ArgumentPromotion: correctly transfer TBAA tags and alignments.

We used to use std::map<IndicesVector, LoadInst*> for OriginalLoads, and when we
try to promote two arguments, they will both write to OriginalLoads causing
created loads for the two arguments to have the same original load. And the same
tbaa tag and alignment will be put to the created loads for the two arguments.

The fix is to use std::map<std::pair<Argument*, IndicesVector>, LoadInst*>
for OriginalLoads, so each Argument will write to different parts of the map.

PR17906

llvm-svn: 194846

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index 65c57e1df50..df08091ac5b 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -504,7 +504,9 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
   // OriginalLoads - Keep track of a representative load instruction from the
   // original function so that we can tell the alias analysis implementation
   // what the new GEP/Load instructions we are inserting look like.
-  std::map<IndicesVector, LoadInst*> OriginalLoads;
+  // We need to keep the original loads for each argument and the elements
+  // of the argument that are accessed.
+  std::map<std::pair<Argument*, IndicesVector>, LoadInst*> OriginalLoads;
 
   // Attribute - Keep track of the parameter attributes for the arguments
   // that we are *not* promoting. For the ones that we do promote, the parameter
@@ -569,7 +571,7 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
         else
           // Take any load, we will use it only to update Alias Analysis
           OrigLoad = cast<LoadInst>(User->use_back());
-        OriginalLoads[Indices] = OrigLoad;
+        OriginalLoads[std::make_pair(I, Indices)] = OrigLoad;
       }
 
       // Add a parameter to the function for each element passed in.
@@ -676,7 +678,7 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
         for (ScalarizeTable::iterator SI = ArgIndices.begin(),
                E = ArgIndices.end(); SI != E; ++SI) {
           Value *V = *AI;
-          LoadInst *OrigLoad = OriginalLoads[*SI];
+          LoadInst *OrigLoad = OriginalLoads[std::make_pair(I, *SI)];
           if (!SI->empty()) {
             Ops.reserve(SI->size());
             Type *ElTy = V->getType();