Fix PR1850 by removing an unsafe transformation from VMCore/ConstantFold.cpp.

Reimplement the xform in Analysis/ConstantFolding.cpp where we can use
targetdata to validate that it is safe.  While I'm in there, fix some const
correctness issues and generalize the interface to the "operand folder".

llvm-svn: 44817

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index f05085fca16..e85fe8e40a0 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -299,7 +299,13 @@ ConstantFoldMappedInstruction(const Instruction *I) {
     else
       return 0;  // All operands not constant!
 
-  return ConstantFoldInstOperands(I, &Ops[0], Ops.size(), TD);
+  
+  if (const CmpInst *CI = dyn_cast<CmpInst>(I))
+    return ConstantFoldCompareInstOperands(CI->getPredicate(),
+                                           &Ops[0], Ops.size(), TD);
+  else
+    return ConstantFoldInstOperands(I->getOpcode(), I->getType(),
+                                    &Ops[0], Ops.size(), TD);
 }
 
 /// CloneAndPruneFunctionInto - This works exactly like CloneFunctionInto,