1 files changed, 46 insertions, 0 deletions
diff --git a/test/Analysis/BasicAA/gcsetest.ll b/test/Analysis/BasicAA/gcsetest.ll
new file mode 100644
index 0000000..a903362
--- /dev/null
+++ b/test/Analysis/BasicAA/gcsetest.ll
@@ -0,0 +1,46 @@
+; 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 \
+; RUN: | not grep load
+
+@A = global i32 7
+@B = global i32 8
+
+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
+}
+
+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()
+
+define i32 @test3() {
+	%X = alloca i32
+	store i32 7, i32* %X
+	call void @external()
+	%V = load i32* %X
+	ret i32 %V
+}
+