diff test/Analysis/BasicAA/gcsetest.ll @ 0:95c75e76d11b LLVM3.4

LLVM 3.4
author Kaito Tokumori <e105711@ie.u-ryukyu.ac.jp>
date Thu, 12 Dec 2013 13:56:28 +0900
parents
children 60c9769439b8
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/Analysis/BasicAA/gcsetest.ll	Thu Dec 12 13:56:28 2013 +0900
@@ -0,0 +1,61 @@
+; Test that GCSE uses basicaa to do alias analysis, which is capable of 
+; disambiguating some obvious cases.  All loads should be removable in 
+; this testcase.
+
+; RUN: opt < %s -basicaa -gvn -instcombine -dce -S | FileCheck %s
+
+@A = global i32 7
+@B = global i32 8
+
+; CHECK:      define i32 @test()
+; CHECK-NEXT:   store i32 123, i32* @B
+; CHECK-NEXT:   ret i32 0
+
+define i32 @test() {
+	%A1 = load i32* @A
+
+	store i32 123, i32* @B  ; Store cannot alias @A
+
+	%A2 = load i32* @A
+	%X = sub i32 %A1, %A2
+	ret i32 %X
+}
+
+; CHECK:      define i32 @test2()
+; CHECK-NEXT:   br label %Loop
+; CHECK:      Loop:
+; CHECK-NEXT:   store i32 0, i32* @B
+; CHECK-NEXT:   br i1 true, label %out, label %Loop
+; CHECK:      out:
+; CHECK-NEXT:   ret i32 0
+
+define i32 @test2() {
+        %A1 = load i32* @A
+        br label %Loop
+Loop:
+        %AP = phi i32 [0, %0], [%X, %Loop]
+        store i32 %AP, i32* @B  ; Store cannot alias @A
+
+        %A2 = load i32* @A
+        %X = sub i32 %A1, %A2
+        %c = icmp eq i32 %X, 0
+        br i1 %c, label %out, label %Loop
+
+out:
+        ret i32 %X
+}
+
+declare void @external()
+
+; CHECK:      define i32 @test3()
+; CHECK-NEXT:   call void @external()
+; CHECK-NEXT:   ret i32 7
+
+define i32 @test3() {
+	%X = alloca i32
+	store i32 7, i32* %X
+	call void @external()
+	%V = load i32* %X
+	ret i32 %V
+}
+