From 892b84007c980e58181cd94fea7d70c5ed9642c8 Mon Sep 17 00:00:00 2001
From: Duncan Sands <baldrick@free.fr>
Date: Thu, 11 Sep 2008 19:35:55 +0000
Subject: [PATCH] Intrinsics don't touch internal global variables (unless
 passed one via a parameter), even if they are IntrWriteMem.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56115 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Analysis/IPA/GlobalsModRef.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/Analysis/IPA/GlobalsModRef.cpp b/lib/Analysis/IPA/GlobalsModRef.cpp
index 6063a1d16b7..6736e6f3ce4 100644
--- a/lib/Analysis/IPA/GlobalsModRef.cpp
+++ b/lib/Analysis/IPA/GlobalsModRef.cpp
@@ -392,8 +392,10 @@ void GlobalsModRef::AnalyzeCallGraph(CallGraph &CG, Module &M) {
               FR.GlobalInfo[*GI] |= Ref;
           }
         } else {
-          // Can't say anything useful.
-          KnowNothing = true;
+          FunctionEffect |= ModRef;
+          // Can't say anything useful unless it's an intrinsic - they don't
+          // read or write global variables of the kind considered here.
+          KnowNothing = !F->isIntrinsic();
         }
         continue;
       }
-- 
2.34.1