diff options
Diffstat (limited to 'llvm/lib/Target/X86/X86CallFrameOptimization.cpp')
| -rw-r--r-- | llvm/lib/Target/X86/X86CallFrameOptimization.cpp | 20 |
1 files changed, 10 insertions, 10 deletions
diff --git a/llvm/lib/Target/X86/X86CallFrameOptimization.cpp b/llvm/lib/Target/X86/X86CallFrameOptimization.cpp index 4b00355d09c..b16fa76c73f 100644 --- a/llvm/lib/Target/X86/X86CallFrameOptimization.cpp +++ b/llvm/lib/Target/X86/X86CallFrameOptimization.cpp @@ -346,15 +346,15 @@ void X86CallFrameOptimization::collectCallInfo(MachineFunction &MF, while (I->getOpcode() == X86::LEA32r) ++I; - // We expect a copy instruction here. - // TODO: The copy instruction is a lowering artifact. - // We should also support a copy-less version, where the stack - // pointer is used directly. - if (!I->isCopy() || !I->getOperand(0).isReg()) - return; - Context.SPCopy = &*I++; - - unsigned StackPtr = Context.SPCopy->getOperand(0).getReg(); + unsigned StackPtr = RegInfo.getStackRegister(); + // SelectionDAG (but not FastISel) inserts a copy of ESP into a virtual + // register here. If it's there, use that virtual register as stack pointer + // instead. + if (I->isCopy() && I->getOperand(0).isReg() && I->getOperand(1).isReg() && + I->getOperand(1).getReg() == StackPtr) { + Context.SPCopy = &*I++; + StackPtr = Context.SPCopy->getOperand(0).getReg(); + } // Scan the call setup sequence for the pattern we're looking for. // We only handle a simple case - a sequence of store instructions that @@ -539,7 +539,7 @@ void X86CallFrameOptimization::adjustCallSequence(MachineFunction &MF, // The stack-pointer copy is no longer used in the call sequences. // There should not be any other users, but we can't commit to that, so: - if (MRI->use_empty(Context.SPCopy->getOperand(0).getReg())) + if (Context.SPCopy && MRI->use_empty(Context.SPCopy->getOperand(0).getReg())) Context.SPCopy->eraseFromParent(); // Once we've done this, we need to make sure PEI doesn't assume a reserved |
