From: Nuno Lopes <nunoplopes@sapo.pt>
Date: Wed, 9 Aug 2017 17:02:18 +0000 (+0000)
Subject: CFLAA: return MustAlias when pointers p, q are equal, i.e.,
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=cf10b736fb9222773467c54c322c6af99d2fd6a5;p=llvm

CFLAA: return MustAlias when pointers p, q are equal, i.e.,
must-alias(p, sz_p, p, sz_q)  irrespective of access sizes sz_p, sz_q

As discussed a couple of weeks ago on the ML.
This makes the behavior consistent with that of BasicAA.
AA clients already check the obj size themselves and may not require the
obj size to match exactly the access size (e.g., in case of store forwarding)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310495 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/Analysis/CFLSteensAliasAnalysis.h b/include/llvm/Analysis/CFLSteensAliasAnalysis.h
index fd3fa5febcd..03ce85aa97b 100644
--- a/include/llvm/Analysis/CFLSteensAliasAnalysis.h
+++ b/include/llvm/Analysis/CFLSteensAliasAnalysis.h
@@ -68,7 +68,7 @@ public:
 
   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
     if (LocA.Ptr == LocB.Ptr)
-      return LocA.Size == LocB.Size ? MustAlias : PartialAlias;
+      return MustAlias;
 
     // Comparisons between global variables and other constants should be
     // handled by BasicAA.
diff --git a/lib/Analysis/CFLAndersAliasAnalysis.cpp b/lib/Analysis/CFLAndersAliasAnalysis.cpp
index 0de7ad98af4..1a3998836cf 100644
--- a/lib/Analysis/CFLAndersAliasAnalysis.cpp
+++ b/lib/Analysis/CFLAndersAliasAnalysis.cpp
@@ -837,7 +837,7 @@ AliasResult CFLAndersAAResult::query(const MemoryLocation &LocA,
 AliasResult CFLAndersAAResult::alias(const MemoryLocation &LocA,
                                      const MemoryLocation &LocB) {
   if (LocA.Ptr == LocB.Ptr)
-    return LocA.Size == LocB.Size ? MustAlias : PartialAlias;
+    return MustAlias;
 
   // Comparisons between global variables and other constants should be
   // handled by BasicAA.