[InstCombine] Fix extractelement use before def

This fixes a bug that can cause extractelements with operands that
haven't been defined yet to be inserted at a wrong point when
optimising insertelements.

Patch by Karl Hylen.

Differential Revision: https://reviews.llvm.org/D33449

llvm-svn: 304701

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
index 7fc6774f184..abfa39ded99 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineVectorOps.cpp
@@ -440,7 +440,7 @@ static void replaceExtractElements(InsertElementInst *InsElt,
     if (!OldExt || OldExt->getParent() != WideVec->getParent())
       continue;
     auto *NewExt = ExtractElementInst::Create(WideVec, OldExt->getOperand(1));
-    NewExt->insertAfter(WideVec);
+    NewExt->insertAfter(OldExt);
     IC.replaceInstUsesWith(*OldExt, NewExt);
   }
 }