#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/CodeGen/VirtRegMap.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Function.h"
-#include "llvm/LLVMContext.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/LLVMContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
+#define DEBUG_TYPE "arm-register-info"
+
#define GET_REGINFO_TARGET_DESC
#include "ARMGenRegisterInfo.inc"
using namespace llvm;
-ARMBaseRegisterInfo::ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii,
- const ARMSubtarget &sti)
- : ARMGenRegisterInfo(ARM::LR, 0, 0, ARM::PC), TII(tii), STI(sti),
- FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11),
- BasePtr(ARM::R6) {
+ARMBaseRegisterInfo::ARMBaseRegisterInfo()
+ : ARMGenRegisterInfo(ARM::LR, 0, 0, ARM::PC), BasePtr(ARM::R6) {}
+
+static unsigned getFramePointerReg(const ARMSubtarget &STI) {
+ if (STI.isTargetMachO()) {
+ if (STI.isTargetDarwin() || STI.isThumb1Only())
+ return ARM::R7;
+ else
+ return ARM::R11;
+ } else if (STI.isTargetWindows())
+ return ARM::R11;
+ else // ARM EABI
+ return STI.isThumb() ? ARM::R7 : ARM::R11;
}
-const uint16_t*
+const MCPhysReg*
ARMBaseRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
- bool ghcCall = false;
-
- if (MF) {
- const Function *F = MF->getFunction();
- ghcCall = (F ? F->getCallingConv() == CallingConv::GHC : false);
- }
-
- if (ghcCall) {
- return CSR_GHC_SaveList;
- }
- else {
- return (STI.isTargetIOS() && !STI.isAAPCS_ABI())
- ? CSR_iOS_SaveList : CSR_AAPCS_SaveList;
+ const ARMSubtarget &STI = MF->getSubtarget<ARMSubtarget>();
+ const MCPhysReg *RegList =
+ STI.isTargetDarwin() ? CSR_iOS_SaveList : CSR_AAPCS_SaveList;
+
+ const Function *F = MF->getFunction();
+ if (F->getCallingConv() == CallingConv::GHC) {
+ // GHC set of callee saved regs is empty as all those regs are
+ // used for passing STG regs around
+ return CSR_NoRegs_SaveList;
+ } else if (F->hasFnAttribute("interrupt")) {
+ if (STI.isMClass()) {
+ // M-class CPUs have hardware which saves the registers needed to allow a
+ // function conforming to the AAPCS to function as a handler.
+ return CSR_AAPCS_SaveList;
+ } else if (F->getFnAttribute("interrupt").getValueAsString() == "FIQ") {
+ // Fast interrupt mode gives the handler a private copy of R8-R14, so less
+ // need to be saved to restore user-mode state.
+ return CSR_FIQ_SaveList;
+ } else {
+ // Generally only R13-R14 (i.e. SP, LR) are automatically preserved by
+ // exception handling.
+ return CSR_GenericInt_SaveList;
+ }
}
+
+ return RegList;
}
-const uint32_t*
-ARMBaseRegisterInfo::getCallPreservedMask(CallingConv::ID) const {
- return (STI.isTargetIOS() && !STI.isAAPCS_ABI())
- ? CSR_iOS_RegMask : CSR_AAPCS_RegMask;
+const uint32_t *
+ARMBaseRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
+ CallingConv::ID CC) const {
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ if (CC == CallingConv::GHC)
+ // This is academic becase all GHC calls are (supposed to be) tail calls
+ return CSR_NoRegs_RegMask;
+ return STI.isTargetDarwin() ? CSR_iOS_RegMask : CSR_AAPCS_RegMask;
}
const uint32_t*
return CSR_NoRegs_RegMask;
}
+const uint32_t *
+ARMBaseRegisterInfo::getThisReturnPreservedMask(const MachineFunction &MF,
+ CallingConv::ID CC) const {
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ // This should return a register mask that is the same as that returned by
+ // getCallPreservedMask but that additionally preserves the register used for
+ // the first i32 argument (which must also be the register used to return a
+ // single i32 return value)
+ //
+ // In case that the calling convention does not use the same register for
+ // both or otherwise does not want to enable this optimization, the function
+ // should return NULL
+ if (CC == CallingConv::GHC)
+ // This is academic becase all GHC calls are (supposed to be) tail calls
+ return nullptr;
+ return STI.isTargetDarwin() ? CSR_iOS_ThisReturn_RegMask
+ : CSR_AAPCS_ThisReturn_RegMask;
+}
+
BitVector ARMBaseRegisterInfo::
getReservedRegs(const MachineFunction &MF) const {
- const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
// FIXME: avoid re-calculating this every time.
