diff options
Diffstat (limited to 'contrib/llvm/lib/Target/X86/X86RegisterInfo.cpp')
| -rw-r--r-- | contrib/llvm/lib/Target/X86/X86RegisterInfo.cpp | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/contrib/llvm/lib/Target/X86/X86RegisterInfo.cpp b/contrib/llvm/lib/Target/X86/X86RegisterInfo.cpp index dbda556b1b5e..e6cd59397cbd 100644 --- a/contrib/llvm/lib/Target/X86/X86RegisterInfo.cpp +++ b/contrib/llvm/lib/Target/X86/X86RegisterInfo.cpp @@ -403,18 +403,15 @@ bool X86RegisterInfo::hasBasePointer(const MachineFunction &MF) const { if (!EnableBasePointer) return false; - // When we need stack realignment and there are dynamic allocas, we can't - // reference off of the stack pointer, so we reserve a base pointer. - // - // This is also true if the function contain MS-style inline assembly. We - // do this because if any stack changes occur in the inline assembly, e.g., - // "pusha", then any C local variable or C argument references in the - // inline assembly will be wrong because the SP is not properly tracked. - if ((needsStackRealignment(MF) && MFI->hasVarSizedObjects()) || - MF.hasMSInlineAsm()) - return true; - - return false; + // When we need stack realignment, we can't address the stack from the frame + // pointer. When we have dynamic allocas or stack-adjusting inline asm, we + // can't address variables from the stack pointer. MS inline asm can + // reference locals while also adjusting the stack pointer. When we can't + // use both the SP and the FP, we need a separate base pointer register. + bool CantUseFP = needsStackRealignment(MF); + bool CantUseSP = + MFI->hasVarSizedObjects() || MFI->hasInlineAsmWithSPAdjust(); + return CantUseFP && CantUseSP; } bool X86RegisterInfo::canRealignStack(const MachineFunction &MF) const { |