Rewrite stack callee saved spills and restores to use push/pop instructions.

Remove movePastCSLoadStoreOps and associated code for simple pointer
increments. Update routines that depended upon other opcodes for save/restore.

Adjust all testcases accordingly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119725 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Eric Christopher 2010-11-18 19:40:05 +00:00
parent 9fe010ecf8
commit 8b3ca6216d
7 changed files with 200 additions and 97 deletions

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@ -197,6 +197,48 @@ ARMBaseInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
return NewMIs[0];
}
void
ARMBaseInstrInfo::emitPushInst(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI, unsigned Opc,
bool(*Func)(unsigned, bool)) const {
MachineFunction &MF = *MBB.getParent();
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
MachineInstrBuilder MIB = BuildMI(MF, DL, get(Opc));
MIB.addReg(ARM::SP, getDefRegState(true));
MIB.addReg(ARM::SP);
AddDefaultPred(MIB);
bool NumRegs = false;
for (unsigned i = CSI.size(); i != 0; --i) {
unsigned Reg = CSI[i-1].getReg();
if (!(Func)(Reg, Subtarget.isTargetDarwin())) continue;
// Add the callee-saved register as live-in unless it's LR and
// @llvm.returnaddress is called. If LR is returned for @llvm.returnaddress
// then it's already added to the function and entry block live-in sets.
bool isKill = true;
if (Reg == ARM::LR) {
if (MF.getFrameInfo()->isReturnAddressTaken() &&
MF.getRegInfo().isLiveIn(Reg))
isKill = false;
}
if (isKill)
MBB.addLiveIn(Reg);
NumRegs = true;
MIB.addReg(Reg, getKillRegState(isKill));
}
// It's illegal to emit push instruction without operands.
if (NumRegs)
MBB.insert(MI, &*MIB);
else
MF.DeleteMachineInstr(MIB);
}
bool
ARMBaseInstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
@ -205,35 +247,79 @@ ARMBaseInstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
if (CSI.empty())
return false;
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
DebugLoc DL = MI->getDebugLoc();
unsigned PushOpc = AFI->isThumbFunction() ? ARM::t2STMDB_UPD : ARM::STMDB_UPD;
unsigned FltOpc = ARM::VSTMDDB_UPD;
emitPushInst(MBB, MI, CSI, PushOpc, &isARMArea1Register);
emitPushInst(MBB, MI, CSI, PushOpc, &isARMArea2Register);
emitPushInst(MBB, MI, CSI, FltOpc, &isARMArea3Register);
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
bool isKill = true;
// Add the callee-saved register as live-in unless it's LR and
// @llvm.returnaddress is called. If LR is returned for @llvm.returnaddress
// then it's already added to the function and entry block live-in sets.
if (Reg == ARM::LR) {
MachineFunction &MF = *MBB.getParent();
if (MF.getFrameInfo()->isReturnAddressTaken() &&
MF.getRegInfo().isLiveIn(Reg))
isKill = false;
}
if (isKill)
MBB.addLiveIn(Reg);
// Insert the spill to the stack frame. The register is killed at the spill
//
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
storeRegToStackSlot(MBB, MI, Reg, isKill,
CSI[i].getFrameIdx(), RC, TRI);
}
return true;
}
void
ARMBaseInstrInfo::emitPopInst(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI, unsigned Opc,
bool isVarArg, bool(*Func)(unsigned, bool)) const {
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
DebugLoc DL = MI->getDebugLoc();
MachineInstrBuilder MIB = BuildMI(MF, DL, get(Opc));
MIB.addReg(ARM::SP, getDefRegState(true));
MIB.addReg(ARM::SP);
AddDefaultPred(MIB);
bool NumRegs = false;
for (unsigned i = CSI.size(); i != 0; --i) {
unsigned Reg = CSI[i-1].getReg();
if (!(Func)(Reg, Subtarget.isTargetDarwin())) continue;
if (Reg == ARM::LR && !isVarArg) {
Reg = ARM::PC;
unsigned Opc = AFI->isThumbFunction() ? ARM::t2LDMIA_RET : ARM::LDMIA_RET;
(*MIB).setDesc(get(Opc));
MI = MBB.erase(MI);
}
MIB.addReg(Reg, RegState::Define);
NumRegs = true;
}
// It's illegal to emit pop instruction without operands.
if (NumRegs)
MBB.insert(MI, &*MIB);
else
MF.DeleteMachineInstr(MIB);
}
bool
ARMBaseInstrInfo::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty())
return false;
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
bool isVarArg = AFI->getVarArgsRegSaveSize() > 0;
DebugLoc DL = MI->getDebugLoc();
unsigned PopOpc = AFI->isThumbFunction() ? ARM::t2LDMIA_UPD : ARM::LDMIA_UPD;
unsigned FltOpc = ARM::VLDMDIA_UPD;
emitPopInst(MBB, MI, CSI, FltOpc, isVarArg, &isARMArea3Register);
emitPopInst(MBB, MI, CSI, PopOpc, isVarArg, &isARMArea2Register);
emitPopInst(MBB, MI, CSI, PopOpc, isVarArg, &isARMArea1Register);
return true;
}
// Branch analysis.
bool
ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
@ -2195,7 +2281,7 @@ int ARMBaseInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
case ARM::VSTMQIA:
case ARM::VSTMQDB:
return 2;
}
}
}
bool ARMBaseInstrInfo::

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@ -211,6 +211,21 @@ public:
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const;
bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const;
private:
void emitPopInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI, unsigned Opc,
bool isVarArg, bool(*Func)(unsigned, bool)) const;
void emitPushInst(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI, unsigned Opc,
bool(*Func)(unsigned, bool)) const;
public:
// Branch analysis.
virtual bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,

