ImmToIdxMap[PPC::LXSD] = PPC::LXSDX;
ImmToIdxMap[PPC::LXSSP] = PPC::LXSSPX;
ImmToIdxMap[PPC::STXV] = PPC::STXVX;
ImmToIdxMap[PPC::STXSD] = PPC::STXSDX;
ImmToIdxMap[PPC::STXSSP] = PPC::STXSSPX;
// SPE
ImmToIdxMap[PPC::EVLDD] = PPC::EVLDDX;
ImmToIdxMap[PPC::EVSTDD] = PPC::EVSTDDX;
ImmToIdxMap[PPC::SPESTW] = PPC::SPESTWX;
ImmToIdxMap[PPC::SPELWZ] = PPC::SPELWZX;
}
/// getPointerRegClass - Return the register class to use to hold pointers.
/// This is used for addressing modes.
const TargetRegisterClass *
PPCRegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind)
const {
// Note that PPCInstrInfo::FoldImmediate also directly uses this Kind value
// when it checks for ZERO folding.
if (Kind == 1) {
if (TM.isPPC64())
return &PPC::G8RC_NOX0RegClass;
return &PPC::GPRC_NOR0RegClass;
}
if (TM.isPPC64())
return &PPC::G8RCRegClass;
return &PPC::GPRCRegClass;
}
const MCPhysReg*
PPCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
const PPCSubtarget &Subtarget = MF->getSubtarget<PPCSubtarget>();
if (MF->getFunction().getCallingConv() == CallingConv::AnyReg) {
if (Subtarget.hasVSX())
return CSR_64_AllRegs_VSX_SaveList;
if (Subtarget.hasAltivec())
return CSR_64_AllRegs_Altivec_SaveList;
return CSR_64_AllRegs_SaveList;
}
if (Subtarget.isDarwinABI())
return TM.isPPC64()
? (Subtarget.hasAltivec() ? CSR_Darwin64_Altivec_SaveList
: CSR_Darwin64_SaveList)
: (Subtarget.hasAltivec() ? CSR_Darwin32_Altivec_SaveList
: CSR_Darwin32_SaveList);
if (TM.isPPC64() && MF->getInfo<PPCFunctionInfo>()->isSplitCSR())
return CSR_SRV464_TLS_PE_SaveList;
// On PPC64, we might need to save r2 (but only if it is not reserved).
bool SaveR2 = MF->getRegInfo().isAllocatable(PPC::X2);
// Cold calling convention CSRs.
if (MF->getFunction().getCallingConv() == CallingConv::Cold) {
if (TM.isPPC64()) {
if (Subtarget.hasAltivec())
return SaveR2 ? CSR_SVR64_ColdCC_R2_Altivec_SaveList
: CSR_SVR64_ColdCC_Altivec_SaveList;
return SaveR2 ? CSR_SVR64_ColdCC_R2_SaveList
: CSR_SVR64_ColdCC_SaveList;
}
// 32-bit targets.
if (Subtarget.hasAltivec())
return CSR_SVR32_ColdCC_Altivec_SaveList;
else if (Subtarget.hasSPE())
return CSR_SVR32_ColdCC_SPE_SaveList;
return CSR_SVR32_ColdCC_SaveList;
}
// Standard calling convention CSRs.
if (TM.isPPC64()) {
if (Subtarget.hasAltivec())
return SaveR2 ? CSR_SVR464_R2_Altivec_SaveList
: CSR_SVR464_Altivec_SaveList;
return SaveR2 ? CSR_SVR464_R2_SaveList
: CSR_SVR464_SaveList;
}
// 32-bit targets.
if (Subtarget.hasAltivec())
return CSR_SVR432_Altivec_SaveList;
else if (Subtarget.hasSPE())
return CSR_SVR432_SPE_SaveList;
return CSR_SVR432_SaveList;
}
const MCPhysReg *
PPCRegisterInfo::getCalleeSavedRegsViaCopy(const MachineFunction *MF) const {
assert(MF && "Invalid MachineFunction pointer.");
const PPCSubtarget &Subtarget = MF->getSubtarget<PPCSubtarget>();
if (Subtarget.isDarwinABI())
return nullptr;
if (!TM.isPPC64())
return nullptr;
if (MF->getFunction().getCallingConv() != CallingConv::CXX_FAST_TLS)
return nullptr;
if (!MF->getInfo<PPCFunctionInfo>()->isSplitCSR())
return nullptr;
// On PPC64, we might need to save r2 (but only if it is not reserved).
