This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] Fix loop pattern distribution ICE (PR tree-optimization/54321)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Mon, 20 Aug 2012 08:27:28 +0200
- Subject: [PATCH] Fix loop pattern distribution ICE (PR tree-optimization/54321)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
The middle-end argument of memset is signed (int), so simplify_builtin_call
correctly checks host_integerp (val2, 0), but later on used tree_low_cst
(val2, 1), so for negative values it would ICE. Fixed thusly, the memset
is supposed to cast the int to unsigned char internally anyway.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2012-08-20 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/54321
* tree-ssa-forwprop.c (simplify_builtin_call): Pass 0 instead of 1
as second argument to tree_low_cst call on val2.
* gcc.c-torture/compile/pr54321.c: New test.
--- gcc/tree-ssa-forwprop.c.jj 2012-08-14 08:45:00.000000000 +0200
+++ gcc/tree-ssa-forwprop.c 2012-08-20 08:11:06.247936035 +0200
@@ -1554,7 +1554,7 @@ simplify_builtin_call (gimple_stmt_itera
else
src_buf[0] = tree_low_cst (src1, 0);
memset (src_buf + tree_low_cst (diff, 1),
- tree_low_cst (val2, 1), tree_low_cst (len2, 1));
+ tree_low_cst (val2, 0), tree_low_cst (len2, 1));
src_buf[src_len] = '\0';
/* Neither builtin_strncpy_read_str nor builtin_memcpy_read_str
handle embedded '\0's. */
--- gcc/testsuite/gcc.c-torture/compile/pr54321.c.jj 2012-08-20 08:12:10.955630873 +0200
+++ gcc/testsuite/gcc.c-torture/compile/pr54321.c 2012-08-20 08:13:27.963398948 +0200
@@ -0,0 +1,12 @@
+/* PR tree-optimization/54321 */
+struct S { char s[0]; } *a;
+
+void
+foo (void)
+{
+ char *b = a->s;
+ int c = 0;
+ b[0] = 0;
+ while (++c < 9)
+ b[c] = 255;
+}
Jakub