diff options
Diffstat (limited to 'lib/Target/ARM/Thumb1FrameLowering.cpp')
| -rw-r--r-- | lib/Target/ARM/Thumb1FrameLowering.cpp | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/lib/Target/ARM/Thumb1FrameLowering.cpp b/lib/Target/ARM/Thumb1FrameLowering.cpp index d4d59ea59d..9ff3ffcfa2 100644 --- a/lib/Target/ARM/Thumb1FrameLowering.cpp +++ b/lib/Target/ARM/Thumb1FrameLowering.cpp @@ -155,6 +155,27 @@ void Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const { AFI->setGPRCalleeSavedArea2Size(GPRCS2Size); AFI->setDPRCalleeSavedAreaSize(DPRCSSize); + if (RegInfo->needsStackRealignment(MF)) { + // We cannot use sp as source/dest register here, thus we're emitting the + // following sequence: + // mov r4, sp + // lsrs r4, r4, Log2MaxAlign + // lsls r4, r4, Log2MaxAlign + // mov sp, r4 + unsigned MaxAlign = MFI->getMaxAlignment(); + unsigned Log2MaxAlign = Log2_32(MaxAlign); + AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), ARM::R4) + .addReg(ARM::SP, RegState::Kill)); + AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tLSRri), ARM::R4)) + .addReg(ARM::R4, RegState::Kill) + .addImm(Log2MaxAlign)); + AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tLSLri), ARM::R4)) + .addReg(ARM::R4, RegState::Kill) + .addImm(Log2MaxAlign)); + AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), ARM::SP) + .addReg(ARM::R4, RegState::Kill)); + } + // If we need a base pointer, set it up here. It's whatever the value // of the stack pointer is at this point. Any variable size objects // will be allocated after this, so we can still use the base pointer |