From d4b0982cc0cc01d7b333dfc9610c3a42dd5ccafa Mon Sep 17 00:00:00 2001
From: Hideto Ueno <uenoku.tokotoko@gmail.com>
Date: Fri, 30 Aug 2019 10:00:32 +0000
Subject: [PATCH] [Attributor] Implement AANoAliasCallSiteArgument
 initialization

Summary: This patch adds an appropriate `initialize` method for `AANoAliasCallSiteArgument`.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D66927

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370456 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/IPO/Attributor.cpp                 |  6 ++++--
 test/Transforms/FunctionAttrs/noalias_returned.ll | 15 ++++++++++-----
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/lib/Transforms/IPO/Attributor.cpp b/lib/Transforms/IPO/Attributor.cpp
index dff7011061a..05686921a65 100644
--- a/lib/Transforms/IPO/Attributor.cpp
+++ b/lib/Transforms/IPO/Attributor.cpp
@@ -1592,8 +1592,10 @@ struct AANoAliasCallSiteArgument final : AANoAliasImpl {
 
   /// See AbstractAttribute::initialize(...).
   void initialize(Attributor &A) override {
-    // TODO: It isn't sound to initialize as the same with `AANoAliasImpl`
-    // because `noalias` may not be valid in the current position.
+    // See callsite argument attribute and callee argument attribute.
+    ImmutableCallSite ICS(&getAnchorValue());
+    if (ICS.paramHasAttr(getArgNo(), Attribute::NoAlias))
+      indicateOptimisticFixpoint();
   }
 
   /// See AbstractAttribute::updateImpl(...).
diff --git a/test/Transforms/FunctionAttrs/noalias_returned.ll b/test/Transforms/FunctionAttrs/noalias_returned.ll
index d7c4eadb983..ce28ed3f29a 100644
--- a/test/Transforms/FunctionAttrs/noalias_returned.ll
+++ b/test/Transforms/FunctionAttrs/noalias_returned.ll
@@ -142,8 +142,7 @@ define i8* @test8(i32* %0) nounwind uwtable {
 ; TEST 9
 ; Simple Argument Test
 define internal void @test9(i8* %a, i8* %b) {
-; FIXME: missing noalias
-; CHECK: define internal void @test9(i8* %a, i8* %b)
+; CHECK: define internal void @test9(i8* noalias %a, i8* %b)
   ret void
 }
 define void @test9_helper(i8* %a, i8* %b) {
@@ -156,12 +155,18 @@ define void @test9_helper(i8* %a, i8* %b) {
 ; TEST 10
 ; Simple CallSite Test
 
-declare void @test10_helper(i8* %a)
+declare void @test10_helper_1(i8* %a)
+define void @test10_helper_2(i8* noalias %a) {
+  ret void
+}
 define void @test10(i8* noalias %a) {
 ; CHECK: define void @test10(i8* noalias %a)
 ; FIXME: missing noalias
-; CHECK-NEXT:   tail call void @test10_helper(i8* %a)
-  tail call void @test10_helper(i8* %a)
+; CHECK-NEXT:   tail call void @test10_helper_1(i8* %a)
+  tail call void @test10_helper_1(i8* %a)
+
+; CHECK-NEXT:   tail call void @test10_helper_2(i8* noalias %a)
+  tail call void @test10_helper_2(i8* %a)
   ret void
 }
 
-- 
2.40.0