BitVector Reserved(getNumRegs());
Reserved.set(ARM::SP);
Reserved.set(ARM::PC);
Reserved.set(ARM::FPSCR);
+ Reserved.set(ARM::APSR_NZCV);
if (TFI->hasFP(MF))
- Reserved.set(FramePtr);
+ Reserved.set(getFramePointerReg(STI));
if (hasBasePointer(MF))
Reserved.set(BasePtr);
// Some targets reserve R9.
return Reserved;
}
-const TargetRegisterClass*
-ARMBaseRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC)
- const {
+const TargetRegisterClass *
+ARMBaseRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
+ const MachineFunction &) const {
const TargetRegisterClass *Super = RC;
TargetRegisterClass::sc_iterator I = RC->getSuperClasses();
do {
const TargetRegisterClass *
ARMBaseRegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
if (RC == &ARM::CCRRegClass)
- return 0; // Can't copy CCR registers.
+ return &ARM::rGPRRegClass; // Can't copy CCR registers.
return RC;
}
unsigned
ARMBaseRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
MachineFunction &MF) const {
- const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
switch (RC->getID()) {
default:
ArrayRef<MCPhysReg> Order,
SmallVectorImpl<MCPhysReg> &Hints,
const MachineFunction &MF,
- const VirtRegMap *VRM) const {
+ const VirtRegMap *VRM,
+ const LiveRegMatrix *Matrix) const {
const MachineRegisterInfo &MRI = MF.getRegInfo();
std::pair<unsigned, unsigned> Hint = MRI.getRegAllocationHint(VirtReg);
// This register should preferably be even (Odd == 0) or odd (Odd == 1).
// Check if the other part of the pair has already been assigned, and provide
// the paired register as the first hint.
+ unsigned Paired = Hint.second;
+ if (Paired == 0)
+ return;
+
unsigned PairedPhys = 0;
- if (VRM && VRM->hasPhys(Hint.second)) {
- PairedPhys = getPairedGPR(VRM->getPhys(Hint.second), Odd, this);
- if (PairedPhys && MRI.isReserved(PairedPhys))
- PairedPhys = 0;
+ if (TargetRegisterInfo::isPhysicalRegister(Paired)) {
+ PairedPhys = Paired;
+ } else if (VRM && VRM->hasPhys(Paired)) {
+ PairedPhys = getPairedGPR(VRM->getPhys(Paired), Odd, this);
}
// First prefer the paired physreg.
- if (PairedPhys)
+ if (PairedPhys &&
+ std::find(Order.begin(), Order.end(), PairedPhys) != Order.end())
Hints.push_back(PairedPhys);
// Then prefer even or odd registers.
}
void
-ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg,
+ARMBaseRegisterInfo::updateRegAllocHint(unsigned Reg, unsigned NewReg,
MachineFunction &MF) const {
MachineRegisterInfo *MRI = &MF.getRegInfo();
std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(Reg);
// change.
unsigned OtherReg = Hint.second;
Hint = MRI->getRegAllocationHint(OtherReg);
- if (Hint.second == Reg)
- // Make sure the pair has not already divorced.
+ // Make sure the pair has not already divorced.
+ if (Hint.second == Reg) {
MRI->setRegAllocationHint(OtherReg, Hint.first, NewReg);
- }
-}
-
-bool
-ARMBaseRegisterInfo::avoidWriteAfterWrite(const TargetRegisterClass *RC) const {
- // CortexA9 has a Write-after-write hazard for NEON registers.
