; disambiguating some obvious cases. All loads should be removable in
; this testcase.
-; RUN: if as < %s | opt -basicaa -gcse -instcombine -dce | dis | grep load
-; RUN: then exit 1
-; RUN: else exit 0
-; RUN: fi
+; RUN: opt < %s -basicaa -gvn -instcombine -dce -S | FileCheck %s
-%A = global int 7
-%B = global int 8
-implementation
+@A = global i32 7
+@B = global i32 8
-int %test() {
- %A1 = load int* %A
+; CHECK: define i32 @test()
+; CHECK-NEXT: store i32 123, i32* @B
+; CHECK-NEXT: ret i32 0
- store int 123, int* %B ; Store cannot alias %A
+define i32 @test() {
+ %A1 = load i32* @A
- %A2 = load int* %A
- %X = sub int %A1, %A2
- ret int %X
+ 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
}