aboutsummaryrefslogtreecommitdiffstats
path: root/lib/Target/ARM/ARMFrameLowering.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'lib/Target/ARM/ARMFrameLowering.cpp')
-rw-r--r--lib/Target/ARM/ARMFrameLowering.cpp150
1 files changed, 82 insertions, 68 deletions
diff --git a/lib/Target/ARM/ARMFrameLowering.cpp b/lib/Target/ARM/ARMFrameLowering.cpp
index c8637be..d32bdbc 100644
--- a/lib/Target/ARM/ARMFrameLowering.cpp
+++ b/lib/Target/ARM/ARMFrameLowering.cpp
@@ -82,22 +82,11 @@ ARMFrameLowering::canSimplifyCallFramePseudos(const MachineFunction &MF) const {
return hasReservedCallFrame(MF) || MF.getFrameInfo()->hasVarSizedObjects();
}
-static bool isCalleeSavedRegister(unsigned Reg, const uint16_t *CSRegs) {
- for (unsigned i = 0; CSRegs[i]; ++i)
- if (Reg == CSRegs[i])
- return true;
- return false;
-}
-
static bool isCSRestore(MachineInstr *MI,
const ARMBaseInstrInfo &TII,
const uint16_t *CSRegs) {
// Integer spill area is handled with "pop".
- if (MI->getOpcode() == ARM::LDMIA_RET ||
- MI->getOpcode() == ARM::t2LDMIA_RET ||
- MI->getOpcode() == ARM::LDMIA_UPD ||
- MI->getOpcode() == ARM::t2LDMIA_UPD ||
- MI->getOpcode() == ARM::VLDMDIA_UPD) {
+ if (isPopOpcode(MI->getOpcode())) {
// The first two operands are predicates. The last two are
// imp-def and imp-use of SP. Check everything in between.
for (int i = 5, e = MI->getNumOperands(); i != e; ++i)
@@ -115,20 +104,31 @@ static bool isCSRestore(MachineInstr *MI,
return false;
}
-static void
-emitSPUpdate(bool isARM,
- MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
- DebugLoc dl, const ARMBaseInstrInfo &TII,
- int NumBytes, unsigned MIFlags = MachineInstr::NoFlags,
- ARMCC::CondCodes Pred = ARMCC::AL, unsigned PredReg = 0) {
+static void emitRegPlusImmediate(bool isARM, MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MBBI, DebugLoc dl,
+ const ARMBaseInstrInfo &TII, unsigned DestReg,
+ unsigned SrcReg, int NumBytes,
+ unsigned MIFlags = MachineInstr::NoFlags,
+ ARMCC::CondCodes Pred = ARMCC::AL,
+ unsigned PredReg = 0) {
if (isARM)
- emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
+ emitARMRegPlusImmediate(MBB, MBBI, dl, DestReg, SrcReg, NumBytes,
Pred, PredReg, TII, MIFlags);
else
- emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
+ emitT2RegPlusImmediate(MBB, MBBI, dl, DestReg, SrcReg, NumBytes,
Pred, PredReg, TII, MIFlags);
}
+static void emitSPUpdate(bool isARM, MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MBBI, DebugLoc dl,
+ const ARMBaseInstrInfo &TII, int NumBytes,
+ unsigned MIFlags = MachineInstr::NoFlags,
+ ARMCC::CondCodes Pred = ARMCC::AL,
+ unsigned PredReg = 0) {
+ emitRegPlusImmediate(isARM, MBB, MBBI, dl, TII, ARM::SP, ARM::SP, NumBytes,
+ MIFlags, Pred, PredReg);
+}
+
void ARMFrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineBasicBlock::iterator MBBI = MBB.begin();
@@ -175,6 +175,10 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF) const {
unsigned Reg = CSI[i].getReg();
int FI = CSI[i].getFrameIdx();
switch (Reg) {
+ case ARM::R0:
+ case ARM::R1:
+ case ARM::R2:
+ case ARM::R3:
case ARM::R4:
case ARM::R5:
case ARM::R6:
@@ -182,73 +186,61 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF) const {
case ARM::LR:
if (Reg == FramePtr)
FramePtrSpillFI = FI;
- AFI->addGPRCalleeSavedArea1Frame(FI);
GPRCS1Size += 4;
break;
case ARM::R8:
case ARM::R9:
case ARM::R10:
case ARM::R11:
+ case ARM::R12:
if (Reg == FramePtr)
FramePtrSpillFI = FI;
- if (STI.isTargetIOS()) {
- AFI->addGPRCalleeSavedArea2Frame(FI);
+ if (STI.isTargetIOS())
GPRCS2Size += 4;
- } else {
- AFI->addGPRCalleeSavedArea1Frame(FI);
+ else
GPRCS1Size += 4;
- }
break;
default:
// This is a DPR. Exclude the aligned DPRCS2 spills.
