From ea8900f5df76e11efb9464157af160f5fa41e9c0 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Mon, 8 Nov 2010 17:12:04 +0000
Subject: [PATCH] Make FunctionAttrs TBAA-aware.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@118417 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/IPO/FunctionAttrs.cpp          | 36 ++++++++++++------
 .../TypeBasedAliasAnalysis/functionattrs.ll   | 37 +++++++++++++++++++
 2 files changed, 61 insertions(+), 12 deletions(-)
 create mode 100644 test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll

diff --git a/lib/Transforms/IPO/FunctionAttrs.cpp b/lib/Transforms/IPO/FunctionAttrs.cpp
index be5d827e8e5..c4978b4df56 100644
--- a/lib/Transforms/IPO/FunctionAttrs.cpp
+++ b/lib/Transforms/IPO/FunctionAttrs.cpp
@@ -23,6 +23,7 @@
 #include "llvm/CallGraphSCCPass.h"
 #include "llvm/GlobalVariable.h"
 #include "llvm/IntrinsicInst.h"
+#include "llvm/LLVMContext.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/CaptureTracking.h"
@@ -140,10 +141,14 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
           for (CallSite::arg_iterator CI = CS.arg_begin(), CE = CS.arg_end();
                CI != CE; ++CI) {
             Value *Arg = *CI;
-            if (Arg->getType()->isPointerTy() &&
-                !AA->pointsToConstantMemory(Arg, /*OrLocal=*/true))
-              // Writes memory.  Just give up.
-              return false;
+            if (Arg->getType()->isPointerTy()) {
+              AliasAnalysis::Location Loc(Arg,
+                                          AliasAnalysis::UnknownSize,
+                                          I->getMetadata(LLVMContext::MD_tbaa));
+              if (!AA->pointsToConstantMemory(Arg, /*OrLocal=*/true))
+                // Writes memory.  Just give up.
+                return false;
+            }
           }
           // Only reads and writes local memory.
           continue;
@@ -153,16 +158,23 @@ bool FunctionAttrs::AddReadAttrs(const CallGraphSCC &SCC) {
         }
       } else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
         // Ignore non-volatile loads from local memory.
-        if (!LI->isVolatile() &&
-            AA->pointsToConstantMemory(LI->getPointerOperand(),
-                                       /*OrLocal=*/true))
-          continue;
+        if (!LI->isVolatile()) {
+          AliasAnalysis::Location Loc(LI->getPointerOperand(),
+                                        AA->getTypeStoreSize(LI->getType()),
+                                        LI->getMetadata(LLVMContext::MD_tbaa));
+          if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
+            continue;
+        }
       } else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
         // Ignore non-volatile stores to local memory.
-        if (!SI->isVolatile() &&
-            AA->pointsToConstantMemory(SI->getPointerOperand(),
-                                       /*OrLocal=*/true))
-          continue;
+        if (!SI->isVolatile()) {
+          const Type *StoredType = SI->getValueOperand()->getType();
+          AliasAnalysis::Location Loc(SI->getPointerOperand(),
+                                      AA->getTypeStoreSize(StoredType),
+                                      SI->getMetadata(LLVMContext::MD_tbaa));
+          if (AA->pointsToConstantMemory(Loc, /*OrLocal=*/true))
+            continue;
+        }
       }
 
       // Any remaining instructions need to be taken seriously!  Check if they
diff --git a/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll b/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll
new file mode 100644
index 00000000000..62fe8aa1644
--- /dev/null
+++ b/test/Analysis/TypeBasedAliasAnalysis/functionattrs.ll
@@ -0,0 +1,37 @@
+; RUN: opt < %s -enable-tbaa -tbaa -basicaa -functionattrs -S | FileCheck %s
+
+; FunctionAttrs should make use of TBAA.
+
+; CHECK: define void @test0_yes(i32* nocapture %p) nounwind readnone {
+define void @test0_yes(i32* %p) nounwind {
+  store i32 0, i32* %p, !tbaa !1
+  ret void
+}
+
+; CHECK: define void @test0_no(i32* nocapture %p) nounwind {
+define void @test0_no(i32* %p) nounwind {
+  store i32 0, i32* %p, !tbaa !2
+  ret void
+}
+
+; CHECK: define void @test1_yes(i32* %p) nounwind readonly {
+define void @test1_yes(i32* %p) nounwind {
+  call void @callee(i32* %p), !tbaa !1
+  ret void
+}
+
+; CHECK: define void @test1_no(i32* %p) nounwind {
+define void @test1_no(i32* %p) nounwind {
+  call void @callee(i32* %p), !tbaa !2
+  ret void
+}
+
+declare void @callee(i32* %p) nounwind
+
+; Root note.
+!0 = metadata !{ }
+
+; Invariant memory.
+!1 = metadata !{ metadata !"foo", metadata !0, i1 1 }
+; Not invariant memory.
+!2 = metadata !{ metadata !"foo", metadata !0, i1 0 }
-- 
2.34.1