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Diffstat (limited to 'lib/Target/ARM/Thumb1FrameLowering.cpp')
-rw-r--r--lib/Target/ARM/Thumb1FrameLowering.cpp110
1 files changed, 78 insertions, 32 deletions
diff --git a/lib/Target/ARM/Thumb1FrameLowering.cpp b/lib/Target/ARM/Thumb1FrameLowering.cpp
index baa97a7..6deab4f 100644
--- a/lib/Target/ARM/Thumb1FrameLowering.cpp
+++ b/lib/Target/ARM/Thumb1FrameLowering.cpp
@@ -52,9 +52,9 @@ void Thumb1FrameLowering::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
const Thumb1InstrInfo &TII =
- *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo());
- const Thumb1RegisterInfo *RegInfo =
- static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo());
+ *static_cast<const Thumb1InstrInfo *>(MF.getSubtarget().getInstrInfo());
+ const Thumb1RegisterInfo *RegInfo = static_cast<const Thumb1RegisterInfo *>(
+ MF.getSubtarget().getRegisterInfo());
if (!hasReservedCallFrame(MF)) {
// If we have alloca, convert as follows:
// ADJCALLSTACKDOWN -> sub, sp, sp, amount
@@ -89,12 +89,15 @@ void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const {
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
- const Thumb1RegisterInfo *RegInfo =
- static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo());
+ const Thumb1RegisterInfo *RegInfo = static_cast<const Thumb1RegisterInfo *>(
+ MF.getSubtarget().getRegisterInfo());
const Thumb1InstrInfo &TII =
- *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo());
+ *static_cast<const Thumb1InstrInfo *>(MF.getSubtarget().getInstrInfo());
- unsigned Align = MF.getTarget().getFrameLowering()->getStackAlignment();
+ unsigned Align = MF.getTarget()
+ .getSubtargetImpl()
+ ->getFrameLowering()
+ ->getStackAlignment();
unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize(Align);
unsigned NumBytes = MFI->getStackSize();
assert(NumBytes >= ArgRegsSaveSize &&
@@ -321,12 +324,15 @@ void Thumb1FrameLowering::emitEpilogue(MachineFunction &MF,
DebugLoc dl = MBBI->getDebugLoc();
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- const Thumb1RegisterInfo *RegInfo =
- static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo());
+ const Thumb1RegisterInfo *RegInfo = static_cast<const Thumb1RegisterInfo *>(
+ MF.getSubtarget().getRegisterInfo());
const Thumb1InstrInfo &TII =
- *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo());
+ *static_cast<const Thumb1InstrInfo *>(MF.getSubtarget().getInstrInfo());
- unsigned Align = MF.getTarget().getFrameLowering()->getStackAlignment();
+ unsigned Align = MF.getTarget()
+ .getSubtargetImpl()
+ ->getFrameLowering()
+ ->getStackAlignment();
unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize(Align);
int NumBytes = (int)MFI->getStackSize();
assert((unsigned)NumBytes >= ArgRegsSaveSize &&
@@ -382,28 +388,65 @@ void Thumb1FrameLowering::emitEpilogue(MachineFunction &MF,
}
}
- if (ArgRegsSaveSize) {
- // Unlike T2 and ARM mode, the T1 pop instruction cannot restore
- // to LR, and we can't pop the value directly to the PC since
- // we need to update the SP after popping the value. Therefore, we
- // pop the old LR into R3 as a temporary.
-
+ bool IsV4PopReturn = false;
+ for (const CalleeSavedInfo &CSI : MFI->getCalleeSavedInfo())
+ if (CSI.getReg() == ARM::LR)
+ IsV4PopReturn = true;
+ IsV4PopReturn &= STI.hasV4TOps() && !STI.hasV5TOps();
+
+ // Unlike T2 and ARM mode, the T1 pop instruction cannot restore
+ // to LR, and we can't pop the value directly to the PC since
+ // we need to update the SP after popping the value. So instead
+ // we have to emit:
+ // POP {r3}
+ // ADD sp, #offset
+ // BX r3
+ // If this would clobber a return value, then generate this sequence instead:
+ // MOV ip, r3
+ // POP {r3}
+ // ADD sp, #offset
+ // MOV lr, r3
+ // MOV r3, ip
+ // BX lr
+ if (ArgRegsSaveSize || IsV4PopReturn) {
// Get the last instruction, tBX_RET
MBBI = MBB.getLastNonDebugInstr();
assert (MBBI->getOpcode() == ARM::tBX_RET);
- // Epilogue for vararg functions: pop LR to R3 and branch off it.
- AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tPOP)))
- .addReg(ARM::R3, RegState::Define);
-
- emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, ArgRegsSaveSize);
-
- MachineInstrBuilder MIB =
- BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX_RET_vararg))
- .addReg(ARM::R3, RegState::Kill);
- AddDefaultPred(MIB);
- MIB.copyImplicitOps(&*MBBI);
- // erase the old tBX_RET instruction
- MBB.erase(MBBI);
+ DebugLoc dl = MBBI->getDebugLoc();
+
+ if (AFI->getReturnRegsCount() <= 3) {
+ // Epilogue: pop saved LR to R3 and branch off it.
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tPOP)))
+ .addReg(ARM::R3, RegState::Define);
+
+ emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, ArgRegsSaveSize);
+
+ MachineInstrBuilder MIB =
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX))
+ .addReg(ARM::R3, RegState::Kill);
+ AddDefaultPred(MIB);
+ MIB.copyImplicitOps(&*MBBI);
+ // erase the old tBX_RET instruction
+ MBB.erase(MBBI);
+ } else {
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr))
+ .addReg(ARM::R12, RegState::Define)
+ .addReg(ARM::R3, RegState::Kill));
+
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tPOP)))
+ .addReg(ARM::R3, RegState::Define);
+
+ emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, ArgRegsSaveSize);
+
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr))
+ .addReg(ARM::LR, RegState::Define)
+ .addReg(ARM::R3, RegState::Kill));
+
+ AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr))
+ .addReg(ARM::R3, RegState::Define)
+ .addReg(ARM::R12, RegState::Kill));
+ // Keep the tBX_RET instruction
+ }
}
}
@@ -417,7 +460,7 @@ spillCalleeSavedRegisters(MachineBasicBlock &MBB,
DebugLoc DL;
MachineFunction &MF = *MBB.getParent();
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+ const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
if (MI != MBB.end()) DL = MI->getDebugLoc();
@@ -456,7 +499,7 @@ restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+ const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
bool isVarArg = AFI->getArgRegsSaveSize() > 0;
DebugLoc DL = MI->getDebugLoc();
@@ -470,6 +513,9 @@ restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
// Special epilogue for vararg functions. See emitEpilogue
if (isVarArg)
continue;
+ // ARMv4T requires BX, see emitEpilogue
+ if (STI.hasV4TOps() && !STI.hasV5TOps())
+ continue;
Reg = ARM::PC;
(*MIB).setDesc(TII.get(ARM::tPOP_RET));
MIB.copyImplicitOps(&*MI);
generated by cgit v1.1 at 2024-05-17 20:20:36 +0000