if (Reg == ARM::D8)
D8SpillFI = FI;
- if (Reg < ARM::D8 || Reg >= ARM::D8 + AFI->getNumAlignedDPRCS2Regs()) {
- AFI->addDPRCalleeSavedAreaFrame(FI);
+ if (Reg < ARM::D8 || Reg >= ARM::D8 + AFI->getNumAlignedDPRCS2Regs())
DPRCSSize += 8;
- }
}
}
// Move past area 1.
- if (GPRCS1Size > 0) MBBI++;
-
- // Set FP to point to the stack slot that contains the previous FP.
- // For iOS, FP is R7, which has now been stored in spill area 1.
- // Otherwise, if this is not iOS, all the callee-saved registers go
- // into spill area 1, including the FP in R11. In either case, it is
- // now safe to emit this assignment.
- bool HasFP = hasFP(MF);
- if (HasFP) {
- unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri : ARM::t2ADDri;
- MachineInstrBuilder MIB =
- BuildMI(MBB, MBBI, dl, TII.get(ADDriOpc), FramePtr)
- .addFrameIndex(FramePtrSpillFI).addImm(0)
- .setMIFlag(MachineInstr::FrameSetup);
- AddDefaultCC(AddDefaultPred(MIB));
- }
-
- // Move past area 2.
- if (GPRCS2Size > 0) MBBI++;
+ MachineBasicBlock::iterator LastPush = MBB.end(), FramePtrPush;
+ if (GPRCS1Size > 0)
+ FramePtrPush = LastPush = MBBI++;
// Determine starting offsets of spill areas.
+ bool HasFP = hasFP(MF);
unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
- if (HasFP)
+ int FramePtrOffsetInPush = 0;
+ if (HasFP) {
+ FramePtrOffsetInPush = MFI->getObjectOffset(FramePtrSpillFI) + GPRCS1Size;
AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
NumBytes);
+ }
AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
+ // Move past area 2.
+ if (GPRCS2Size > 0) {
+ LastPush = MBBI++;
+ }
+
// Move past area 3.
if (DPRCSSize > 0) {
- MBBI++;
+ LastPush = MBBI++;
// Since vpush register list cannot have gaps, there may be multiple vpush
// instructions in the prologue.
while (MBBI->getOpcode() == ARM::VSTMDDB_UPD)
- MBBI++;
+ LastPush = MBBI++;
}
// Move past the aligned DPRCS2 area.
@@ -264,8 +256,13 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF) const {
if (NumBytes) {
// Adjust SP after all the callee-save spills.
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes,
- MachineInstr::FrameSetup);
+ if (tryFoldSPUpdateIntoPushPop(MF, LastPush, NumBytes)) {
+ if (LastPush == FramePtrPush)
+ FramePtrOffsetInPush += NumBytes;
+ } else
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes,
+ MachineInstr::FrameSetup);
+
if (HasFP && isARM)
// Restore from fp only in ARM mode: e.g. sub sp, r7, #24
// Note it's not safe to do this in Thumb2 mode because it would have
@@ -278,6 +275,18 @@ void ARMFrameLowering::emitPrologue(MachineFunction &MF) const {
AFI->setShouldRestoreSPFromFP(true);
}
+ // Set FP to point to the stack slot that contains the previous FP.
+ // For iOS, FP is R7, which has now been stored in spill area 1.
+ // Otherwise, if this is not iOS, all the callee-saved registers go
+ // into spill area 1, including the FP in R11. In either case, it
+ // is in area one and the adjustment needs to take place just after
+ // that push.
+ if (HasFP)
+ emitRegPlusImmediate(!AFI->isThumbFunction(), MBB, ++FramePtrPush, dl, TII,
+ FramePtr, ARM::SP, FramePtrOffsetInPush,
+ MachineInstr::FrameSetup);
+
+
if (STI.isTargetELF() && hasFP(MF))
MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
AFI->getFramePtrSpillOffset());
@@ -373,11 +382,11 @@ void ARMFrameLowering::emitEpilogue(MachineFunction &MF,
emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
} else {
// Unwind MBBI to point to first LDR / VLDRD.
