Simplify ARM callee-saved register handling by removing the distinction

between the high and low registers for prologue/epilogue code. This was
a Darwin-only thing that wasn't providing a realistic benefit anymore.
Combining the save areas simplifies the compiler code and results in better
ARM/Thumb2 codegen.

For example, previously we would generate code like:
        push    {r4, r5, r6, r7, lr}
        add     r7, sp, #12
        stmdb   sp!, {r8, r10, r11}
With this change, we combine the register saves and generate:
        push    {r4, r5, r6, r7, r8, r10, r11, lr}
        add     r7, sp, #12

rdar://8445635



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114340 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jim Grosbach 2010-09-20 19:32:20 +00:00
parent 43779dcfef
commit 1dc335a79f
5 changed files with 66 additions and 175 deletions

View File

@ -77,8 +77,8 @@ ARMBaseRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
static const unsigned DarwinCalleeSavedRegs[] = {
// Darwin ABI deviates from ARM standard ABI. R9 is not a callee-saved
// register.
ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4,
ARM::R11, ARM::R10, ARM::R8,
ARM::LR, ARM::R11, ARM::R10, ARM::R8,
ARM::R7, ARM::R6, ARM::R5, ARM::R4,
ARM::D15, ARM::D14, ARM::D13, ARM::D12,
ARM::D11, ARM::D10, ARM::D9, ARM::D8,
@ -701,7 +701,6 @@ ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
bool LRSpilled = false;
unsigned NumGPRSpills = 0;
SmallVector<unsigned, 4> UnspilledCS1GPRs;
SmallVector<unsigned, 4> UnspilledCS2GPRs;
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
MachineFrameInfo *MFI = MF.getFrameInfo();
@ -768,23 +767,7 @@ ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
break;
}
} else {
if (!STI.isTargetDarwin()) {
UnspilledCS1GPRs.push_back(Reg);
continue;
}
switch (Reg) {
case ARM::R4:
case ARM::R5:
case ARM::R6:
case ARM::R7:
case ARM::LR:
UnspilledCS1GPRs.push_back(Reg);
break;
default:
UnspilledCS2GPRs.push_back(Reg);
break;
}
UnspilledCS1GPRs.push_back(Reg);
}
}
@ -860,13 +843,6 @@ ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
break;
}
}
} else if (!UnspilledCS2GPRs.empty() &&
!AFI->isThumb1OnlyFunction()) {
unsigned Reg = UnspilledCS2GPRs.front();
MF.getRegInfo().setPhysRegUsed(Reg);
AFI->setCSRegisterIsSpilled(Reg);
if (!isReservedReg(MF, Reg))
ExtraCSSpill = true;
}
}
@ -890,17 +866,6 @@ ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
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]);
@ -958,10 +923,8 @@ ARMBaseRegisterInfo::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();
if (AFI->isGPRCalleeSavedAreaFrame(FI))
return Offset - AFI->getGPRCalleeSavedAreaOffset();
else if (AFI->isDPRCalleeSavedAreaFrame(FI))
return Offset - AFI->getDPRCalleeSavedAreaOffset();
@ -1651,8 +1614,7 @@ ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
}
/// Move iterator past the next bunch of callee save load / store ops for
/// the particular spill area (1: integer area 1, 2: integer area 2,
/// 3: fp area, 0: don't care).
/// the particular spill area (1: integer area 1, 2: fp area, 0: don't care).
static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
int Opc1, int Opc2, unsigned Area,
@ -1665,15 +1627,13 @@ static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
unsigned Category = 0;
switch (MBBI->getOperand(0).getReg()) {
case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
case ARM::LR:
Category = 1;
break;
case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
Category = STI.isTargetDarwin() ? 2 : 1;
break;
case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
Category = 3;
Category = 2;
break;
default:
Done = true;
@ -1703,7 +1663,7 @@ emitPrologue(MachineFunction &MF) const {
// Determine the sizes of each callee-save spill areas and record which frame
// belongs to which callee-save spill areas.
unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
unsigned GPRCSSize = 0/*, GPRCS2Size = 0*/, DPRCSSize = 0;
int FramePtrSpillFI = 0;