- if (!STI.isLikeA9())
- return false;
-
- switch (RC->getID()) {
- case ARM::DPRRegClassID:
- case ARM::DPR_8RegClassID:
- case ARM::DPR_VFP2RegClassID:
- case ARM::QPRRegClassID:
- case ARM::QPR_8RegClassID:
- case ARM::QPR_VFP2RegClassID:
- case ARM::SPRRegClassID:
- case ARM::SPR_8RegClassID:
- // Avoid reusing S, D, and Q registers.
- // Don't increase register pressure for QQ and QQQQ.
- return true;
- default:
- return false;
+ if (TargetRegisterInfo::isVirtualRegister(NewReg))
+ MRI->setRegAllocationHint(NewReg,
+ Hint.first == (unsigned)ARMRI::RegPairOdd ? ARMRI::RegPairEven
+ : ARMRI::RegPairOdd, OtherReg);
+ }
}
}
bool ARMBaseRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
// When outgoing call frames are so large that we adjust the stack pointer
// around the call, we can no longer use the stack pointer to reach the
bool ARMBaseRegisterInfo::canRealignStack(const MachineFunction &MF) const {
const MachineRegisterInfo *MRI = &MF.getRegInfo();
const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
// We can't realign the stack if:
// 1. Dynamic stack realignment is explicitly disabled,
// 2. This is a Thumb1 function (it's not useful, so we don't bother), or
// 3. There are VLAs in the function and the base pointer is disabled.
- if (!MF.getTarget().Options.RealignStack)
+ if (!TargetRegisterInfo::canRealignStack(MF))
return false;
if (AFI->isThumb1OnlyFunction())
return false;
// Stack realignment requires a frame pointer. If we already started
// register allocation with frame pointer elimination, it is too late now.
- if (!MRI->canReserveReg(FramePtr))
+ if (!MRI->canReserveReg(getFramePointerReg(MF.getSubtarget<ARMSubtarget>())))
return false;
// We may also need a base pointer if there are dynamic allocas or stack
// pointer adjustments around calls.
- if (MF.getTarget().getFrameLowering()->hasReservedCallFrame(MF))
+ if (TFI->hasReservedCallFrame(MF))
return true;
// A base pointer is required and allowed. Check that it isn't too late to
// reserve it.
return MRI->canReserveReg(BasePtr);
}
-bool ARMBaseRegisterInfo::
-needsStackRealignment(const MachineFunction &MF) const {
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- const Function *F = MF.getFunction();
- unsigned StackAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
- bool requiresRealignment =
- ((MFI->getMaxAlignment() > StackAlign) ||
- F->getFnAttributes().hasAttribute(Attribute::StackAlignment));
-
- return requiresRealignment && canRealignStack(MF);
-}
-
bool ARMBaseRegisterInfo::
cannotEliminateFrame(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
unsigned
ARMBaseRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
- const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+ const ARMSubtarget &STI = MF.getSubtarget<ARMSubtarget>();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
if (TFI->hasFP(MF))
- return FramePtr;
+ return getFramePointerReg(STI);
return ARM::SP;
}
-unsigned ARMBaseRegisterInfo::getEHExceptionRegister() const {
- llvm_unreachable("What is the exception register");
-}
-
-unsigned ARMBaseRegisterInfo::getEHHandlerRegister() const {
- llvm_unreachable("What is the exception handler register");
-}
-
/// emitLoadConstPool - Emits a load from constpool to materialize the
/// specified immediate.