- const uint16_t *CSRegs = RegInfo->getCalleeSavedRegs();
+ const uint16_t *CSRegs = RegInfo->getCalleeSavedRegs(&MF);
if (MBBI != MBB.begin()) {
- do
+ do {
--MBBI;
- while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs));
+ } while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs));
if (!isCSRestore(MBBI, TII, CSRegs))
++MBBI;
}
@@ -421,8 +430,8 @@ void ARMFrameLowering::emitEpilogue(MachineFunction &MF,
ARM::SP)
.addReg(FramePtr));
}
- } else if (NumBytes)
- emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
+ } else if (NumBytes && !tryFoldSPUpdateIntoPushPop(MF, MBBI, NumBytes))
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
// Increment past our save areas.
if (AFI->getDPRCalleeSavedAreaSize()) {
@@ -501,12 +510,6 @@ ARMFrameLowering::ResolveFrameIndexReference(const MachineFunction &MF,
FrameReg = ARM::SP;
Offset += SPAdj;
- if (AFI->isGPRCalleeSavedArea1Frame(FI))
- return Offset - AFI->getGPRCalleeSavedArea1Offset();
- else if (AFI->isGPRCalleeSavedArea2Frame(FI))
- return Offset - AFI->getGPRCalleeSavedArea2Offset();
- else if (AFI->isDPRCalleeSavedAreaFrame(FI))
- return Offset - AFI->getDPRCalleeSavedAreaOffset();
// SP can move around if there are allocas. We may also lose track of SP
// when emergency spilling inside a non-reserved call frame setup.
@@ -658,6 +661,8 @@ void ARMFrameLowering::emitPopInst(MachineBasicBlock &MBB,
unsigned RetOpcode = MI->getOpcode();
bool isTailCall = (RetOpcode == ARM::TCRETURNdi ||
RetOpcode == ARM::TCRETURNri);
+ bool isInterrupt =
+ RetOpcode == ARM::SUBS_PC_LR || RetOpcode == ARM::t2SUBS_PC_LR;
SmallVector<unsigned, 4> Regs;
unsigned i = CSI.size();
@@ -672,7 +677,8 @@ void ARMFrameLowering::emitPopInst(MachineBasicBlock &MBB,
if (Reg >= ARM::D8 && Reg < ARM::D8 + NumAlignedDPRCS2Regs)
continue;
- if (Reg == ARM::LR && !isTailCall && !isVarArg && STI.hasV5TOps()) {
+ if (Reg == ARM::LR && !isTailCall && !isVarArg && !isInterrupt &&
+ STI.hasV5TOps()) {
Reg = ARM::PC;
LdmOpc = AFI->isThumbFunction() ? ARM::t2LDMIA_RET : ARM::LDMIA_RET;
// Fold the return instruction into the LDM.
@@ -1199,7 +1205,7 @@ ARMFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
// 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.
- const uint16_t *CSRegs = RegInfo->getCalleeSavedRegs();
+ const uint16_t *CSRegs = RegInfo->getCalleeSavedRegs(&MF);
for (unsigned i = 0; CSRegs[i]; ++i) {
unsigned Reg = CSRegs[i];
bool Spilled = false;
@@ -1226,6 +1232,8 @@ ARMFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
case ARM::LR:
LRSpilled = true;
// Fallthrough
+ case ARM::R0: case ARM::R1:
+ case ARM::R2: case ARM::R3:
case ARM::R4: case ARM::R5:
case ARM::R6: case ARM::R7:
CS1Spilled = true;
@@ -1240,6 +1248,8 @@ ARMFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
}
switch (Reg) {
+ case ARM::R0: case ARM::R1:
+ case ARM::R2: case ARM::R3:
case ARM::R4: case ARM::R5:
case ARM::R6: case ARM::R7:
case ARM::LR:
@@ -1295,8 +1305,12 @@ ARMFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
if (!LRSpilled && CS1Spilled) {
MRI.setPhysRegUsed(ARM::LR);
NumGPRSpills++;
- UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(),
- UnspilledCS1GPRs.end(), (unsigned)ARM::LR));
+ SmallVectorImpl<unsigned>::iterator LRPos;
+ LRPos = std::find(UnspilledCS1GPRs.begin(), UnspilledCS1GPRs.end(),
+ (unsigned)ARM::LR);
+ if (LRPos != UnspilledCS1GPRs.end())
+ UnspilledCS1GPRs.erase(LRPos);
+
ForceLRSpill = false;
ExtraCSSpill = true;
}
generated by cgit v1.1 at 2024-05-17 20:42:35 +0000