From c2d93c404820178d55f440d4aa46e75d4b5c7b64 Mon Sep 17 00:00:00 2001
From: Arnold Schwaighofer <aschwaighofer@apple.com>
Date: Thu, 26 Jun 2014 19:51:19 +0000
Subject: GVN: Preserve invariant.load metadata

If both instructions to be replaced are marked invariant the resulting
instruction is invariant.

rdar://13358910

Fix by Erik Eckstein!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211801 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Scalar/GVN.cpp | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'lib/Transforms')

diff --git a/lib/Transforms/Scalar/GVN.cpp b/lib/Transforms/Scalar/GVN.cpp
index 56781d44aa..106eba099c 100644
--- a/lib/Transforms/Scalar/GVN.cpp
+++ b/lib/Transforms/Scalar/GVN.cpp
@@ -1798,6 +1798,10 @@ static void patchReplacementInstruction(Instruction *I, Value *Repl) {
       case LLVMContext::MD_fpmath:
         ReplInst->setMetadata(Kind, MDNode::getMostGenericFPMath(IMD, ReplMD));
         break;
+      case LLVMContext::MD_invariant_load:
+        // Only set the !invariant.load if it is present in both instructions.
+        ReplInst->setMetadata(Kind, IMD);
+        break;
       }
     }
   }
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