void ARMBaseRegisterInfo::
ARMCC::CondCodes Pred,
unsigned PredReg, unsigned MIFlags) const {
MachineFunction &MF = *MBB.getParent();
+ const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
MachineConstantPool *ConstantPool = MF.getConstantPool();
const Constant *C =
ConstantInt::get(Type::getInt32Ty(MF.getFunction()->getContext()), Val);
return true;
}
-static void
-emitSPUpdate(bool isARM,
- MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
- DebugLoc dl, const ARMBaseInstrInfo &TII,
- int NumBytes,
- ARMCC::CondCodes Pred = ARMCC::AL, unsigned PredReg = 0) {
- if (isARM)
- emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
- Pred, PredReg, TII);
- else
- emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
- Pred, PredReg, TII);
-}
-
-
-void ARMBaseRegisterInfo::
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I) const {
- const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
- if (!TFI->hasReservedCallFrame(MF)) {
- // If we have alloca, convert as follows:
- // ADJCALLSTACKDOWN -> sub, sp, sp, amount
- // ADJCALLSTACKUP -> add, sp, sp, amount
- MachineInstr *Old = I;
- DebugLoc dl = Old->getDebugLoc();
- unsigned Amount = Old->getOperand(0).getImm();
- if (Amount != 0) {
- // We need to keep the stack aligned properly. To do this, we round the
- // amount of space needed for the outgoing arguments up to the next
- // alignment boundary.
- unsigned Align = TFI->getStackAlignment();
- Amount = (Amount+Align-1)/Align*Align;
-
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- assert(!AFI->isThumb1OnlyFunction() &&
- "This eliminateCallFramePseudoInstr does not support Thumb1!");
- bool isARM = !AFI->isThumbFunction();
-
- // Replace the pseudo instruction with a new instruction...
- unsigned Opc = Old->getOpcode();
- int PIdx = Old->findFirstPredOperandIdx();
- ARMCC::CondCodes Pred = (PIdx == -1)
- ? ARMCC::AL : (ARMCC::CondCodes)Old->getOperand(PIdx).getImm();
- if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
- // Note: PredReg is operand 2 for ADJCALLSTACKDOWN.
- unsigned PredReg = Old->getOperand(2).getReg();
- emitSPUpdate(isARM, MBB, I, dl, TII, -Amount, Pred, PredReg);
- } else {
- // Note: PredReg is operand 3 for ADJCALLSTACKUP.
- unsigned PredReg = Old->getOperand(3).getReg();
- assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
- emitSPUpdate(isARM, MBB, I, dl, TII, Amount, Pred, PredReg);
- }
- }
- }
- MBB.erase(I);
-}
-
int64_t ARMBaseRegisterInfo::
getFrameIndexInstrOffset(const MachineInstr *MI, int Idx) const {
const MCInstrDesc &Desc = MI->getDesc();
// Note that the incoming offset is based on the SP value at function entry,
// so it'll be negative.
MachineFunction &MF = *MI->getParent()->getParent();
- const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
// 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 = -Offset;
Offset += MFI->getLocalFrameSize();
// Assume that we'll have at least some spill slots allocated.
// FIXME: This is a total SWAG number. We should run some statistics
// and pick a real one.
Offset += 128; // 128 bytes of spill slots
- // If there is a frame pointer, try using it.
+ // If there's a frame pointer and the addressing mode allows it, try using it.
// The FP is only available if there is no dynamic realignment. We
// don't know for sure yet whether we'll need that, so we guess based
// on whether there are any local variables that would trigger it.
unsigned StackAlign = TFI->getStackAlignment();
- if (TFI->hasFP(MF) &&
+ if (TFI->hasFP(MF) &&
!((MFI->getLocalFrameMaxAlign() > StackAlign) && canRealignStack(MF))) {
- if (isFrameOffsetLegal(MI, FPOffset))
+ if (isFrameOffsetLegal(MI, getFrameRegister(MF), FPOffset))
return false;
}
// If we can reference via the stack pointer, try that.
// to only disallow SP relative references in the live range of
// the VLA(s). In practice, it's unclear how much difference that
// would make, but it may be worth doing.
