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Fix for PR1348. If stack inc / dec amount is > 32-bits, issue a series of add / sub instructions. 

llvm-svn: 36456
This commit is contained in:
Evan Cheng 2007-04-26 01:09:28 +00:00
parent 9f12bc480b
commit ce6e6db704
1 changed files with 27 additions and 18 deletions
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45
llvm/lib/Target/X86/X86RegisterInfo.cpp
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@ -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);
}
}
}