[Inline] add tests to show attribute information loss; NFC

llvm-svn: 295209

1 files changed, 50 insertions, 0 deletions

diff --git a/llvm/test/Transforms/Inline/arg-attr-propagation.ll b/llvm/test/Transforms/Inline/arg-attr-propagation.ll
new file mode 100644
index 00000000000..3d18e8047e5
--- /dev/null
+++ b/llvm/test/Transforms/Inline/arg-attr-propagation.ll
@@ -0,0 +1,50 @@
+; RUN: opt -inline -S < %s | FileCheck %s
+
+; The callee guarantees that the pointer argument is nonnull and dereferenceable.
+; That information should transfer to the caller.
+
+define i32 @callee(i32* dereferenceable(32) %t1) {
+; CHECK-LABEL: @callee(i32* dereferenceable(32) %t1)
+; CHECK-NEXT:    [[T2:%.*]] = load i32, i32* %t1
+; CHECK-NEXT:    ret i32 [[T2]]
+;
+  %t2 = load i32, i32* %t1
+  ret i32 %t2
+}
+
+; FIXME: All dereferenceability information is lost.
+; The caller argument could be known nonnull and dereferenceable(32).
+
+define i32 @caller1(i32* %t1) {
+; CHECK-LABEL: @caller1(i32* %t1)
+; CHECK-NEXT:    [[T2_I:%.*]] = load i32, i32* %t1
+; CHECK-NEXT:    ret i32 [[T2_I]]
+;
+  %t2 = tail call i32 @callee(i32* dereferenceable(32) %t1)
+  ret i32 %t2
+}
+
+; The caller argument is nonnull, but that can be explicit.
+; The dereferenceable amount could be increased.
+
+define i32 @caller2(i32* dereferenceable(31) %t1) {
+; CHECK-LABEL: @caller2(i32* dereferenceable(31) %t1)
+; CHECK-NEXT:    [[T2_I:%.*]] = load i32, i32* %t1
+; CHECK-NEXT:    ret i32 [[T2_I]]
+;
+  %t2 = tail call i32 @callee(i32* dereferenceable(32) %t1)
+  ret i32 %t2
+}
+
+; The caller argument is nonnull, but that can be explicit.
+; Make sure that we don't propagate a smaller dereferenceable amount.
+
+define i32 @caller3(i32* dereferenceable(33) %t1) {
+; CHECK-LABEL: @caller3(i32* dereferenceable(33) %t1)
+; CHECK-NEXT:    [[T2_I:%.*]] = load i32, i32* %t1
+; CHECK-NEXT:    ret i32 [[T2_I]]
+;
+  %t2 = tail call i32 @callee(i32* dereferenceable(32) %t1)
+  ret i32 %t2
+}
+