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@ -44,6 +44,45 @@ static inline bool isARMLowRegister(unsigned Reg) {
}
}
/// isARMArea1Register - Returns true if the register is a low register (r0-r7)
/// or a stack/pc register that we should push/pop.
static inline bool isARMArea1Register(unsigned Reg, bool isDarwin) {
using namespace ARM;
switch (Reg) {
case R0: case R1: case R2: case R3:
case R4: case R5: case R6: case R7:
case LR: case SP: case PC:
return true;
case R8: case R9: case R10: case R11:
// For darwin we want r7 and lr to be next to each other.
return !isDarwin;
default:
return false;
}
}
static inline bool isARMArea2Register(unsigned Reg, bool isDarwin) {
using namespace ARM;
switch (Reg) {
case R8: case R9: case R10: case R11:
// Darwin has this second area.
return isDarwin;
default:
return false;
}
}
static inline bool isARMArea3Register(unsigned Reg, bool isDarwin) {
using namespace ARM;
switch (Reg) {
case D15: case D14: case D13: case D12:
case D11: case D10: case D9: case D8:
return true;
default:
return false;
}
}
class ARMBaseRegisterInfo : public ARMGenRegisterInfo {
protected:
const ARMBaseInstrInfo &TII;

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@ -20,43 +20,6 @@
using namespace llvm;
/// 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).
static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
int Opc1, int Opc2, unsigned Area,
const ARMSubtarget &STI) {
while (MBBI != MBB.end() &&
((MBBI->getOpcode() == Opc1) || (MBBI->getOpcode() == Opc2)) &&
MBBI->getOperand(1).isFI()) {
if (Area != 0) {
bool Done = false;
unsigned Category = 0;
switch (MBBI->getOperand(0).getReg()) {
case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
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;
break;
default:
Done = true;
break;
}
if (Done || Category != Area)
break;
}
++MBBI;
}
}
static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
for (unsigned i = 0; CSRegs[i]; ++i)
if (Reg == CSRegs[i])
@ -67,11 +30,21 @@ static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
static bool isCSRestore(MachineInstr *MI,
const ARMBaseInstrInfo &TII,
const unsigned *CSRegs) {
return ((MI->getOpcode() == (int)ARM::VLDRD ||
MI->getOpcode() == (int)ARM::LDRi12 ||
MI->getOpcode() == (int)ARM::t2LDRi12) &&
MI->getOperand(1).isFI() &&
isCalleeSavedRegister(MI->getOperand(0).getReg(), 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) {
// 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)
if (!isCalleeSavedRegister(MI->getOperand(i).getReg(), CSRegs))
return false;
return true;
}
return false;
}
static void
@ -154,11 +127,10 @@ void ARMFrameInfo::emitPrologue(MachineFunction &MF) const {
DPRCSSize += 8;
}
}
// Build the new SUBri to adjust SP for integer callee-save spill area 1.
emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS1Size);
movePastCSLoadStoreOps(MBB, MBBI, ARM::STRi12, ARM::t2STRi12, 1, STI);
// Move past area 1.
if (GPRCS1Size > 0) MBBI++;
// 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
@ -172,14 +144,10 @@ void ARMFrameInfo::emitPrologue(MachineFunction &MF) const {
.addFrameIndex(FramePtrSpillFI).addImm(0);
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::STRi12, ARM::t2STRi12, 2, STI);
emitSPUpdate(isARM, MBB, MBBI, dl, TII, -DPRCSSize);
// Move past area 2.
if (GPRCS2Size > 0) MBBI++;
// Determine starting offsets of spill areas.
unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
@ -191,7 +159,9 @@ void ARMFrameInfo::emitPrologue(MachineFunction &MF) const {
AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
movePastCSLoadStoreOps(MBB, MBBI, ARM::VSTRD, 0, 3, STI);
// Move past area 3.
if (DPRCSSize > 0) MBBI++;
NumBytes = DPRCSOffset;
if (NumBytes) {
// Adjust SP after all the callee-save spills.
@ -325,17 +295,10 @@ void ARMFrameInfo::emitEpilogue(MachineFunction &MF,
} 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);
emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getDPRCalleeSavedAreaSize());
// Move SP to start of integer callee save spill area 1.
movePastCSLoadStoreOps(MBB, MBBI, ARM::LDRi12, 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::LDRi12, ARM::t2LDRi12, 1, STI);
emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea1Size());
// Increment past our save areas.
if (AFI->getDPRCalleeSavedAreaSize()) MBBI++;
if (AFI->getGPRCalleeSavedArea2Size()) MBBI++;
if (AFI->getGPRCalleeSavedArea1Size()) MBBI++;
}
if (RetOpcode == ARM::TCRETURNdi || RetOpcode == ARM::TCRETURNdiND ||

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@ -3,7 +3,7 @@
; LDM instruction, was causing an assertion failure because the microop count
; was being treated as an instruction count.
; CHECK: ldmia
; CHECK: push
; CHECK: ldmia
; CHECK: ldmia
; CHECK: ldmia

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@ -4,8 +4,8 @@
define i64 @t(i64 %a) nounwind readonly {
entry:
; CHECK: str lr, [sp, #-4]!
; CHECK: ldr lr, [sp], #4
; CHECK: push {lr}
; CHECK: ldmia sp!, {pc}
%0 = load i64** @b, align 4
%1 = load i64* %0, align 4
%2 = mul i64 %1, %a

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@ -39,7 +39,7 @@ entry:
; CHECK: ittt eq
; CHECK: moveq r0
; CHECK-NOT: LBB0_
; CHECK: ldreq
; CHECK: popeq
; CHECK: popeq
switch i32 undef, label %bb7 [
i32 37, label %bb43