bool SaveR2 = !getReservedRegs(*MF).test(PPC::X2);
if (Subtarget.hasAltivec())
return SaveR2
? CSR_SVR464_R2_Altivec_ViaCopy_SaveList
: CSR_SVR464_Altivec_ViaCopy_SaveList;
else
return SaveR2
? CSR_SVR464_R2_ViaCopy_SaveList
: CSR_SVR464_ViaCopy_SaveList;
}
const uint32_t *
PPCRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
CallingConv::ID CC) const {
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
if (CC == CallingConv::AnyReg) {
if (Subtarget.hasVSX())
return CSR_64_AllRegs_VSX_RegMask;
if (Subtarget.hasAltivec())
return CSR_64_AllRegs_Altivec_RegMask;
return CSR_64_AllRegs_RegMask;
}
if (Subtarget.isDarwinABI())
return TM.isPPC64() ? (Subtarget.hasAltivec() ? CSR_Darwin64_Altivec_RegMask
: CSR_Darwin64_RegMask)
: (Subtarget.hasAltivec() ? CSR_Darwin32_Altivec_RegMask
: CSR_Darwin32_RegMask);
if (Subtarget.isAIXABI()) {
assert(!Subtarget.hasAltivec() && "Altivec is not implemented on AIX yet.");
return TM.isPPC64() ? CSR_AIX64_RegMask : CSR_AIX32_RegMask;
}
if (CC == CallingConv::Cold) {
return TM.isPPC64() ? (Subtarget.hasAltivec() ? CSR_SVR64_ColdCC_Altivec_RegMask
: CSR_SVR64_ColdCC_RegMask)
: (Subtarget.hasAltivec() ? CSR_SVR32_ColdCC_Altivec_RegMask
: (Subtarget.hasSPE()
? CSR_SVR32_ColdCC_SPE_RegMask
: CSR_SVR32_ColdCC_RegMask));
}
return TM.isPPC64() ? (Subtarget.hasAltivec() ? CSR_SVR464_Altivec_RegMask
: CSR_SVR464_RegMask)
: (Subtarget.hasAltivec() ? CSR_SVR432_Altivec_RegMask
: (Subtarget.hasSPE()
? CSR_SVR432_SPE_RegMask
: CSR_SVR432_RegMask));
}
const uint32_t*
PPCRegisterInfo::getNoPreservedMask() const {
return CSR_NoRegs_RegMask;
}
void PPCRegisterInfo::adjustStackMapLiveOutMask(uint32_t *Mask) const {
for (unsigned PseudoReg : {PPC::ZERO, PPC::ZERO8, PPC::RM})
Mask[PseudoReg / 32] &= ~(1u << (PseudoReg % 32));
}
BitVector PPCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const PPCFrameLowering *TFI = getFrameLowering(MF);
// The ZERO register is not really a register, but the representation of r0
// when used in instructions that treat r0 as the constant 0.
markSuperRegs(Reserved, PPC::ZERO);
// The FP register is also not really a register, but is the representation
// of the frame pointer register used by ISD::FRAMEADDR.
markSuperRegs(Reserved, PPC::FP);
// The BP register is also not really a register, but is the representation
// of the base pointer register used by setjmp.
markSuperRegs(Reserved, PPC::BP);
// The counter registers must be reserved so that counter-based loops can
// be correctly formed (and the mtctr instructions are not DCE'd).
markSuperRegs(Reserved, PPC::CTR);
markSuperRegs(Reserved, PPC::CTR8);
markSuperRegs(Reserved, PPC::R1);
markSuperRegs(Reserved, PPC::LR);
markSuperRegs(Reserved, PPC::LR8);
markSuperRegs(Reserved, PPC::RM);
if (!Subtarget.isDarwinABI() || !Subtarget.hasAltivec())
markSuperRegs(Reserved, PPC::VRSAVE);
// The SVR4 ABI reserves r2 and r13
if (Subtarget.isSVR4ABI()) {
// We only reserve r2 if we need to use the TOC pointer. If we have no
// explicit uses of the TOC pointer (meaning we're a leaf function with
// no constant-pool loads, etc.) and we have no potential uses inside an
// inline asm block, then we can treat r2 has an ordinary callee-saved
// register.
const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
if (!TM.isPPC64() || FuncInfo->usesTOCBasePtr() || MF.hasInlineAsm())
markSuperRegs(Reserved, PPC::R2); // System-reserved register
markSuperRegs(Reserved, PPC::R13); // Small Data Area pointer register
}
// Always reserve r2 on AIX for now.
// TODO: Make r2 allocatable on AIX/XCOFF for some leaf functions.
if (Subtarget.isAIXABI())
markSuperRegs(Reserved, PPC::R2); // System-reserved register
// On PPC64, r13 is the thread pointer. Never allocate this register.
if (TM.isPPC64())
markSuperRegs(Reserved, PPC::R13);
if (TFI->needsFP(MF))
markSuperRegs(Reserved, PPC::R31);
bool IsPositionIndependent = TM.isPositionIndependent();
if (hasBasePointer(MF)) {
if (Subtarget.is32BitELFABI() && IsPositionIndependent)
markSuperRegs(Reserved, PPC::R29);
else
markSuperRegs(Reserved, PPC::R30);
}
if (Subtarget.is32BitELFABI() && IsPositionIndependent)
markSuperRegs(Reserved, PPC::R30);
// Reserve Altivec registers when Altivec is unavailable.
