Add an Intraprocedural form of BasicAliasAnalysis, which aims to

properly handles instructions and arguments defined in different
functions, or across recursive function iterations.

llvm-svn: 107109

1 files changed, 42 insertions, 0 deletions

diff --git a/llvm/test/Analysis/BasicAA/interprocedural.ll b/llvm/test/Analysis/BasicAA/interprocedural.ll
new file mode 100644
index 00000000000..2195716cdf8
--- /dev/null
+++ b/llvm/test/Analysis/BasicAA/interprocedural.ll
@@ -0,0 +1,42 @@
+; RUN: opt -interprocedural-basic-aa  -interprocedural-aa-eval -print-all-alias-modref-info -disable-output < %s |& FileCheck %s
+
+; The noalias attribute is not safe in an interprocedural context.
+; CHECK: MayAlias: i8* %p, i8* %q
+
+define void @t0(i8* noalias %p) {
+  store i8 0, i8* %p
+  ret void
+}
+define void @t1(i8* noalias %q) {
+  store i8 0, i8* %q
+  ret void
+}
+
+; An alloca can alias an argument in a different function.
+; CHECK: MayAlias: i32* %r, i32* %s
+
+define void @s0(i32* %r) {
+  store i32 0, i32* %r
+  ret void
+}
+
+define void @s1() {
+  %s = alloca i32, i32 10
+  store i32 0, i32* %s
+  call void @s0(i32* %s)
+  ret void
+}
+
+; An alloca can alias an argument in a recursive function.
+; CHECK: MayAlias: i64* %t, i64* %u
+; CHECK: MayAlias: i64* %u, i64* %v
+; CHECK: MayAlias: i64* %t, i64* %v
+
+define i64* @r0(i64* %u) {
+  %t = alloca i64, i32 10
+  %v = call i64* @r0(i64* %t)
+  store i64 0, i64* %t
+  store i64 0, i64* %u
+  store i64 0, i64* %v
+  ret i64* %t
+}