Initial tests for DS alias analysis

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5481 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 55 insertions, 0 deletions

diff --git a/test/Analysis/DSGraph/gcsetest.ll b/test/Analysis/DSGraph/gcsetest.ll
new file mode 100644
index 0000000..d451ed5
--- /dev/null
+++ b/test/Analysis/DSGraph/gcsetest.ll
@@ -0,0 +1,55 @@
+; Test that GCSE uses ds-aa to do alias analysis, which is capable of 
+; disambiguating some cases.
+
+; RUN: if as < %s | opt -ds-aa -load-vn -gcse -instcombine -dce | dis | grep ELIM
+; RUN: then exit 1
+; RUN: else exit 0
+; RUN: fi
+
+%intpair = type {int*, int*}
+implementation
+
+%intpair *%alloc_pair() {
+	%Ap = malloc int
+	%Bp = malloc int
+ 	%C  = malloc {int*, int*}
+	%C1p = getelementptr {int*, int*}* %C, long 0, ubyte 0
+	store int* %Ap, int** %C1p
+	%C2p = getelementptr {int*, int*}* %C, long 0, ubyte 1
+	store int* %Bp, int** %C2p
+	ret %intpair* %C
+}
+
+int %test() {
+	%C = call %intpair* %alloc_pair()
+	%C1p = getelementptr %intpair* %C, long 0, ubyte 0
+	%C2p = getelementptr %intpair* %C, long 0, ubyte 1
+	%A = load int** %C1p
+	%B = load int** %C2p
+	%A1 = load int* %A
+
+	store int 123, int* %B  ; Store cannot alias %A
+
+	%A2 = load int* %A
+	%ELIM_x = sub int %A1, %A2
+	ret int %ELIM_x
+}
+
+int* %getp(%intpair* %P) {
+	%pp = getelementptr %intpair* %P, long 0, ubyte 0
+	%V = load int** %pp
+	ret int *%V
+}
+
+int %test2() {   ; Test context sensitivity
+	%C1 = call %intpair* %alloc_pair()
+	%C2 = call %intpair* %alloc_pair()
+	%P1 = call int* %getp(%intpair* %C1)
+	%P2 = call int* %getp(%intpair* %C2)
+	%X = load int* %P1
+	store int 7, int* %P2
+	%Y = load int* %P1
+	%ELIM_x = sub int %X, %Y
+	ret int %ELIM_x
+}
+