if (!Subtarget.hasAltivec())
for (TargetRegisterClass::iterator I = PPC::VRRCRegClass.begin(),
IE = PPC::VRRCRegClass.end(); I != IE; ++I)
markSuperRegs(Reserved, *I);
assert(checkAllSuperRegsMarked(Reserved));
return Reserved;
}
bool PPCRegisterInfo::requiresFrameIndexScavenging(const MachineFunction &MF) const {
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const PPCInstrInfo *InstrInfo = Subtarget.getInstrInfo();
const MachineFrameInfo &MFI = MF.getFrameInfo();
const std::vector<CalleeSavedInfo> &Info = MFI.getCalleeSavedInfo();
// If the callee saved info is invalid we have to default to true for safety.
if (!MFI.isCalleeSavedInfoValid())
return true;
// We will require the use of X-Forms because the frame is larger than what
// can be represented in signed 16 bits that fit in the immediate of a D-Form.
// If we need an X-Form then we need a register to store the address offset.
unsigned FrameSize = MFI.getStackSize();
// Signed 16 bits means that the FrameSize cannot be more than 15 bits.
if (FrameSize & ~0x7FFF)
return true;
// The callee saved info is valid so it can be traversed.
// Checking for registers that need saving that do not have load or store
// forms where the address offset is an immediate.
for (unsigned i = 0; i < Info.size(); i++) {
int FrIdx = Info[i].getFrameIdx();
unsigned Reg = Info[i].getReg();
unsigned Opcode = InstrInfo->getStoreOpcodeForSpill(Reg);
if (!MFI.isFixedObjectIndex(FrIdx)) {
// This is not a fixed object. If it requires alignment then we may still
// need to use the XForm.
if (offsetMinAlignForOpcode(Opcode) > 1)
return true;
}
// This is eiher:
// 1) A fixed frame index object which we know are aligned so
// as long as we have a valid DForm/DSForm/DQForm (non XForm) we don't
// need to consider the alignment here.
// 2) A not fixed object but in that case we now know that the min required
// alignment is no more than 1 based on the previous check.
if (InstrInfo->isXFormMemOp(Opcode))
return true;
}
return false;
}
bool PPCRegisterInfo::isCallerPreservedPhysReg(unsigned PhysReg,
const MachineFunction &MF) const {
assert(Register::isPhysicalRegister(PhysReg));
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const MachineFrameInfo &MFI = MF.getFrameInfo();
if (!TM.isPPC64())
return false;
if (!Subtarget.isSVR4ABI())
return false;
if (PhysReg == PPC::X2)
// X2 is guaranteed to be preserved within a function if it is reserved.
// The reason it's reserved is that it's the TOC pointer (and the function
// uses the TOC). In functions where it isn't reserved (i.e. leaf functions
// with no TOC access), we can't claim that it is preserved.
return (getReservedRegs(MF).test(PPC::X2));
if (StackPtrConst && (PhysReg == PPC::X1) && !MFI.hasVarSizedObjects()
&& !MFI.hasOpaqueSPAdjustment())
// The value of the stack pointer does not change within a function after
// the prologue and before the epilogue if there are no dynamic allocations
// and no inline asm which clobbers X1.
return true;
return false;
}
unsigned PPCRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
MachineFunction &MF) const {
const PPCFrameLowering *TFI = getFrameLowering(MF);
const unsigned DefaultSafety = 1;
switch (RC->getID()) {
default:
return 0;
case PPC::G8RC_NOX0RegClassID:
case PPC::GPRC_NOR0RegClassID:
case PPC::SPERCRegClassID:
case PPC::G8RCRegClassID:
case PPC::GPRCRegClassID: {
unsigned FP = TFI->hasFP(MF) ? 1 : 0;
return 32 - FP - DefaultSafety;
}
case PPC::F8RCRegClassID:
case PPC::F4RCRegClassID:
case PPC::QFRCRegClassID:
case PPC::QSRCRegClassID:
case PPC::QBRCRegClassID:
case PPC::VRRCRegClassID:
case PPC::VFRCRegClassID:
case PPC::VSLRCRegClassID:
return 32 - DefaultSafety;
case PPC::VSRCRegClassID:
case PPC::VSFRCRegClassID:
case PPC::VSSRCRegClassID:
return 64 - DefaultSafety;
case PPC::CRRCRegClassID:
return 8 - DefaultSafety;
}
}
const TargetRegisterClass *
PPCRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
const MachineFunction &MF) const {
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
if (Subtarget.hasVSX()) {
// With VSX, we can inflate various sub-register classes to the full VSX
// register set.
// For Power9 we allow the user to enable GPR to vector spills.
