RPCS3/llvm
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm.git synced 2024-12-23 04:28:30 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Cygwin support: use _alloca to allocate stack if > 4k. Patch by Anton Korobeynikov.

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28764 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2006-06-13 05:14:44 +00:00
parent 9686ae7f4e
commit 004fb92615
1 changed files with 21 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
lib/Target/X86/X86RegisterInfo.cpp
View File

@ -760,10 +760,21 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
MFI->setStackSize(NumBytes);
if (NumBytes) { // adjust stack pointer: ESP -= numbytes
if (NumBytes >= 4096 && Subtarget->TargetType == X86Subtarget::isCygwin) {
// Function prologue calls _alloca to probe the stack when allocating
// more than 4k bytes in one go. Touching the stack at 4K increments is
// necessary to ensure that the guard pages used by the OS virtual memory
// manager are allocated in correct sequence.
MI = BuildMI(X86::MOV32ri, 2, X86::EAX).addImm(NumBytes);
MBB.insert(MBBI, MI);
MI = BuildMI(X86::CALLpcrel32, 1).addExternalSymbol("_alloca");
MBB.insert(MBBI, MI);
} else {
unsigned Opc = NumBytes < 128 ? X86::SUB32ri8 : X86::SUB32ri;
MI = BuildMI(Opc, 1, X86::ESP,MachineOperand::UseAndDef).addImm(NumBytes);
MBB.insert(MBBI, MI);
}
}
if (hasFP(MF)) {
// Get the offset of the stack slot for the EBP register... which is
@ -789,6 +800,12 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
Subtarget->TargetType == X86Subtarget::isCygwin) {
MI = BuildMI(X86::AND32ri, 2, X86::ESP).addImm(-Align);
MBB.insert(MBBI, MI);
// Probe the stack
MI = BuildMI(X86::MOV32ri, 2, X86::EAX).addImm(Align);
MBB.insert(MBBI, MI);
MI = BuildMI(X86::CALLpcrel32, 1).addExternalSymbol("_alloca");
MBB.insert(MBBI, MI);
}
}