diff options
| -rw-r--r-- | lib/Target/X86/X86RegisterInfo.cpp | 45 |
1 files changed, 27 insertions, 18 deletions
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp index ee74d1afeb..52ab7f0945 100644 --- a/lib/Target/X86/X86RegisterInfo.cpp +++ b/lib/Target/X86/X86RegisterInfo.cpp @@ -1023,6 +1023,30 @@ X86RegisterInfo::processFunctionBeforeFrameFinalized(MachineFunction &MF) const{ } } +/// emitSPUpdate - Emit a series of instructions to increment / decrement the +/// stack pointer by a constant value. +static +void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI, + unsigned StackPtr, int64_t NumBytes, bool Is64Bit, + const TargetInstrInfo &TII) { + bool isSub = NumBytes < 0; + uint64_t Offset = isSub ? -NumBytes : NumBytes; + unsigned Opc = isSub + ? ((Offset < 128) ? + (Is64Bit ? X86::SUB64ri8 : X86::SUB32ri8) : + (Is64Bit ? X86::SUB64ri32 : X86::SUB32ri)) + : ((Offset < 128) ? + (Is64Bit ? X86::ADD64ri8 : X86::ADD32ri8) : + (Is64Bit ? X86::ADD64ri32 : X86::ADD32ri)); + uint64_t Chunk = (1LL << 31) - 1; + + while (Offset) { + uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset; + BuildMI(MBB, MBBI, TII.get(Opc), StackPtr).addReg(StackPtr).addImm(ThisVal); + Offset -= ThisVal; + } +} + void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB MachineBasicBlock::iterator MBBI = MBB.begin(); @@ -1075,11 +1099,7 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const { MBB.insert(MBBI, MI); } } else { - unsigned Opc = (NumBytes < 128) ? - (Is64Bit ? X86::SUB64ri8 : X86::SUB32ri8) : - (Is64Bit ? X86::SUB64ri32 : X86::SUB32ri); - MI= BuildMI(TII.get(Opc), StackPtr).addReg(StackPtr).addImm(NumBytes); - MBB.insert(MBBI, MI); + emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII); } } @@ -1206,19 +1226,8 @@ void X86RegisterInfo::emitEpilogue(MachineFunction &MF, } } - if (NumBytes > 0) { - unsigned Opc = (NumBytes < 128) ? - (Is64Bit ? X86::ADD64ri8 : X86::ADD32ri8) : - (Is64Bit ? X86::ADD64ri32 : X86::ADD32ri); - BuildMI(MBB, MBBI, TII.get(Opc), StackPtr) - .addReg(StackPtr).addImm(NumBytes); - } else if ((int)NumBytes < 0) { - unsigned Opc = (-NumBytes < 128) ? - (Is64Bit ? X86::SUB64ri8 : X86::SUB32ri8) : - (Is64Bit ? X86::SUB64ri32 : X86::SUB32ri); - BuildMI(MBB, MBBI, TII.get(Opc), StackPtr) - .addReg(StackPtr).addImm(-NumBytes); - } + if (NumBytes) + emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII); } } } |