// FIXME: Currently limited to spilling GP8RC. A follow on patch will add
// support to spill GPRC.
if (TM.isELFv2ABI()) {
if (Subtarget.hasP9Vector() && EnableGPRToVecSpills &&
RC == &PPC::G8RCRegClass) {
InflateGP8RC++;
return &PPC::SPILLTOVSRRCRegClass;
}
if (RC == &PPC::GPRCRegClass && EnableGPRToVecSpills)
InflateGPRC++;
}
if (RC == &PPC::F8RCRegClass)
return &PPC::VSFRCRegClass;
else if (RC == &PPC::VRRCRegClass)
return &PPC::VSRCRegClass;
else if (RC == &PPC::F4RCRegClass && Subtarget.hasP8Vector())
return &PPC::VSSRCRegClass;
}
return TargetRegisterInfo::getLargestLegalSuperClass(RC, MF);
}
//===----------------------------------------------------------------------===//
// Stack Frame Processing methods
//===----------------------------------------------------------------------===//
/// lowerDynamicAlloc - Generate the code for allocating an object in the
/// current frame. The sequence of code will 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) 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();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
// Get the instruction info.
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
// Determine whether 64-bit pointers are used.
bool LP64 = TM.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.
const PPCFrameLowering *TFI = getFrameLowering(MF);
unsigned TargetAlign = TFI->getStackAlignment();
unsigned MaxAlign = MFI.getMaxAlignment();
assert((maxCallFrameSize & (MaxAlign-1)) == 0 &&
"Maximum call-frame size not sufficiently aligned");
// 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;
Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
if (MaxAlign < TargetAlign && isInt<16>(FrameSize)) {
if (LP64)
BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), Reg)
.addReg(PPC::X31)
.addImm(FrameSize);
else
BuildMI(MBB, II, dl, TII.get(PPC::ADDI), Reg)
.addReg(PPC::R31)
.addImm(FrameSize);
} else if (LP64) {
BuildMI(MBB, II, dl, TII.get(PPC::LD), Reg)
.addImm(0)
.addReg(PPC::X1);
} else {
BuildMI(MBB, II, dl, TII.get(PPC::LWZ), Reg)
.addImm(0)
.addReg(PPC::R1);
}
bool KillNegSizeReg = MI.getOperand(1).isKill();
Register NegSizeReg = MI.getOperand(1).getReg();
// Grow the stack and update the stack pointer link, then determine the
// address of new allocated space.
if (LP64) {
if (MaxAlign > TargetAlign) {
unsigned UnalNegSizeReg = NegSizeReg;
NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
// Unfortunately, there is no andi, only andi., and we can't insert that
// here because we might clobber cr0 while it is live.
BuildMI(MBB, II, dl, TII.get(PPC::LI8), NegSizeReg)
.addImm(~(MaxAlign-1));
unsigned NegSizeReg1 = NegSizeReg;
NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
BuildMI(MBB, II, dl, TII.get(PPC::AND8), NegSizeReg)
.addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
.addReg(NegSizeReg1, RegState::Kill);
KillNegSizeReg = true;
}
BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1)
.addReg(Reg, RegState::Kill)
.addReg(PPC::X1)
.addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
.addReg(PPC::X1)
.addImm(maxCallFrameSize);
} else {
if (MaxAlign > TargetAlign) {
unsigned UnalNegSizeReg = NegSizeReg;
NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
// Unfortunately, there is no andi, only andi., and we can't insert that
// here because we might clobber cr0 while it is live.
BuildMI(MBB, II, dl, TII.get(PPC::LI), NegSizeReg)
.addImm(~(MaxAlign-1));
unsigned NegSizeReg1 = NegSizeReg;
NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
BuildMI(MBB, II, dl, TII.get(PPC::AND), NegSizeReg)
.addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
.addReg(NegSizeReg1, RegState::Kill);
KillNegSizeReg = true;
}
BuildMI(MBB, II, dl, TII.get(PPC::STWUX), PPC::R1)
.addReg(Reg, RegState::Kill)
.addReg(PPC::R1)
.addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg())
.addReg(PPC::R1)
.addImm(maxCallFrameSize);
}
// Discard the DYNALLOC instruction.
MBB.erase(II);
}
void PPCRegisterInfo::lowerDynamicAreaOffset(
MachineBasicBlock::iterator II) 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();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
// Get the instruction info.
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
unsigned maxCallFrameSize = MFI.getMaxCallFrameSize();
bool is64Bit = TM.isPPC64();
DebugLoc dl = MI.getDebugLoc();
BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LI8 : PPC::LI),
MI.getOperand(0).getReg())
.addImm(maxCallFrameSize);
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) const {
// Get the instruction.
MachineInstr &MI = *II; // ; SPILL_CR <SrcReg>, <offset>
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
DebugLoc dl = MI.getDebugLoc();
bool LP64 = TM.isPPC64();
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
Register SrcReg = MI.getOperand(0).getReg();
// We need to store the CR in the low 4-bits of the saved value. First, issue
// an MFOCRF to save all of the CRBits and, if needed, kill the SrcReg.
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), 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) {
unsigned Reg1 = Reg;
Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
// rlwinm rA, rA, ShiftBits, 0, 31.
