? DarwinCalleeSavedRegClasses : CalleeSavedRegClasses;
}
-BitVector ARMBaseRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
+BitVector ARMBaseRegisterInfo::
+getReservedRegs(const MachineFunction &MF) const {
// FIXME: avoid re-calculating this everytime.
BitVector Reserved(getNumRegs());
Reserved.set(ARM::SP);
}
}
-static unsigned calculateMaxStackAlignment(const MachineFrameInfo *FFI) {
- unsigned MaxAlign = 0;
-
- for (int i = FFI->getObjectIndexBegin(),
- e = FFI->getObjectIndexEnd(); i != e; ++i) {
- if (FFI->isDeadObjectIndex(i))
- continue;
-
- unsigned Align = FFI->getObjectAlignment(i);
- MaxAlign = std::max(MaxAlign, Align);
- }
-
- return MaxAlign;
-}
-
/// hasFP - Return true if the specified function should have a dedicated frame
/// pointer register. This is true if the function has variable sized allocas
/// or if frame pointer elimination is disabled.
///
bool ARMBaseRegisterInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- return (NoFramePointerElim ||
+ return ((NoFramePointerElim && MFI->hasCalls())||
needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
MFI->isFrameAddressTaken());
}
+bool ARMBaseRegisterInfo::canRealignStack(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ return (RealignStack &&
+ !AFI->isThumb1OnlyFunction() &&
+ !MFI->hasVarSizedObjects());
+}
+
bool ARMBaseRegisterInfo::
needsStackRealignment(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
!MFI->hasVarSizedObjects());
}
-bool ARMBaseRegisterInfo::cannotEliminateFrame(const MachineFunction &MF) const {
+bool ARMBaseRegisterInfo::
+cannotEliminateFrame(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
if (NoFramePointerElim && MFI->hasCalls())
return true;
}
/// estimateStackSize - Estimate and return the size of the frame.
-static unsigned estimateStackSize(MachineFunction &MF, MachineFrameInfo *MFI) {
+static unsigned estimateStackSize(MachineFunction &MF) {
const MachineFrameInfo *FFI = MF.getFrameInfo();
int Offset = 0;
for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
/// estimateRSStackSizeLimit - Look at each instruction that references stack
/// frames and return the stack size limit beyond which some of these
-/// instructions will require scratch register during their expansion later.
+/// instructions will require a scratch register during their expansion later.
unsigned
ARMBaseRegisterInfo::estimateRSStackSizeLimit(MachineFunction &MF) const {
unsigned Limit = (1 << 12) - 1;
// When the stack offset is negative, we will end up using
// the i8 instructions instead.
return (1 << 8) - 1;
+
+ if (AddrMode == ARMII::AddrMode6)
+ return 0;
break; // At most one FI per instruction
}
}
void
ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS) const {
+ RegScavenger *RS) const {
// This tells PEI to spill the FP as if it is any other callee-save register
// to take advantage the eliminateFrameIndex machinery. This also ensures it
// is spilled in the order specified by getCalleeSavedRegs() to make it easier
SmallVector<unsigned, 4> UnspilledCS2GPRs;
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- MachineFrameInfo *MFI = MF.getFrameInfo();
-
- // Calculate and set max stack object alignment early, so we can decide
- // whether we will need stack realignment (and thus FP).
- if (RealignStack) {
- unsigned MaxAlign = std::max(MFI->getMaxAlignment(),
- calculateMaxStackAlignment(MFI));
- MFI->setMaxAlignment(MaxAlign);
- }
+ // Spill R4 if Thumb2 function requires stack realignment - it will be used as
+ // scratch register.
+ // FIXME: It will be better just to find spare register here.
+ if (needsStackRealignment(MF) &&
+ AFI->isThumb2Function())
+ MF.getRegInfo().setPhysRegUsed(ARM::R4);
// Don't spill FP if the frame can be eliminated. This is determined
// by scanning the callee-save registers to see if any is used.
}
}
+ // If any of the stack slot references may be out of range of an immediate
+ // offset, make sure a register (or a spill slot) is available for the
+ // register scavenger. Note that if we're indexing off the frame pointer, the
+ // effective stack size is 4 bytes larger since the FP points to the stack
+ // slot of the previous FP.
+ bool BigStack = RS &&
+ estimateStackSize(MF) + (hasFP(MF) ? 4 : 0) >= estimateRSStackSizeLimit(MF);
+
bool ExtraCSSpill = false;
- if (!CanEliminateFrame || cannotEliminateFrame(MF)) {
+ if (BigStack || !CanEliminateFrame || cannotEliminateFrame(MF)) {
AFI->setHasStackFrame(true);
// If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.
// callee-saved register or reserve a special spill slot to facilitate
// register scavenging. Thumb1 needs a spill slot for stack pointer
// adjustments also, even when the frame itself is small.
- if (RS && !ExtraCSSpill) {
- MachineFrameInfo *MFI = MF.getFrameInfo();
- // If any of the stack slot references may be out of range of an
- // immediate offset, make sure a register (or a spill slot) is
- // available for the register scavenger. Note that if we're indexing
- // off the frame pointer, the effective stack size is 4 bytes larger
- // since the FP points to the stack slot of the previous FP.
