From 107f41fad5f8df734c72cf39a016a7ea0d874388 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Wed, 19 Aug 2009 00:11:12 +0000
Subject: Fix SimplifyLibcalls and ValueTracking to check mayBeOverridden
 before performing optimizations based on constant string values.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79384 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/SimplifyLibCalls/weak-symbols.ll | 26 ++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 test/Transforms/SimplifyLibCalls/weak-symbols.ll

(limited to 'test')

diff --git a/test/Transforms/SimplifyLibCalls/weak-symbols.ll b/test/Transforms/SimplifyLibCalls/weak-symbols.ll
new file mode 100644
index 0000000000..970ee0ddf1
--- /dev/null
+++ b/test/Transforms/SimplifyLibCalls/weak-symbols.ll
@@ -0,0 +1,26 @@
+; RUN: llvm-as < %s | opt -simplify-libcalls | llvm-dis | FileCheck %s
+; PR4738
+
+; SimplifyLibcalls shouldn't assume anything about weak symbols.
+
+@real_init = weak_odr constant [2 x i8] c"y\00"
+@fake_init = weak constant [2 x i8] c"y\00"
+@.str = private constant [2 x i8] c"y\00"
+
+; CHECK: define i32 @foo
+; CHECK: call i32 @strcmp
+define i32 @foo() nounwind {
+entry:
+  %t0 = call i32 @strcmp(i8* getelementptr inbounds ([2 x i8]* @fake_init, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8]* @.str, i64 0, i64 0)) nounwind readonly
+  ret i32 %t0
+}
+
+; CHECK: define i32 @bar
+; CHECK: ret i32 0
+define i32 @bar() nounwind {
+entry:
+  %t0 = call i32 @strcmp(i8* getelementptr inbounds ([2 x i8]* @real_init, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8]* @.str, i64 0, i64 0)) nounwind readonly
+  ret i32 %t0
+}
+
+declare i32 @strcmp(i8*, i8*) nounwind readonly
-- 
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