Add back FoldOpIntoPhi optimizations with fix. Included test cases to help catch these errors and to test the presence of the optimization itself
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170248 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index c222495..47223c3 100644
--- a/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -354,6 +354,10 @@
if (Value *V = SimplifyFAddInst(LHS, RHS, I.getFastMathFlags(), TD))
return ReplaceInstUsesWith(I, V);
+ if (isa<Constant>(RHS) && isa<PHINode>(LHS))
+ if (Instruction *NV = FoldOpIntoPhi(I))
+ return NV;
+
// -A + B --> B - A
// -A + -B --> -(A + B)
if (Value *LHSV = dyn_castFNegVal(LHS))