// Allocate the vararg register save area. This is not counted in NumBytes.
@ -1724,25 +1684,15 @@ emitPrologue(MachineFunction &MF) const {
case ARM::R5:
case ARM::R6:
case ARM::R7:
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::LR:
if (Reg == FramePtr)
FramePtrSpillFI = FI;
if (STI.isTargetDarwin()) {
AFI->addGPRCalleeSavedArea2Frame(FI);
GPRCS2Size += 4;
} else {
AFI->addGPRCalleeSavedArea1Frame(FI);
GPRCS1Size += 4;
}
AFI->addGPRCalleeSavedAreaFrame(FI);
GPRCSSize += 4;
break;
default:
AFI->addDPRCalleeSavedAreaFrame(FI);
@ -1750,15 +1700,11 @@ emitPrologue(MachineFunction &MF) const {
}
}
// Build the new SUBri to adjust SP for integer callee-save spill area 1.
emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS1Size);
// Build the new SUBri to adjust SP for integer callee-save spill area.
emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCSSize);
movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 1, STI);
// Set FP to point to the stack slot that contains the previous FP.
// For Darwin, FP is R7, which has now been stored in spill area 1.
// Otherwise, if this is not Darwin, 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;
@ -1768,25 +1714,19 @@ emitPrologue(MachineFunction &MF) const {
AddDefaultCC(AddDefaultPred(MIB));
}
// Build the new SUBri to adjust SP for integer callee-save spill area 2.
emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS2Size);
// Build the new SUBri to adjust SP for FP callee-save spill area.
movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 2, STI);
emitSPUpdate(isARM, MBB, MBBI, dl, TII, -DPRCSSize);
// Determine starting offsets of spill areas.
unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
unsigned DPRCSOffset = NumBytes - (GPRCSSize + DPRCSSize);
unsigned GPRCSOffset = DPRCSOffset + DPRCSSize;
if (HasFP)
AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
NumBytes);
AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
AFI->setGPRCalleeSavedAreaOffset(GPRCSOffset);
AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
movePastCSLoadStoreOps(MBB, MBBI, ARM::VSTRD, 0, 3, STI);
movePastCSLoadStoreOps(MBB, MBBI, ARM::VSTRD, 0, 2, STI);
NumBytes = DPRCSOffset;
if (NumBytes) {
// Adjust SP after all the callee-save spills.
@ -1801,8 +1741,7 @@ emitPrologue(MachineFunction &MF) const {
AFI->setShouldRestoreSPFromFP(true);
}
AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
AFI->setGPRCalleeSavedAreaSize(GPRCSSize);
AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
// If we need dynamic stack realignment, do it here. Be paranoid and make
@ -1904,8 +1843,7 @@ emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const {
}
// Move SP to start of FP callee save spill area.
NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
AFI->getGPRCalleeSavedArea2Size() +
NumBytes -= (AFI->getGPRCalleeSavedAreaSize() +
AFI->getDPRCalleeSavedAreaSize());
// Reset SP based on frame pointer only if the stack frame extends beyond
@ -1931,17 +1869,13 @@ emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const {
} else if (NumBytes)
emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
// Move SP to start of integer callee save spill area 2.
movePastCSLoadStoreOps(MBB, MBBI, ARM::VLDRD, 0, 3, STI);
// Move SP to start of integer callee save spill area.
movePastCSLoadStoreOps(MBB, MBBI, ARM::VLDRD, 0, 2, STI);
emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getDPRCalleeSavedAreaSize());
// Move SP to start of integer callee save spill area 1.
movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 2, STI);
emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea2Size());
// Move SP to SP upon entry to the function.
movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 1, STI);
emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea1Size());
emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedAreaSize());
}
if (RetOpcode == ARM::TCRETURNdi || RetOpcode == ARM::TCRETURNdiND ||

