[InstCombine] Merge debug locations when folding through a phi node

If all the operands to a phi node are of the same operation, instcombine
will try to pull them through the phi node, combining them into a single
operation.  When it does this, the debug location of the operation should
be the merged debug locations of the phi node arguments.

Patch 3 of 8 for D26256.  Folding of a compare operation.

Differential Revision: https://reviews.llvm.org/D26256

llvm-svn: 289681

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
index 91bfe6c5c82..c288886fafb 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombinePHI.cpp
@@ -117,7 +117,7 @@ Instruction *InstCombiner::FoldPHIArgBinOpIntoPHI(PHINode &PN) {
   if (CmpInst *CIOp = dyn_cast<CmpInst>(FirstInst)) {
     CmpInst *NewCI = CmpInst::Create(CIOp->getOpcode(), CIOp->getPredicate(),
                                      LHSVal, RHSVal);
-    NewCI->setDebugLoc(FirstInst->getDebugLoc());
+    NewCI->setDebugLoc(PHIArgMergedDebugLoc(PN));
     return NewCI;
   }