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
.addReg(Reg1, RegState::Kill)
.addImm(getEncodingValue(SrcReg) * 4)
.addImm(0)
.addImm(31);
}
addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
.addReg(Reg, RegState::Kill),
FrameIndex);
// Discard the pseudo instruction.
MBB.erase(II);
}
void PPCRegisterInfo::lowerCRRestore(MachineBasicBlock::iterator II,
unsigned FrameIndex) const {
// Get the instruction.
MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CR <offset>
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
DebugLoc dl = MI.getDebugLoc();
bool LP64 = TM.isPPC64();
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
Register DestReg = MI.getOperand(0).getReg();
assert(MI.definesRegister(DestReg) &&
"RESTORE_CR does not define its destination");
addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
Reg), FrameIndex);
// 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 Reg1 = Reg;
Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
unsigned ShiftBits = getEncodingValue(DestReg)*4;
// rlwinm r11, r11, 32-ShiftBits, 0, 31.
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
.addReg(Reg1, RegState::Kill).addImm(32-ShiftBits).addImm(0)
.addImm(31);
}
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF), DestReg)
.addReg(Reg, RegState::Kill);
// Discard the pseudo instruction.
MBB.erase(II);
}
void PPCRegisterInfo::lowerCRBitSpilling(MachineBasicBlock::iterator II,
unsigned FrameIndex) const {
// Get the instruction.
MachineInstr &MI = *II; // ; SPILL_CRBIT <SrcReg>, <offset>
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
const TargetRegisterInfo* TRI = Subtarget.getRegisterInfo();
DebugLoc dl = MI.getDebugLoc();
bool LP64 = TM.isPPC64();
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
Register SrcReg = MI.getOperand(0).getReg();
// Search up the BB to find the definition of the CR bit.
MachineBasicBlock::reverse_iterator Ins = MI;
MachineBasicBlock::reverse_iterator Rend = MBB.rend();
++Ins;
unsigned CRBitSpillDistance = 0;
bool SeenUse = false;
for (; Ins != Rend; ++Ins) {
// Definition found.
if (Ins->modifiesRegister(SrcReg, TRI))
break;
// Use found.
if (Ins->readsRegister(SrcReg, TRI))
SeenUse = true;
// Unable to find CR bit definition within maximum search distance.
if (CRBitSpillDistance == MaxCRBitSpillDist) {
Ins = MI;
break;
}
// Skip debug instructions when counting CR bit spill distance.
if (!Ins->isDebugInstr())
CRBitSpillDistance++;
}
// Unable to find the definition of the CR bit in the MBB.
if (Ins == MBB.rend())
Ins = MI;
bool SpillsKnownBit = false;
// There is no need to extract the CR bit if its value is already known.
switch (Ins->getOpcode()) {
case PPC::CRUNSET:
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LI8 : PPC::LI), Reg)
.addImm(0);
SpillsKnownBit = true;
break;
case PPC::CRSET:
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LIS8 : PPC::LIS), Reg)
.addImm(-32768);
SpillsKnownBit = true;
break;
default:
// On Power9, we can use SETB to extract the LT bit. This only works for
// the LT bit since SETB produces -1/1/0 for LT/GT/<neither>. So the value
// of the bit we care about (32-bit sign bit) will be set to the value of
// the LT bit (regardless of the other bits in the CR field).
if (Subtarget.isISA3_0()) {
if (SrcReg == PPC::CR0LT || SrcReg == PPC::CR1LT ||
SrcReg == PPC::CR2LT || SrcReg == PPC::CR3LT ||
SrcReg == PPC::CR4LT || SrcReg == PPC::CR5LT ||
SrcReg == PPC::CR6LT || SrcReg == PPC::CR7LT) {
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::SETB8 : PPC::SETB), Reg)
.addReg(getCRFromCRBit(SrcReg), RegState::Undef);
break;
}
}
// We need to move the CR field that contains the CR bit we are spilling.
// The super register may not be explicitly defined (i.e. it can be defined
// by a CR-logical that only defines the subreg) so we state that the CR
// field is undef. Also, in order to preserve the kill flag on the CR bit,
// we add it as an implicit use.
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), Reg)
.addReg(getCRFromCRBit(SrcReg), RegState::Undef)
.addReg(SrcReg,
RegState::Implicit | getKillRegState(MI.getOperand(0).isKill()));
// If the saved register wasn't CR0LT, shift the bits left so that the bit
// to store is the first one. Mask all but that bit.
unsigned Reg1 = Reg;
Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
// rlwinm rA, rA, ShiftBits, 0, 0.
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
.addReg(Reg1, RegState::Kill)
.addImm(getEncodingValue(SrcReg))
.addImm(0).addImm(0);
}
addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
.addReg(Reg, RegState::Kill),
FrameIndex);
bool KillsCRBit = MI.killsRegister(SrcReg, TRI);
// Discard the pseudo instruction.