View File

@ -55,28 +55,23 @@ class ARMFunctionInfo : public MachineFunctionInfo {
/// spill stack offset.
unsigned FramePtrSpillOffset;
/// GPRCS1Offset, GPRCS2Offset, DPRCSOffset - Starting offset of callee saved
/// register spills areas. For Mac OS X:
/// GPRCSOffset, GPRCS2Offset, DPRCSOffset - Starting offset of callee saved
/// register spills areas (excluding R9 for Mac OS X):
///
/// GPR callee-saved (1) : r4, r5, r6, r7, lr
/// --------------------------------------------
/// GPR callee-saved (2) : r8, r10, r11
/// GPR callee-saved (1) : r4, r5, r6, r7, r8, r9, r10, r11, lr
/// --------------------------------------------
/// DPR callee-saved : d8 - d15
unsigned GPRCS1Offset;
unsigned GPRCS2Offset;
unsigned GPRCSOffset;
unsigned DPRCSOffset;
/// GPRCS1Size, GPRCS2Size, DPRCSSize - Sizes of callee saved register spills
/// GPRCSSize, GPRCS2Size, DPRCSSize - Sizes of callee saved register spills
/// areas.
unsigned GPRCS1Size;
unsigned GPRCS2Size;
unsigned GPRCSSize;
unsigned DPRCSSize;
/// GPRCS1Frames, GPRCS2Frames, DPRCSFrames - Keeps track of frame indices
/// GPRCSFrames, GPRCS2Frames, DPRCSFrames - Keeps track of frame indices
/// which belong to these spill areas.
BitVector GPRCS1Frames;
BitVector GPRCS2Frames;
BitVector GPRCSFrames;
BitVector DPRCSFrames;
/// SpilledCSRegs - A BitVector mask of all spilled callee-saved registers.
@ -101,9 +96,9 @@ public:
hasThumb2(false),
VarArgsRegSaveSize(0), HasStackFrame(false), RestoreSPFromFP(false),
LRSpilledForFarJump(false),
FramePtrSpillOffset(0), GPRCS1Offset(0), GPRCS2Offset(0), DPRCSOffset(0),
GPRCS1Size(0), GPRCS2Size(0), DPRCSSize(0),
GPRCS1Frames(0), GPRCS2Frames(0), DPRCSFrames(0),
FramePtrSpillOffset(0), GPRCSOffset(0), DPRCSOffset(0),
GPRCSSize(0), DPRCSSize(0),
GPRCSFrames(0), DPRCSFrames(0),
JumpTableUId(0), ConstPoolEntryUId(0), VarArgsFrameIndex(0),
HasITBlocks(false) {}
@ -112,9 +107,9 @@ public:
hasThumb2(MF.getTarget().getSubtarget<ARMSubtarget>().hasThumb2()),
VarArgsRegSaveSize(0), HasStackFrame(false), RestoreSPFromFP(false),
LRSpilledForFarJump(false),
FramePtrSpillOffset(0), GPRCS1Offset(0), GPRCS2Offset(0), DPRCSOffset(0),
GPRCS1Size(0), GPRCS2Size(0), DPRCSSize(0),
GPRCS1Frames(32), GPRCS2Frames(32), DPRCSFrames(32),
FramePtrSpillOffset(0), GPRCSOffset(0), DPRCSOffset(0),
GPRCSSize(0), DPRCSSize(0),
GPRCSFrames(32), DPRCSFrames(32),
SpilledCSRegs(MF.getTarget().getRegisterInfo()->getNumRegs()),
JumpTableUId(0), ConstPoolEntryUId(0), VarArgsFrameIndex(0),
HasITBlocks(false) {}
@ -138,31 +133,22 @@ public:
unsigned getFramePtrSpillOffset() const { return FramePtrSpillOffset; }
void setFramePtrSpillOffset(unsigned o) { FramePtrSpillOffset = o; }
unsigned getGPRCalleeSavedArea1Offset() const { return GPRCS1Offset; }
unsigned getGPRCalleeSavedArea2Offset() const { return GPRCS2Offset; }
unsigned getGPRCalleeSavedAreaOffset() const { return GPRCSOffset; }
unsigned getDPRCalleeSavedAreaOffset() const { return DPRCSOffset; }
void setGPRCalleeSavedArea1Offset(unsigned o) { GPRCS1Offset = o; }
void setGPRCalleeSavedArea2Offset(unsigned o) { GPRCS2Offset = o; }
void setGPRCalleeSavedAreaOffset(unsigned o) { GPRCSOffset = o; }
void setDPRCalleeSavedAreaOffset(unsigned o) { DPRCSOffset = o; }
unsigned getGPRCalleeSavedArea1Size() const { return GPRCS1Size; }
unsigned getGPRCalleeSavedArea2Size() const { return GPRCS2Size; }
unsigned getGPRCalleeSavedAreaSize() const { return GPRCSSize; }
unsigned getDPRCalleeSavedAreaSize() const { return DPRCSSize; }
void setGPRCalleeSavedArea1Size(unsigned s) { GPRCS1Size = s; }
void setGPRCalleeSavedArea2Size(unsigned s) { GPRCS2Size = s; }
void setGPRCalleeSavedAreaSize(unsigned s) { GPRCSSize = s; }
void setDPRCalleeSavedAreaSize(unsigned s) { DPRCSSize = s; }
bool isGPRCalleeSavedArea1Frame(int fi) const {
if (fi < 0 || fi >= (int)GPRCS1Frames.size())
bool isGPRCalleeSavedAreaFrame(int fi) const {
if (fi < 0 || fi >= (int)GPRCSFrames.size())
return false;
return GPRCS1Frames[fi];
}
bool isGPRCalleeSavedArea2Frame(int fi) const {
if (fi < 0 || fi >= (int)GPRCS2Frames.size())
return false;
return GPRCS2Frames[fi];
return GPRCSFrames[fi];
}
bool isDPRCalleeSavedAreaFrame(int fi) const {
if (fi < 0 || fi >= (int)DPRCSFrames.size())
@ -170,28 +156,16 @@ public:
return DPRCSFrames[fi];
}
void addGPRCalleeSavedArea1Frame(int fi) {
void addGPRCalleeSavedAreaFrame(int fi) {
if (fi >= 0) {
int Size = GPRCS1Frames.size();
int Size = GPRCSFrames.size();
if (fi >= Size) {
Size *= 2;
if (fi >= Size)
Size = fi+1;
GPRCS1Frames.resize(Size);
GPRCSFrames.resize(Size);
}
GPRCS1Frames[fi] = true;
}
}
void addGPRCalleeSavedArea2Frame(int fi) {
if (fi >= 0) {
int Size = GPRCS2Frames.size();
if (fi >= Size) {
Size *= 2;
if (fi >= Size)
Size = fi+1;
GPRCS2Frames.resize(Size);
}
GPRCS2Frames[fi] = true;
GPRCSFrames[fi] = true;
}
}
void addDPRCalleeSavedAreaFrame(int fi) {