- if (estimateStackSize(MF, MFI) + (hasFP(MF) ? 4 : 0)
- >= estimateRSStackSizeLimit(MF)) {
- // If any non-reserved CS register isn't spilled, just spill one or two
- // extra. That should take care of it!
- unsigned NumExtras = TargetAlign / 4;
- SmallVector<unsigned, 2> Extras;
- while (NumExtras && !UnspilledCS1GPRs.empty()) {
- unsigned Reg = UnspilledCS1GPRs.back();
- UnspilledCS1GPRs.pop_back();
+ if (BigStack && !ExtraCSSpill) {
+ // If any non-reserved CS register isn't spilled, just spill one or two
+ // extra. That should take care of it!
+ unsigned NumExtras = TargetAlign / 4;
+ SmallVector<unsigned, 2> Extras;
+ while (NumExtras && !UnspilledCS1GPRs.empty()) {
+ unsigned Reg = UnspilledCS1GPRs.back();
+ UnspilledCS1GPRs.pop_back();
+ if (!isReservedReg(MF, Reg)) {
+ Extras.push_back(Reg);
+ NumExtras--;
+ }
+ }
+ // For non-Thumb1 functions, also check for hi-reg CS registers
+ if (!AFI->isThumb1OnlyFunction()) {
+ while (NumExtras && !UnspilledCS2GPRs.empty()) {
+ unsigned Reg = UnspilledCS2GPRs.back();
+ UnspilledCS2GPRs.pop_back();
if (!isReservedReg(MF, Reg)) {
Extras.push_back(Reg);
NumExtras--;
}
}
- // For non-Thumb1 functions, also check for hi-reg CS registers
- if (!AFI->isThumb1OnlyFunction()) {
- while (NumExtras && !UnspilledCS2GPRs.empty()) {
- unsigned Reg = UnspilledCS2GPRs.back();
- UnspilledCS2GPRs.pop_back();
- if (!isReservedReg(MF, Reg)) {
- Extras.push_back(Reg);
- NumExtras--;
- }
- }
- }
- if (Extras.size() && NumExtras == 0) {
- for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
- MF.getRegInfo().setPhysRegUsed(Extras[i]);
- AFI->setCSRegisterIsSpilled(Extras[i]);
- }
- } else if (!AFI->isThumb1OnlyFunction()) {
- // note: Thumb1 functions spill to R12, not the stack.
- // Reserve a slot closest to SP or frame pointer.
- const TargetRegisterClass *RC = ARM::GPRRegisterClass;
- RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
- RC->getAlignment(),
- false));
+ }
+ if (Extras.size() && NumExtras == 0) {
+ for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
+ MF.getRegInfo().setPhysRegUsed(Extras[i]);
+ AFI->setCSRegisterIsSpilled(Extras[i]);
}
+ } else if (!AFI->isThumb1OnlyFunction()) {
+ // note: Thumb1 functions spill to R12, not the stack. Reserve a slot
+ // closest to SP or frame pointer.
+ const TargetRegisterClass *RC = ARM::GPRRegisterClass;
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+ RC->getAlignment(),
+ false));
}
}
}
}
int
-ARMBaseRegisterInfo::getFrameIndexReference(MachineFunction &MF, int FI,
+ARMBaseRegisterInfo::getFrameIndexReference(const MachineFunction &MF, int FI,
unsigned &FrameReg) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+
const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
int Offset = MFI->getObjectOffset(FI) + MFI->getStackSize();
bool isFixed = MFI->isFixedObjectIndex(FI);
+ FrameReg = ARM::SP;
if (AFI->isGPRCalleeSavedArea1Frame(FI))
Offset -= AFI->getGPRCalleeSavedArea1Offset();
else if (AFI->isGPRCalleeSavedArea2Frame(FI))
int
-ARMBaseRegisterInfo::getFrameIndexOffset(MachineFunction &MF, int FI) const {
+ARMBaseRegisterInfo::getFrameIndexOffset(const MachineFunction &MF,
+ int FI) const {
unsigned FrameReg;
return getFrameIndexReference(MF, FI, FrameReg);
}
}
unsigned ARMBaseRegisterInfo::getRegisterPairEven(unsigned Reg,
- const MachineFunction &MF) const {
+ const MachineFunction &MF) const {
switch (Reg) {
default: break;
// Return 0 if either register of the pair is a special register.
return !MF.getFrameInfo()->hasVarSizedObjects();
}
+// canSimplifyCallFramePseudos - If there is a reserved call frame, the
+// call frame pseudos can be simplified. Unlike most targets, having a FP
+// is not sufficient here since we still may reference some objects via SP
+// even when FP is available in Thumb2 mode.