MBB.erase(II);
if (SpillsKnownBit && KillsCRBit && !SeenUse) {
Ins->setDesc(TII.get(PPC::UNENCODED_NOP));
Ins->RemoveOperand(0);
}
}
void PPCRegisterInfo::lowerCRBitRestore(MachineBasicBlock::iterator II,
unsigned FrameIndex) const {
// Get the instruction.
MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CRBIT <offset>
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
DebugLoc dl = MI.getDebugLoc();
bool LP64 = TM.isPPC64();
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
Register DestReg = MI.getOperand(0).getReg();
assert(MI.definesRegister(DestReg) &&
"RESTORE_CRBIT does not define its destination");
addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
Reg), FrameIndex);
BuildMI(MBB, II, dl, TII.get(TargetOpcode::IMPLICIT_DEF), DestReg);
Register RegO = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), RegO)
.addReg(getCRFromCRBit(DestReg));
unsigned ShiftBits = getEncodingValue(DestReg);
// rlwimi r11, r10, 32-ShiftBits, ..., ...
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWIMI8 : PPC::RLWIMI), RegO)
.addReg(RegO, RegState::Kill)
.addReg(Reg, RegState::Kill)
.addImm(ShiftBits ? 32 - ShiftBits : 0)
.addImm(ShiftBits)
.addImm(ShiftBits);
BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF),
getCRFromCRBit(DestReg))
.addReg(RegO, RegState::Kill)
// Make sure we have a use dependency all the way through this
// sequence of instructions. We can't have the other bits in the CR
// modified in between the mfocrf and the mtocrf.
.addReg(getCRFromCRBit(DestReg), RegState::Implicit);
// Discard the pseudo instruction.
MBB.erase(II);
}
void PPCRegisterInfo::lowerVRSAVESpilling(MachineBasicBlock::iterator II,
unsigned FrameIndex) const {
// Get the instruction.
MachineInstr &MI = *II; // ; SPILL_VRSAVE <SrcReg>, <offset>
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
DebugLoc dl = MI.getDebugLoc();
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
Register Reg = MF.getRegInfo().createVirtualRegister(GPRC);
Register SrcReg = MI.getOperand(0).getReg();
BuildMI(MBB, II, dl, TII.get(PPC::MFVRSAVEv), Reg)
.addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
addFrameReference(
BuildMI(MBB, II, dl, TII.get(PPC::STW)).addReg(Reg, RegState::Kill),
FrameIndex);
// Discard the pseudo instruction.
MBB.erase(II);
}
void PPCRegisterInfo::lowerVRSAVERestore(MachineBasicBlock::iterator II,
unsigned FrameIndex) const {
// Get the instruction.
MachineInstr &MI = *II; // ; <DestReg> = RESTORE_VRSAVE <offset>
// Get the instruction's basic block.
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
DebugLoc dl = MI.getDebugLoc();
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
Register Reg = MF.getRegInfo().createVirtualRegister(GPRC);
Register DestReg = MI.getOperand(0).getReg();
assert(MI.definesRegister(DestReg) &&
"RESTORE_VRSAVE does not define its destination");
addFrameReference(BuildMI(MBB, II, dl, TII.get(PPC::LWZ),
Reg), FrameIndex);
BuildMI(MBB, II, dl, TII.get(PPC::MTVRSAVEv), DestReg)
.addReg(Reg, RegState::Kill);
// Discard the pseudo instruction.
MBB.erase(II);
}
bool PPCRegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
unsigned Reg, int &FrameIdx) const {
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
// For the nonvolatile condition registers (CR2, CR3, CR4) in an SVR4
// ABI, return true to prevent allocating an additional frame slot.
// For 64-bit, the CR save area is at SP+8; the value of FrameIdx = 0
// is arbitrary and will be subsequently ignored. For 32-bit, we have
// previously created the stack slot if needed, so return its FrameIdx.
if (Subtarget.isSVR4ABI() && PPC::CR2 <= Reg && Reg <= PPC::CR4) {
if (TM.isPPC64())
FrameIdx = 0;
else {
const PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
FrameIdx = FI->getCRSpillFrameIndex();
}
return true;
}
return false;
}
// If the offset must be a multiple of some value, return what that value is.
static unsigned offsetMinAlignForOpcode(unsigned OpC) {
switch (OpC) {
default:
return 1;
case PPC::LWA:
case PPC::LWA_32:
case PPC::LD:
case PPC::LDU:
case PPC::STD:
case PPC::STDU:
case PPC::DFLOADf32:
case PPC::DFLOADf64:
case PPC::DFSTOREf32:
case PPC::DFSTOREf64:
case PPC::LXSD:
case PPC::LXSSP:
case PPC::STXSD:
case PPC::STXSSP:
return 4;
case PPC::EVLDD:
case PPC::EVSTDD:
return 8;
case PPC::LXV:
case PPC::STXV:
return 16;
}
}
// If the offset must be a multiple of some value, return what that value is.
static unsigned offsetMinAlign(const MachineInstr &MI) {
unsigned OpC = MI.getOpcode();
return offsetMinAlignForOpcode(OpC);
}
// Return the OffsetOperandNo given the FIOperandNum (and the instruction).
static unsigned getOffsetONFromFION(const MachineInstr &MI,
unsigned FIOperandNum) {
// Take into account whether it's an add or mem instruction
unsigned OffsetOperandNo = (FIOperandNum == 2) ? 1 : 2;
if (MI.isInlineAsm())
OffsetOperandNo = FIOperandNum - 1;
else if (MI.getOpcode() == TargetOpcode::STACKMAP ||
MI.getOpcode() == TargetOpcode::PATCHPOINT)
OffsetOperandNo = FIOperandNum + 1;
return OffsetOperandNo;
}
void
PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, unsigned FIOperandNum,
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();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
// Get the instruction info.
