Commited patch from Björn Steinbrink:

Summary:
Different range metadata can lead to different optimizations in later
passes, possibly breaking the semantics of the merged function. So range
metadata must be taken into consideration when comparing Load
instructions.

Thanks!

llvm-svn: 211391

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
index c9b4af76913..c66df600700 100644
--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
@@ -325,6 +325,7 @@ private:
   /// 6.1.Load: volatile (as boolean flag)
   /// 6.2.Load: alignment (as integer numbers)
   /// 6.3.Load: synch-scope (as integer numbers)
+  /// 6.4.Load: range metadata (as integer numbers)
   /// On this stage its better to see the code, since its not more than 10-15
   /// strings for particular instruction, and could change sometimes.
   int cmpOperation(const Instruction *L, const Instruction *R) const;
@@ -788,7 +789,11 @@ int FunctionComparator::cmpOperation(const Instruction *L,
     if (int Res =
             cmpNumbers(LI->getOrdering(), cast<LoadInst>(R)->getOrdering()))
       return Res;
-    return cmpNumbers(LI->getSynchScope(), cast<LoadInst>(R)->getSynchScope());
+    if (int Res =
+            cmpNumbers(LI->getSynchScope(), cast<LoadInst>(R)->getSynchScope()))
+      return Res;
+    return cmpNumbers((uint64_t)LI->getMetadata(LLVMContext::MD_range),
+                      (uint64_t)cast<LoadInst>(R)->getMetadata(LLVMContext::MD_range));
   }
   if (const StoreInst *SI = dyn_cast<StoreInst>(L)) {
     if (int Res =