diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/X86/X86RegisterInfo.cpp | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp index 25fa3d66e6..e923606021 100644 --- a/lib/Target/X86/X86RegisterInfo.cpp +++ b/lib/Target/X86/X86RegisterInfo.cpp @@ -1500,6 +1500,31 @@ void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI, } } +// mergeSPUpdatesUp - Merge two stack-manipulating instructions lower iterator. +static +void mergeSPUpdatesDown(MachineBasicBlock &MBB,MachineBasicBlock::iterator &MBBI, + unsigned StackPtr, uint64_t *NumBytes = NULL) { + if (MBBI != MBB.end()) { + MachineBasicBlock::iterator NI = next(MBBI); + unsigned Opc = NI->getOpcode(); + if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 || + Opc == X86::ADD32ri || Opc == X86::ADD32ri8) && + NI->getOperand(0).getReg() == StackPtr) { + if (NumBytes) + *NumBytes -= NI->getOperand(2).getImm(); + MBB.erase(NI); + MBBI = NI; + } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 || + Opc == X86::SUB32ri || Opc == X86::SUB32ri8) && + NI->getOperand(0).getReg() == StackPtr) { + if (NumBytes) + *NumBytes += NI->getOperand(2).getImm(); + MBB.erase(NI); + MBBI = NI; + } + } +} + void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB MachineFrameInfo *MFI = MF.getFrameInfo(); @@ -1585,9 +1610,9 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { MBB.insert(MBBI, MI); } } else { - // If there is an ADD32ri or SUB32ri of ESP immediately before this + // If there is an ADD32ri or SUB32ri of ESP immediately after this // instruction, merge the two instructions. - mergeSPUpdatesUp(MBB, MBBI, StackPtr, &NumBytes); + mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes); if (NumBytes) emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII); |