View File

@ -597,10 +597,8 @@ Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
MF.getFrameInfo()->getStackSize() + SPAdj;
if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea1Offset();
else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea2Offset();
if (AFI->isGPRCalleeSavedAreaFrame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedAreaOffset();
else if (MF.getFrameInfo()->hasVarSizedObjects()) {
assert(SPAdj == 0 && hasFP(MF) && "Unexpected");
// There are alloca()'s in this function, must reference off the frame
@ -709,7 +707,7 @@ void Thumb1RegisterInfo::emitPrologue(MachineFunction &MF) const {
// Determine the sizes of each callee-save spill areas and record which frame
// belongs to which callee-save spill areas.
unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
unsigned GPRCSSize = 0, DPRCSSize = 0;
int FramePtrSpillFI = 0;
if (VARegSaveSize)
@ -729,25 +727,15 @@ void Thumb1RegisterInfo::emitPrologue(MachineFunction &MF) const {
case ARM::R5:
case ARM::R6:
case ARM::R7:
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::LR:
if (Reg == FramePtr)
FramePtrSpillFI = FI;
if (STI.isTargetDarwin()) {
AFI->addGPRCalleeSavedArea2Frame(FI);
GPRCS2Size += 4;
} else {
AFI->addGPRCalleeSavedArea1Frame(FI);
GPRCS1Size += 4;
}
AFI->addGPRCalleeSavedAreaFrame(FI);
GPRCSSize += 4;
break;
default:
AFI->addDPRCalleeSavedAreaFrame(FI);
@ -769,12 +757,10 @@ void Thumb1RegisterInfo::emitPrologue(MachineFunction &MF) const {
}
// Determine starting offsets of spill areas.
unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
unsigned DPRCSOffset = NumBytes - (GPRCSSize + DPRCSSize);
unsigned GPRCSOffset = DPRCSOffset + DPRCSSize;
AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
AFI->setGPRCalleeSavedAreaOffset(GPRCSOffset);
AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
NumBytes = DPRCSOffset;
@ -787,8 +773,7 @@ void Thumb1RegisterInfo::emitPrologue(MachineFunction &MF) const {
MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
AFI->getFramePtrSpillOffset());
AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
AFI->setGPRCalleeSavedAreaSize(GPRCSSize);
AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
// If we need a base pointer, set it up here. It's whatever the value
@ -849,8 +834,7 @@ void Thumb1RegisterInfo::emitEpilogue(MachineFunction &MF,
}
// Move SP to start of FP callee save spill area.
NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
AFI->getGPRCalleeSavedArea2Size() +
NumBytes -= (AFI->getGPRCalleeSavedAreaSize() +
AFI->getDPRCalleeSavedAreaSize());
if (AFI->shouldRestoreSPFromFP()) {

View File

@ -1,4 +1,4 @@
; RUN: llc < %s -stats |& grep {38.*Number of machine instrs printed}
; RUN: llc < %s -stats |& grep {36.*Number of machine instrs printed}
; RUN: llc < %s -stats |& not grep {.*Number of re-materialization}
; This test really wants to check that the resultant "cond_true" block only
; has a single store in it, and that cond_true55 only has code to materialize

View File

@ -32,15 +32,14 @@
define fastcc i32 @parse_percent_token() nounwind {
entry:
; CHECK: ittt eq
; CHECK: ittt eq
; CHECK: ittt eq
; CHECK: ittt eq
; CHECK: ittt eq
; CHECK: itt eq
; CHECK: itt eq
; CHECK: itt eq
; CHECK: itt eq
; CHECK: itt eq
; CHECK: moveq r0
; CHECK-NOT: LBB0_
; CHECK: ldreq
; CHECK: popeq
; CHECK: ldmiaeq
switch i32 undef, label %bb7 [
i32 37, label %bb43
i32 48, label %bb5