1 files changed, 15 insertions, 0 deletions
diff --git a/test/FrontendC/2008-01-25-ByValReadNone.c b/test/FrontendC/2008-01-25-ByValReadNone.c
new file mode 100644
index 0000000000..8ec60525af
--- /dev/null
+++ b/test/FrontendC/2008-01-25-ByValReadNone.c
@@ -0,0 +1,15 @@
+// RUN: %llvmgcc -O3 -S -o - -emit-llvm %s | not grep readonly
+// RUN: %llvmgcc -O3 -S -o - -emit-llvm %s | not grep readnone
+
+
+// The struct being passed byval means that we cannot mark the
+// function readnone.  Readnone would allow stores to the arg to
+// be deleted in the caller.  We also don't allow readonly since
+// the callee might write to the byval parameter.  The inliner
+// would have to assume the worse and introduce an explicit
+// temporary when inlining such a function, which is costly for
+// the common case in which the byval argument is not written.
+struct S { int A[1000]; };
+int __attribute__ ((const)) f(struct S x) { return x.A[0]; }
+int g(struct S x) __attribute__ ((pure));
+int h(struct S x) { return g(x); }