- if (!MFI->hasVarSizedObjects() && isFrameOffsetLegal(MI, Offset))
+ if (!MFI->hasVarSizedObjects() && isFrameOffsetLegal(MI, ARM::SP, Offset))
return false;
// The offset likely isn't legal, we want to allocate a virtual base register.
int64_t Offset) const {
ARMFunctionInfo *AFI = MBB->getParent()->getInfo<ARMFunctionInfo>();
unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri :
- (AFI->isThumb1OnlyFunction() ? ARM::tADDrSPi : ARM::t2ADDri);
+ (AFI->isThumb1OnlyFunction() ? ARM::tADDframe : ARM::t2ADDri);
MachineBasicBlock::iterator Ins = MBB->begin();
DebugLoc DL; // Defaults to "unknown"
if (Ins != MBB->end())
DL = Ins->getDebugLoc();
- const MCInstrDesc &MCID = TII.get(ADDriOpc);
- MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
const MachineFunction &MF = *MBB->getParent();
+ MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
+ const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
+ const MCInstrDesc &MCID = TII.get(ADDriOpc);
MRI.constrainRegClass(BaseReg, TII.getRegClass(MCID, 0, this, MF));
- MachineInstrBuilder MIB = AddDefaultPred(BuildMI(*MBB, Ins, DL, MCID, BaseReg)
- .addFrameIndex(FrameIdx).addImm(Offset));
+ MachineInstrBuilder MIB = BuildMI(*MBB, Ins, DL, MCID, BaseReg)
+ .addFrameIndex(FrameIdx).addImm(Offset);
if (!AFI->isThumb1OnlyFunction())
- AddDefaultCC(MIB);
+ AddDefaultCC(AddDefaultPred(MIB));
}
-void
-ARMBaseRegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I,
- unsigned BaseReg, int64_t Offset) const {
- MachineInstr &MI = *I;
+void ARMBaseRegisterInfo::resolveFrameIndex(MachineInstr &MI, unsigned BaseReg,
+ int64_t Offset) const {
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo *>(MF.getSubtarget().getInstrInfo());
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
int Off = Offset; // ARM doesn't need the general 64-bit offsets
unsigned i = 0;
(void)Done;
}
-bool ARMBaseRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
+bool ARMBaseRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI, unsigned BaseReg,
int64_t Offset) const {
const MCInstrDesc &Desc = MI->getDesc();
unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
NumBits = 8;
break;
case ARMII::AddrModeT1_s:
- NumBits = 5;
+ NumBits = (BaseReg == ARM::SP ? 8 : 5);
Scale = 4;
isSigned = false;
break;
void
ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
- int SPAdj, RegScavenger *RS) const {
- unsigned i = 0;
+ int SPAdj, unsigned FIOperandNum,
+ RegScavenger *RS) const {
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
- const ARMFrameLowering *TFI =
- static_cast<const ARMFrameLowering*>(MF.getTarget().getFrameLowering());
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo *>(MF.getSubtarget().getInstrInfo());
+ const ARMFrameLowering *TFI = getFrameLowering(MF);
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
assert(!AFI->isThumb1OnlyFunction() &&
"This eliminateFrameIndex does not support Thumb1!");
-
- while (!MI.getOperand(i).isFI()) {
- ++i;
- assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
- }
-
- int FrameIndex = MI.getOperand(i).getIndex();
+ int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
unsigned FrameReg;
int Offset = TFI->ResolveFrameIndexReference(MF, FrameIndex, FrameReg, SPAdj);
// means the stack pointer cannot be used to access the emergency spill slot
// when !hasReservedCallFrame().
#ifndef NDEBUG
- if (RS && FrameReg == ARM::SP && FrameIndex == RS->getScavengingFrameIndex()){
+ if (RS && FrameReg == ARM::SP && RS->isScavengingFrameIndex(FrameIndex)){
assert(TFI->hasReservedCallFrame(MF) &&
"Cannot use SP to access the emergency spill slot in "
"functions without a reserved call frame");
}
#endif // NDEBUG
- // Special handling of dbg_value instructions.