+bool ARMBaseRegisterInfo::
+canSimplifyCallFramePseudos(MachineFunction &MF) const {
+ return hasReservedCallFrame(MF) || MF.getFrameInfo()->hasVarSizedObjects();
+}
+
static void
emitSPUpdate(bool isARM,
MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
assert(!AFI->isThumb1OnlyFunction() &&
- "This eliminateCallFramePseudoInstr does not suppor Thumb1!");
+ "This eliminateCallFramePseudoInstr does not support Thumb1!");
bool isARM = !AFI->isThumbFunction();
// Replace the pseudo instruction with a new instruction...
unsigned Opc = Old->getOpcode();
- ARMCC::CondCodes Pred = (ARMCC::CondCodes)Old->getOperand(1).getImm();
- // FIXME: Thumb2 version of ADJCALLSTACKUP and ADJCALLSTACKDOWN?
+ 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();
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
- const MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
assert(!AFI->isThumb1OnlyFunction() &&
"This eliminateFrameIndex does not support Thumb1!");
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
- unsigned FrameReg = ARM::SP;
int FrameIndex = MI.getOperand(i).getIndex();
- int Offset = MFI->getObjectOffset(FrameIndex) + MFI->getStackSize() + SPAdj;
+ unsigned FrameReg;
- Offset = getFrameIndexReference(MF, FrameIndex, FrameReg);
+ int Offset = getFrameIndexReference(MF, FrameIndex, FrameReg);
if (FrameReg != ARM::SP)
SPAdj = 0;
+ Offset += SPAdj;
// Modify MI as necessary to handle as much of 'Offset' as possible
bool Done = false;
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
assert(!AFI->isThumb1OnlyFunction() &&
- "This emitPrologue does not suppor Thumb1!");
+ "This emitPrologue does not support Thumb1!");
bool isARM = !AFI->isThumbFunction();
unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
unsigned NumBytes = MFI->getStackSize();
// If we need dynamic stack realignment, do it here.
if (needsStackRealignment(MF)) {
- unsigned Opc;
unsigned MaxAlign = MFI->getMaxAlignment();
assert (!AFI->isThumb1OnlyFunction());
- Opc = AFI->isThumbFunction() ? ARM::t2BICri : ARM::BICri;
-
- AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(Opc), ARM::SP)
+ if (!AFI->isThumbFunction()) {
+ // Emit bic sp, sp, MaxAlign
+ AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
+ TII.get(ARM::BICri), ARM::SP)
.addReg(ARM::SP, RegState::Kill)
.addImm(MaxAlign-1)));
+ } else {
+ // We cannot use sp as source/dest register here, thus we're emitting the
+ // following sequence:
+ // mov r4, sp
+ // bic r4, r4, MaxAlign
+ // mov sp, r4
+ // FIXME: It will be better just to find spare register here.
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2tgpr), ARM::R4)
+ .addReg(ARM::SP, RegState::Kill);
+ AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
+ TII.get(ARM::t2BICri), ARM::R4)
+ .addReg(ARM::R4, RegState::Kill)
+ .addImm(MaxAlign-1)));
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVtgpr2gpr), ARM::SP)
+ .addReg(ARM::R4, RegState::Kill);
+ }
}
}
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
assert(!AFI->isThumb1OnlyFunction() &&
- "This emitEpilogue does not suppor Thumb1!");
+ "This emitEpilogue does not support Thumb1!");
bool isARM = !AFI->isThumbFunction();
unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
emitSPUpdate(isARM, MBB, MBBI, dl, TII, VARegSaveSize);
}
-namespace {
- struct MaximalStackAlignmentCalculator : public MachineFunctionPass {
- static char ID;
- MaximalStackAlignmentCalculator() : MachineFunctionPass(&ID) {}
-
- virtual bool runOnMachineFunction(MachineFunction &MF) {
- MachineFrameInfo *FFI = MF.getFrameInfo();
- MachineRegisterInfo &RI = MF.getRegInfo();
-
- // Calculate max stack alignment of all already allocated stack objects.
- unsigned MaxAlign = calculateMaxStackAlignment(FFI);
-
- // Be over-conservative: scan over all vreg defs and find, whether vector
- // registers are used. If yes - there is probability, that vector register
- // will be spilled and thus stack needs to be aligned properly.
- for (unsigned RegNum = TargetRegisterInfo::FirstVirtualRegister;
- RegNum < RI.getLastVirtReg(); ++RegNum)
- MaxAlign = std::max(MaxAlign, RI.getRegClass(RegNum)->getAlignment());
-
- if (FFI->getMaxAlignment() == MaxAlign)
- return false;
-
- FFI->setMaxAlignment(MaxAlign);
- return true;
- }
-
- virtual const char *getPassName() const {
- return "ARM Stack Required Alignment Auto-Detector";
- }
-
- virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.setPreservesCFG();
- MachineFunctionPass::getAnalysisUsage(AU);
- }
- };
-
- char MaximalStackAlignmentCalculator::ID = 0;
-}
-
-FunctionPass*
-llvm::createARMMaxStackAlignmentCalculatorPass() {
- return new MaximalStackAlignmentCalculator();
-}
-
#include "ARMGenRegisterInfo.inc"
projects / oota-llvm.git / blobdiff