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
// Get the frame info.
MachineFrameInfo &MFI = MF.getFrameInfo();
DebugLoc dl = MI.getDebugLoc();
unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
// Get the frame index.
int FrameIndex = MI.getOperand(FIOperandNum).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();
if ((OpC == PPC::DYNAREAOFFSET || OpC == PPC::DYNAREAOFFSET8)) {
lowerDynamicAreaOffset(II);
return;
}
// Special case for dynamic alloca.
if (FPSI && FrameIndex == FPSI &&
(OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) {
lowerDynamicAlloc(II);
return;
}
// Special case for pseudo-ops SPILL_CR and RESTORE_CR, etc.
if (OpC == PPC::SPILL_CR) {
lowerCRSpilling(II, FrameIndex);
return;
} else if (OpC == PPC::RESTORE_CR) {
lowerCRRestore(II, FrameIndex);
return;
} else if (OpC == PPC::SPILL_CRBIT) {
lowerCRBitSpilling(II, FrameIndex);
return;
} else if (OpC == PPC::RESTORE_CRBIT) {
lowerCRBitRestore(II, FrameIndex);
return;
} else if (OpC == PPC::SPILL_VRSAVE) {
lowerVRSAVESpilling(II, FrameIndex);
return;
} else if (OpC == PPC::RESTORE_VRSAVE) {
lowerVRSAVERestore(II, FrameIndex);
return;
}
// Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
MI.getOperand(FIOperandNum).ChangeToRegister(
FrameIndex < 0 ? getBaseRegister(MF) : getFrameRegister(MF), false);
// If the instruction is not present in ImmToIdxMap, then it has no immediate
// form (and must be r+r).
bool noImmForm = !MI.isInlineAsm() && OpC != TargetOpcode::STACKMAP &&
OpC != TargetOpcode::PATCHPOINT && !ImmToIdxMap.count(OpC);
// Now add the frame object offset to the offset from r1.
int Offset = MFI.getObjectOffset(FrameIndex);
Offset += MI.getOperand(OffsetOperandNo).getImm();
// 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().hasFnAttribute(Attribute::Naked)) {
if (!(hasBasePointer(MF) && FrameIndex < 0))
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.
assert(OpC != PPC::DBG_VALUE &&
"This should be handled in a target-independent way");
bool OffsetFitsMnemonic = (OpC == PPC::EVSTDD || OpC == PPC::EVLDD) ?
isUInt<8>(Offset) :
isInt<16>(Offset);
if (!noImmForm && ((OffsetFitsMnemonic &&
((Offset % offsetMinAlign(MI)) == 0)) ||
OpC == TargetOpcode::STACKMAP ||
OpC == TargetOpcode::PATCHPOINT)) {
MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
return;
}
// The offset doesn't fit into a single register, scavenge one to build the
// offset in.
bool is64Bit = TM.isPPC64();
const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
const TargetRegisterClass *RC = is64Bit ? G8RC : GPRC;
unsigned SRegHi = MF.getRegInfo().createVirtualRegister(RC),
SReg = MF.getRegInfo().createVirtualRegister(RC);
// Insert a set of rA with the full offset value before the ld, st, or add
if (isInt<16>(Offset))
BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LI8 : PPC::LI), SReg)
.addImm(Offset);
else {
BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LIS8 : PPC::LIS), SRegHi)
.addImm(Offset >> 16);
BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::ORI8 : PPC::ORI), SReg)
.addReg(SRegHi, 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 (noImmForm)
OperandBase = 1;
else if (OpC != TargetOpcode::INLINEASM &&
OpC != TargetOpcode::INLINEASM_BR) {
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;
}
Register StackReg = MI.getOperand(FIOperandNum).getReg();
MI.getOperand(OperandBase).ChangeToRegister(StackReg, false);
MI.getOperand(OperandBase + 1).ChangeToRegister(SReg, false, false, true);
}
Register PPCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
const PPCFrameLowering *TFI = getFrameLowering(MF);
if (!TM.isPPC64())
return TFI->hasFP(MF) ? PPC::R31 : PPC::R1;
else
return TFI->hasFP(MF) ? PPC::X31 : PPC::X1;
}
Register PPCRegisterInfo::getBaseRegister(const MachineFunction &MF) const {
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
if (!hasBasePointer(MF))
return getFrameRegister(MF);
if (TM.isPPC64())
return PPC::X30;
if (Subtarget.isSVR4ABI() && TM.isPositionIndependent())
return PPC::R29;
return PPC::R30;
}
bool PPCRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
if (!EnableBasePointer)
return false;
if (AlwaysBasePointer)
return true;
// If we need to realign the stack, then the stack pointer can no longer
// serve as an offset into the caller's stack space. As a result, we need a
// base pointer.
