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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@194846 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 57 insertions, 3 deletions

diff --git a/lib/Transforms/IPO/ArgumentPromotion.cpp b/lib/Transforms/IPO/ArgumentPromotion.cpp
index 65c57e1df5..df08091ac5 100644
--- a/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/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();
diff --git a/test/Transforms/ArgumentPromotion/reserve-tbaa.ll b/test/Transforms/ArgumentPromotion/reserve-tbaa.ll
new file mode 100644
index 0000000000..4688a83f24
--- /dev/null
+++ b/test/Transforms/ArgumentPromotion/reserve-tbaa.ll
@@ -0,0 +1,52 @@
+; RUN: opt < %s -argpromotion -S
+
+; PR17906
+; When we promote two arguments in a single function with different types,
+; before the fix, we used the same tag for the newly-created two loads.
+; This testing case makes sure that we correctly transfer the tbaa tags from the
+; original loads to the newly-created loads when promoting pointer arguments.
+
+@a = global i32* null, align 8
+@e = global i32** @a, align 8
+@g = global i32 0, align 4
+@c = global i64 0, align 8
+@d = global i8 0, align 1
+
+define internal fastcc void @fn(i32* nocapture readonly %p1, i64* nocapture readonly %p2) {
+entry:
+  %0 = load i64* %p2, align 8, !tbaa !1
+  %conv = trunc i64 %0 to i32
+  %1 = load i32* %p1, align 4, !tbaa !5
+  %conv1 = trunc i32 %1 to i8
+  store i8 %conv1, i8* @d, align 1, !tbaa !7
+  ret void
+}
+
+define i32 @main() {
+entry:
+; CHECK-LABEL: main
+; CHECK: store i32 1, i32* %{{.*}}, align 4, !tbaa ![[I32:[0-9]+]]
+; CHECK: %g.val = load i32* @g, align 4, !tbaa ![[I32]]
+; CHECK: %c.val = load i64* @c, align 8, !tbaa ![[LONG:[0-9]+]]
+  %0 = load i32*** @e, align 8, !tbaa !8
+  store i32* @g, i32** %0, align 8, !tbaa !8
+  %1 = load i32** @a, align 8, !tbaa !8
+  store i32 1, i32* %1, align 4, !tbaa !5
+  call fastcc void @fn(i32* @g, i64* @c)
+
+  ret i32 0
+}
+
+!1 = metadata !{metadata !2, metadata !2, i64 0}
+!2 = metadata !{metadata !"long", metadata !3, i64 0}
+!3 = metadata !{metadata !"omnipotent char", metadata !4, i64 0}
+!4 = metadata !{metadata !"Simple C/C++ TBAA"}
+!5 = metadata !{metadata !6, metadata !6, i64 0}
+!6 = metadata !{metadata !"int", metadata !3, i64 0}
+!7 = metadata !{metadata !3, metadata !3, i64 0}
+!8 = metadata !{metadata !9, metadata !9, i64 0}
+!9 = metadata !{metadata !"any pointer", metadata !3, i64 0}
+; CHECK: ![[I32]] = metadata !{metadata ![[I32_TYPE:[0-9]+]], metadata ![[I32_TYPE]], i64 0}
+; CHECK: ![[I32_TYPE]] = metadata !{metadata !"int", metadata !{{.*}}, i64 0}
+; CHECK: ![[LONG]] = metadata !{metadata ![[LONG_TYPE:[0-9]+]], metadata ![[LONG_TYPE]], i64 0}
+; CHECK: ![[LONG_TYPE]] = metadata !{metadata !"long", metadata !{{.*}}, i64 0}