From 8f3fabe0febb7335c4349d3d6081deca95419d48 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 28 Mar 2012 21:31:24 +0000
Subject: [PATCH] Handle intrinsics in GlobalsModRef. Fixes pr12351.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153604 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/IPA/GlobalsModRef.cpp     |  6 +++++
 test/Analysis/GlobalsModRef/pr12351.ll | 33 ++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)
 create mode 100644 test/Analysis/GlobalsModRef/pr12351.ll

diff --git a/lib/Analysis/IPA/GlobalsModRef.cpp b/lib/Analysis/IPA/GlobalsModRef.cpp
index b226d66cd78..c1d8e3e65a6 100644
--- a/lib/Analysis/IPA/GlobalsModRef.cpp
+++ b/lib/Analysis/IPA/GlobalsModRef.cpp
@@ -21,6 +21,7 @@
 #include "llvm/Instructions.h"
 #include "llvm/Constants.h"
 #include "llvm/DerivedTypes.h"
+#include "llvm/IntrinsicInst.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
@@ -467,6 +468,11 @@ void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
         } else if (isMalloc(&cast<Instruction>(*II)) ||
                    isFreeCall(&cast<Instruction>(*II))) {
           FunctionEffect |= ModRef;
+        } else if (IntrinsicInst *Intrinsic = dyn_cast<IntrinsicInst>(&*II)) {
+          // The callgraph doesn't include intrinsic calls.
+          Function *Callee = Intrinsic->getCalledFunction();
+          ModRefBehavior Behaviour = AliasAnalysis::getModRefBehavior(Callee);
+          FunctionEffect |= (Behaviour & ModRef);
         }
 
     if ((FunctionEffect & Mod) == 0)
diff --git a/test/Analysis/GlobalsModRef/pr12351.ll b/test/Analysis/GlobalsModRef/pr12351.ll
new file mode 100644
index 00000000000..1c5ac43f8d2
--- /dev/null
+++ b/test/Analysis/GlobalsModRef/pr12351.ll
@@ -0,0 +1,33 @@
+; RUN: opt < %s -basicaa -globalsmodref-aa -gvn -S | FileCheck %s
+
+declare void @llvm.memcpy.p0i8.p0i8.i32(i8*, i8*, i32, i32, i1)
+define void @foo(i8* %x, i8* %y) {
+  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %x, i8* %y, i32 1, i32 1, i1 false);
+  ret void
+}
+
+define void @bar(i8* %y, i8* %z) {
+  %x = alloca i8
+  call void @foo(i8* %x, i8* %y)
+  %t = load i8* %x
+  store i8 %t, i8* %y
+; CHECK: store i8 %t, i8* %y
+  ret void
+}
+
+
+define i32 @foo2() {
+  %foo = alloca i32
+  call void @bar2(i32* %foo)
+  %t0 = load i32* %foo, align 4
+; CHECK: %t0 = load i32* %foo, align 4
+  ret i32 %t0
+}
+
+define void @bar2(i32* %foo)  {
+  store i32 0, i32* %foo, align 4
+  tail call void @llvm.dbg.value(metadata !{}, i64 0, metadata !{})
+  ret void
+}
+
+declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
-- 
2.34.1