#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 ARMSubtarget &sti)
- : ARMGenRegisterInfo(ARM::LR, 0, 0, ARM::PC), STI(sti),
- FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11),
- BasePtr(ARM::R6) {
-}
-
-const uint16_t*
+ : ARMGenRegisterInfo(ARM::LR, 0, 0, ARM::PC), STI(sti), BasePtr(ARM::R6) {
+ if (STI.isTargetMachO()) {
+ if (STI.isTargetDarwin() || STI.isThumb1Only())
+ FramePtr = ARM::R7;
+ else
+ FramePtr = ARM::R11;
+ } else if (STI.isTargetWindows())
+ FramePtr = ARM::R11;
+ else // ARM EABI
+ FramePtr = STI.isThumb() ? ARM::R7 : ARM::R11;
+}
+
+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);
+ const MCPhysReg *RegList =
+ STI.isTargetDarwin() ? CSR_iOS_SaveList : CSR_AAPCS_SaveList;
+
+ if (!MF) return RegList;
+
+ 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;
+ }
}
-
- if (ghcCall)
- return CSR_GHC_SaveList;
- else
- return (STI.isTargetIOS() && !STI.isAAPCS_ABI())
- ? CSR_iOS_SaveList : CSR_AAPCS_SaveList;
-}
-const uint32_t*
-ARMBaseRegisterInfo::getCallPreservedMask(CallingConv::ID) const {
- return (STI.isTargetIOS() && !STI.isAAPCS_ABI())
- ? CSR_iOS_RegMask : CSR_AAPCS_RegMask;
+ return RegList;
}
const uint32_t*
-ARMBaseRegisterInfo::getThisReturnPreservedMask(CallingConv::ID) const {
- return (STI.isTargetIOS() && !STI.isAAPCS_ABI())
- ? CSR_iOS_ThisReturn_RegMask : CSR_AAPCS_ThisReturn_RegMask;
+ARMBaseRegisterInfo::getCallPreservedMask(CallingConv::ID CC) const {
+ 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(CallingConv::ID CC) const {
+ // 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 TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
// FIXME: avoid re-calculating this every time.
BitVector Reserved(getNumRegs());
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 TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
switch (RC->getID()) {
default:
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 TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
// 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
// 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 (MF.getFunction()->hasFnAttribute("no-realign-stack"))
return false;
if (AFI->isThumb1OnlyFunction())
return false;
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 (MF.getTarget()
+ .getSubtargetImpl()
+ ->getFrameLowering()
+ ->hasReservedCallFrame(MF))
return true;
// A base pointer is required and allowed. Check that it isn't too late to
// reserve it.
needsStackRealignment(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const Function *F = MF.getFunction();
- unsigned StackAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
+ unsigned StackAlign = MF.getTarget()
+ .getSubtargetImpl()
+ ->getFrameLowering()
+ ->getStackAlignment();
bool requiresRealignment =
((MFI->getMaxAlignment() > StackAlign) ||
F->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
unsigned
ARMBaseRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
- const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
+ const TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
if (TFI->hasFP(MF))
return FramePtr;
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.getTarget().getInstrInfo();
+ const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
MachineConstantPool *ConstantPool = MF.getConstantPool();
const Constant *C =
ConstantInt::get(Type::getInt32Ty(MF.getFunction()->getContext()), Val);
// 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 TargetFrameLowering *TFI = MF.getSubtarget().getFrameLowering();
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
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"
const MachineFunction &MF = *MBB->getParent();
MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+ 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.getTarget().getInstrInfo());
+ *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;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const ARMBaseInstrInfo &TII =
- *static_cast<const ARMBaseInstrInfo*>(MF.getTarget().getInstrInfo());
- const ARMFrameLowering *TFI =
- static_cast<const ARMFrameLowering*>(MF.getTarget().getFrameLowering());
+ *static_cast<const ARMBaseInstrInfo *>(MF.getSubtarget().getInstrInfo());
+ const ARMFrameLowering *TFI = static_cast<const ARMFrameLowering *>(
+ MF.getSubtarget().getFrameLowering());
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
assert(!AFI->isThumb1OnlyFunction() &&
"This eliminateFrameIndex does not support Thumb1!");
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;
+}
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