- if (MI.isDebugValue()) {
- MI.getOperand(i). ChangeToRegister(FrameReg, false /*isDef*/);
- MI.getOperand(i+1).ChangeToImmediate(Offset);
- return;
- }
+ assert(!MI.isDebugValue() && "DBG_VALUEs should be handled in target-independent code");
// Modify MI as necessary to handle as much of 'Offset' as possible
bool Done = false;
if (!AFI->isThumbFunction())
- Done = rewriteARMFrameIndex(MI, i, FrameReg, Offset, TII);
+ Done = rewriteARMFrameIndex(MI, FIOperandNum, FrameReg, Offset, TII);
else {
assert(AFI->isThumb2Function());
- Done = rewriteT2FrameIndex(MI, i, FrameReg, Offset, TII);
+ Done = rewriteT2FrameIndex(MI, FIOperandNum, FrameReg, Offset, TII);
}
if (Done)
return;
unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
if (Offset == 0)
// Must be addrmode4/6.
- MI.getOperand(i).ChangeToRegister(FrameReg, false, false, false);
+ MI.getOperand(FIOperandNum).ChangeToRegister(FrameReg, false, false, false);
else {
ScratchReg = MF.getRegInfo().createVirtualRegister(&ARM::GPRRegClass);
if (!AFI->isThumbFunction())
Offset, Pred, PredReg, TII);
}
// Update the original instruction to use the scratch register.
- MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
+ MI.getOperand(FIOperandNum).ChangeToRegister(ScratchReg, false, false,true);
}
}
+
+bool ARMBaseRegisterInfo::shouldCoalesce(MachineInstr *MI,
+ const TargetRegisterClass *SrcRC,
+ unsigned SubReg,
+ const TargetRegisterClass *DstRC,
+ unsigned DstSubReg,
+ const TargetRegisterClass *NewRC) const {
+ auto MBB = MI->getParent();
+ auto MF = MBB->getParent();
+ const MachineRegisterInfo &MRI = MF->getRegInfo();
+ // If not copying into a sub-register this should be ok because we shouldn't
+ // need to split the reg.
+ if (!DstSubReg)
+ return true;
+ // Small registers don't frequently cause a problem, so we can coalesce them.
+ if (NewRC->getSize() < 32 && DstRC->getSize() < 32 && SrcRC->getSize() < 32)
+ return true;
+
+ auto NewRCWeight =
+ MRI.getTargetRegisterInfo()->getRegClassWeight(NewRC);
+ auto SrcRCWeight =
+ MRI.getTargetRegisterInfo()->getRegClassWeight(SrcRC);
+ auto DstRCWeight =
+ MRI.getTargetRegisterInfo()->getRegClassWeight(DstRC);
+ // If the source register class is more expensive than the destination, the
+ // coalescing is probably profitable.
+ if (SrcRCWeight.RegWeight > NewRCWeight.RegWeight)
+ return true;
+ if (DstRCWeight.RegWeight > NewRCWeight.RegWeight)
+ return true;
+
+ // If the register allocator isn't constrained, we can always allow coalescing
+ // unfortunately we don't know yet if we will be constrained.
+ // The goal of this heuristic is to restrict how many expensive registers
+ // we allow to coalesce in a given basic block.
+ auto AFI = MF->getInfo<ARMFunctionInfo>();
+ auto It = AFI->getCoalescedWeight(MBB);
+
+ DEBUG(dbgs() << "\tARM::shouldCoalesce - Coalesced Weight: "
+ << It->second << "\n");
+ DEBUG(dbgs() << "\tARM::shouldCoalesce - Reg Weight: "
+ << NewRCWeight.RegWeight << "\n");
+
+ // This number is the largest round number that which meets the criteria:
+ // (1) addresses PR18825
+ // (2) generates better code in some test cases (like vldm-shed-a9.ll)
+ // (3) Doesn't regress any test cases (in-tree, test-suite, and SPEC)
+ // In practice the SizeMultiplier will only factor in for straight line code
+ // that uses a lot of NEON vectors, which isn't terribly common.
+ unsigned SizeMultiplier = MBB->size()/100;
+ SizeMultiplier = SizeMultiplier ? SizeMultiplier : 1;
+ if (It->second < NewRCWeight.WeightLimit * SizeMultiplier) {
+ It->second += NewRCWeight.RegWeight;
+ return true;
+ }
+ return false;
+}
projects / oota-llvm.git / blobdiff