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[PATCH] Fix up ix86_expand_set_or_movmem (PR target/61060)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Jan Hubicka <hubicka at ucw dot cz>, Uros Bizjak <ubizjak at gmail dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Mon, 12 May 2014 21:47:54 +0200
- Subject: [PATCH] Fix up ix86_expand_set_or_movmem (PR target/61060)
- Authentication-results: sourceware.org; auth=none
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
As discussed in the PR, ix86_expand_set_or_movmem assumes that count == 0
means !CONST_INT_P (count_exp), but that is not necessarily true with
-O0 -ftree-ter, when the middle-end doesn't immediately see the length
argument be integer_zerop, yet TER results in it being expanded as
const0_rtx.
There is nothing to set or move in that case, so this patch makes the
backend more tolerand just by returning true immediately.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2014-05-12 Jakub Jelinek <jakub@redhat.com>
PR target/61060
* config/i386/i386.c (ix86_expand_set_or_movmem): If count_exp
is const0_rtx, return immediately. Don't test count == 0 when
it is always true.
* gcc.dg/pr61060.c: New test.
--- gcc/config/i386/i386.c.jj 2014-05-11 22:21:28.000000000 +0200
+++ gcc/config/i386/i386.c 2014-05-12 10:59:18.940416162 +0200
@@ -24156,8 +24156,13 @@ ix86_expand_set_or_movmem (rtx dst, rtx
align = MEM_ALIGN (dst) / BITS_PER_UNIT;
if (CONST_INT_P (count_exp))
- min_size = max_size = probable_max_size = count = expected_size
- = INTVAL (count_exp);
+ {
+ min_size = max_size = probable_max_size = count = expected_size
+ = INTVAL (count_exp);
+ /* When COUNT is 0, there is nothing to do. */
+ if (!count)
+ return true;
+ }
else
{
if (min_size_exp)
@@ -24166,7 +24171,7 @@ ix86_expand_set_or_movmem (rtx dst, rtx
max_size = INTVAL (max_size_exp);
if (probable_max_size_exp)
probable_max_size = INTVAL (probable_max_size_exp);
- if (CONST_INT_P (expected_size_exp) && count == 0)
+ if (CONST_INT_P (expected_size_exp))
expected_size = INTVAL (expected_size_exp);
}
--- gcc/testsuite/gcc.dg/pr61060.c.jj 2014-05-12 11:03:10.797222337 +0200
+++ gcc/testsuite/gcc.dg/pr61060.c 2014-05-12 11:03:02.882263281 +0200
@@ -0,0 +1,19 @@
+/* PR target/61060 */
+/* { dg-do compile } */
+/* { dg-options "-O0 -ftree-ter" } */
+
+typedef __SIZE_TYPE__ size_t;
+
+extern inline __attribute__ ((gnu_inline, always_inline, artificial))
+void *memset (void *dest, int ch, size_t len)
+{
+ return __builtin_memset (dest, ch, len);
+}
+
+char buf[10];
+
+void
+foo (void)
+{
+ memset (buf, sizeof (buf), 0);
+}
Jakub