When substituting sunkaddrs into indirect arguments an asm, we were

walking the asm arguments once and stashing their Values.  This is
wrong because the same memory location can be in the list twice, and
if the first one has a sunkaddr substituted, the stashed value for the
second one will be wrong (use-after-free).  PR 8154.

llvm-svn: 114104

1 files changed, 4 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp b/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp
index 02282820fc9..437de38131c 100644
--- a/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/llvm/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -738,6 +738,7 @@ bool CodeGenPrepare::OptimizeInlineAsmInst(Instruction *I, CallSite CS,
   bool MadeChange = false;
 
   std::vector<TargetLowering::AsmOperandInfo> TargetConstraints = TLI->ParseConstraints(CS);
+  unsigned ArgNo = 0;
   for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
     TargetLowering::AsmOperandInfo &OpInfo = TargetConstraints[i];
     
@@ -746,9 +747,10 @@ bool CodeGenPrepare::OptimizeInlineAsmInst(Instruction *I, CallSite CS,
 
     if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
         OpInfo.isIndirect) {
-      Value *OpVal = OpInfo.CallOperandVal;
+      Value *OpVal = const_cast<Value *>(CS.getArgument(ArgNo++));
       MadeChange |= OptimizeMemoryInst(I, OpVal, OpVal->getType(), SunkAddrs);
-    }
+    } else if (OpInfo.Type == InlineAsm::isInput)
+      ArgNo++;
   }
 
   return MadeChange;