return needsStackRealignment(MF);
}
/// Returns true if the instruction's frame index
/// reference would be better served by a base register other than FP
/// or SP. Used by LocalStackFrameAllocation to determine which frame index
/// references it should create new base registers for.
bool PPCRegisterInfo::
needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const {
assert(Offset < 0 && "Local offset must be negative");
// It's the load/store FI references that cause issues, as it can be difficult
// to materialize the offset if it won't fit in the literal field. Estimate
// based on the size of the local frame and some conservative assumptions
// about the rest of the stack frame (note, this is pre-regalloc, so
// we don't know everything for certain yet) whether this offset is likely
// to be out of range of the immediate. Return true if so.
// We only generate virtual base registers for loads and stores that have
// an r+i form. Return false for everything else.
unsigned OpC = MI->getOpcode();
if (!ImmToIdxMap.count(OpC))
return false;
// Don't generate a new virtual base register just to add zero to it.
if ((OpC == PPC::ADDI || OpC == PPC::ADDI8) &&
MI->getOperand(2).getImm() == 0)
return false;
MachineBasicBlock &MBB = *MI->getParent();
MachineFunction &MF = *MBB.getParent();
const PPCFrameLowering *TFI = getFrameLowering(MF);
unsigned StackEst = TFI->determineFrameLayout(MF, true);
// If we likely don't need a stack frame, then we probably don't need a
// virtual base register either.
if (!StackEst)
return false;
// Estimate an offset from the stack pointer.
// The incoming offset is relating to the SP at the start of the function,
// but when we access the local it'll be relative to the SP after local
// allocation, so adjust our SP-relative offset by that allocation size.
Offset += StackEst;
// The frame pointer will point to the end of the stack, so estimate the
// offset as the difference between the object offset and the FP location.
return !isFrameOffsetLegal(MI, getBaseRegister(MF), Offset);
}
/// Insert defining instruction(s) for BaseReg to
/// be a pointer to FrameIdx at the beginning of the basic block.
void PPCRegisterInfo::
materializeFrameBaseRegister(MachineBasicBlock *MBB,
unsigned BaseReg, int FrameIdx,
int64_t Offset) const {
unsigned ADDriOpc = TM.isPPC64() ? PPC::ADDI8 : PPC::ADDI;
MachineBasicBlock::iterator Ins = MBB->begin();
DebugLoc DL; // Defaults to "unknown"
if (Ins != MBB->end())
DL = Ins->getDebugLoc();
const MachineFunction &MF = *MBB->getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
const MCInstrDesc &MCID = TII.get(ADDriOpc);
MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
MRI.constrainRegClass(BaseReg, TII.getRegClass(MCID, 0, this, MF));
BuildMI(*MBB, Ins, DL, MCID, BaseReg)
.addFrameIndex(FrameIdx).addImm(Offset);
}
void PPCRegisterInfo::resolveFrameIndex(MachineInstr &MI, unsigned BaseReg,
int64_t Offset) const {
unsigned FIOperandNum = 0;
while (!MI.getOperand(FIOperandNum).isFI()) {
++FIOperandNum;
assert(FIOperandNum < MI.getNumOperands() &&
"Instr doesn't have FrameIndex operand!");
}
MI.getOperand(FIOperandNum).ChangeToRegister(BaseReg, false);
unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
Offset += MI.getOperand(OffsetOperandNo).getImm();
MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
const MCInstrDesc &MCID = MI.getDesc();
MachineRegisterInfo &MRI = MF.getRegInfo();
MRI.constrainRegClass(BaseReg,
TII.getRegClass(MCID, FIOperandNum, this, MF));
}
bool PPCRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
unsigned BaseReg,
int64_t Offset) const {
unsigned FIOperandNum = 0;
while (!MI->getOperand(FIOperandNum).isFI()) {
++FIOperandNum;
assert(FIOperandNum < MI->getNumOperands() &&
"Instr doesn't have FrameIndex operand!");
}
unsigned OffsetOperandNo = getOffsetONFromFION(*MI, FIOperandNum);
Offset += MI->getOperand(OffsetOperandNo).getImm();
return MI->getOpcode() == PPC::DBG_VALUE || // DBG_VALUE is always Reg+Imm
MI->getOpcode() == TargetOpcode::STACKMAP ||
MI->getOpcode() == TargetOpcode::PATCHPOINT ||
(isInt<16>(Offset) && (Offset % offsetMinAlign(*MI)) == 0);
}