diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp index 5204113b3aa..b20f061e03c 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp @@ -5111,7 +5111,9 @@ void SelectionDAGLowering::visitInlineAsm(CallSite CS) { /// ConstraintOperands - Information about all of the constraints. std::vector<SDISelAsmOperandInfo> ConstraintOperands; - SDValue Chain = getRoot(); + // We won't need to flush pending loads if this asm doesn't touch + // memory and is nonvolatile. + SDValue Chain = IA->hasSideEffects() ? getRoot() : DAG.getRoot(); SDValue Flag; std::set<unsigned> OutputRegs, InputRegs; @@ -5122,6 +5124,10 @@ void SelectionDAGLowering::visitInlineAsm(CallSite CS) { ConstraintInfos = IA->ParseConstraints(); bool hasMemory = hasInlineAsmMemConstraint(ConstraintInfos, TLI); + // Flush pending loads if this touches memory (includes clobbering it). + // It's possible this is overly conservative. + if (hasMemory) + Chain = getRoot(); unsigned ArgNo = 0; // ArgNo - The argument of the CallInst. unsigned ResNo = 0; // ResNo - The result number of the next output. |
