* builtins.c (fold_builtin_memory_op): Optimize memmove

	into memcpy if we can prove source and destination don't overlap.

	* gcc.dg/memmove-2.c: New test.
	* gcc.dg/memmove-3.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@145127 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 16 insertions, 0 deletions

diff --git a/gcc/testsuite/gcc.dg/memmove-2.c b/gcc/testsuite/gcc.dg/memmove-2.c
new file mode 100644
index 00000000000..9c691ef01c3
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/memmove-2.c
@@ -0,0 +1,16 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump-times "memmove" 0 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */
+
+char a[40];
+extern void bar (char *);
+
+void
+foo (void)
+{
+  char b[10];
+  __builtin_memmove (&a[0], &a[20], 20);
+  __builtin_memmove (&b[1], &a[25], 9);
+  bar (b);
+}