https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69888
--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Jakub Jelinek from comment #1)
> Untested fix.
Looks OK, but please introduce a temporary variable, something like:
--cut here--
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index a1c87ab..6457293 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -26152,20 +26152,23 @@ decide_alg (HOST_WIDE_INT count, HOST_WIDE_INT
expected_size,
|| !alg_usable_p (algs->unknown_size, memset, have_as)))
{
enum stringop_alg alg;
+ HOST_WIDE_INT new_size;
- /* If there aren't any usable algorithms, then recursing on
- smaller sizes isn't going to find anything. Just return the
- simple byte-at-a-time copy loop. */
- if (!any_alg_usable_p)
+ if (max <= 0)
+ max = 4096;
+ /* If there aren't any usable algorithms or if recursing with the
+ same arguments as before, then recursing on smaller sizes or
+ same size isn't going to find anything. Just return the simple
+ byte-at-a-time copy loop. */
+ new_size = max / 2;
+ if (!any_alg_usable_p || new_size == orig_expected_size)
{
/* Pick something reasonable. */
if (TARGET_INLINE_STRINGOPS_DYNAMICALLY)
*dynamic_check = 128;
return loop_1_byte;
}
- if (max <= 0)
- max = 4096;
- alg = decide_alg (count, max / 2, min_size, max_size, memset,
+ alg = decide_alg (count, new_size, min_size, max_size, memset,
zero_memset, have_as, dynamic_check, noalign);
gcc_assert (*dynamic_check == -1);
if (TARGET_INLINE_STRINGOPS_DYNAMICALLY)
--cut here--
