Hi!
On the following testcase, we ICE due to infinite recursion in decide_alg
- max is 0, and expected_size is the same (2048) in the second and following
recursive calls.
Fixed by avoiding recursing with the same arguments as before.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2016-02-22 Jakub Jelinek <ja...@redhat.com>
PR target/69888
* config/i386/i386.c (decide_alg): Ensure we don't recurse with
identical arguments. Formatting and spelling fixes.
* gcc.target/i386/pr69888.c: New test.
--- gcc/config/i386/i386.c.jj 2016-02-12 00:50:55.000000000 +0100
+++ gcc/config/i386/i386.c 2016-02-22 10:25:53.564338145 +0100
@@ -26032,11 +26032,12 @@ decide_alg (HOST_WIDE_INT count, HOST_WI
bool memset, bool zero_memset, bool have_as,
int *dynamic_check, bool *noalign)
{
- const struct stringop_algs * algs;
+ const struct stringop_algs *algs;
bool optimize_for_speed;
int max = 0;
const struct processor_costs *cost;
int i;
+ HOST_WIDE_INT orig_expected_size = expected_size;
bool any_alg_usable_p = false;
*noalign = false;
@@ -26066,7 +26067,7 @@ decide_alg (HOST_WIDE_INT count, HOST_WI
any_alg_usable_p |= usable;
if (candidate != libcall && candidate && usable)
- max = algs->size[i].max;
+ max = algs->size[i].max;
}
/* If expected size is not known but max size is small enough
@@ -26076,7 +26077,7 @@ decide_alg (HOST_WIDE_INT count, HOST_WI
&& expected_size == -1)
expected_size = min_size / 2 + max_size / 2;
- /* If user specified the algorithm, honnor it if possible. */
+ /* If user specified the algorithm, honor it if possible. */
if (ix86_stringop_alg != no_stringop
&& alg_usable_p (ix86_stringop_alg, memset, have_as))
return ix86_stringop_alg;
@@ -26152,20 +26153,20 @@ decide_alg (HOST_WIDE_INT count, HOST_WI
|| !alg_usable_p (algs->unknown_size, memset, have_as)))
{
enum stringop_alg alg;
+ HOST_WIDE_INT new_expected_size = (max > 0 ? max : 4096) / 2;
- /* 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 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. */
+ if (!any_alg_usable_p || orig_expected_size == new_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_expected_size, min_size, max_size, memset,
zero_memset, have_as, dynamic_check, noalign);
gcc_assert (*dynamic_check == -1);
if (TARGET_INLINE_STRINGOPS_DYNAMICALLY)
--- gcc/testsuite/gcc.target/i386/pr69888.c.jj 2016-02-22 10:31:52.529401396
+0100
+++ gcc/testsuite/gcc.target/i386/pr69888.c 2016-02-22 10:34:10.852502628
+0100
@@ -0,0 +1,10 @@
+/* PR target/69888 */
+/* { dg-do compile } */
+/* { dg-options "-minline-all-stringops
-mmemset-strategy=no_stringop:-1:noalign" } */
+/* { dg-additional-options "-march=geode" { target ia32 } } */
+
+void
+foo (char *p)
+{
+ __builtin_memset (p, 0, 32);
+}
Jakub
