Make the clobber analysis a bit more smart: we only are careful about
early clobbers if the clobber list contains a *register* not some thing
like {memory}, {dirflag} etc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47457 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index e159c11..96dde98 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -3735,9 +3735,19 @@
SawEarlyClobber |= OpInfo.isEarlyClobber;
// If we see a clobber of a register, it is an early clobber.
- if (OpInfo.Type == InlineAsm::isClobber &&
- OpInfo.ConstraintType == TargetLowering::C_Register)
- SawEarlyClobber = true;
+ if (!SawEarlyClobber &&
+ OpInfo.Type == InlineAsm::isClobber &&
+ OpInfo.ConstraintType == TargetLowering::C_Register) {
+ // Note that we want to ignore things that we don't trick here, like
+ // dirflag, fpsr, flags, etc.
+ std::pair<unsigned, const TargetRegisterClass*> PhysReg =
+ TLI.getRegForInlineAsmConstraint(OpInfo.ConstraintCode,
+ OpInfo.ConstraintVT);
+ if (PhysReg.first || PhysReg.second) {
+ // This is a register we know of.
+ SawEarlyClobber = true;
+ }
+ }
// If this is a memory input, and if the operand is not indirect, do what we
// need to to provide an address for the memory input.