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authorJakub Jelinek <jakub@redhat.com>2005-12-16 13:12:41 +0100
committerJakub Jelinek <jakub@gcc.gnu.org>2005-12-16 13:12:41 +0100
commita1615718f5f7eae8acb173637725808d02bb9c00 (patch)
treeac8e1c720ac8e73c2f5c6adefd286fbc5483c5be /gcc
parent0c8c236b7ac9f111048741b57339eee2e72a0a3e (diff)
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re PR rtl-optimization/24899 (loop.c miscompiles libgnomecanvas)
PR rtl-optimization/24899 * loop.c (strength_reduce): Don't reduce giv that is not always computable and where add_val or mult_val can trap. * gcc.c-torture/execute/20051215-1.c: New test. From-SVN: r108642
Diffstat (limited to 'gcc')
-rw-r--r--gcc/ChangeLog4
-rw-r--r--gcc/loop.c11
-rw-r--r--gcc/testsuite/ChangeLog5
-rw-r--r--gcc/testsuite/gcc.c-torture/execute/20051215-1.c28
4 files changed, 48 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ccebcd7..f5e91e6 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
2005-12-16 Jakub Jelinek <jakub@redhat.com>
+ PR rtl-optimization/24899
+ * loop.c (strength_reduce): Don't reduce giv that is not always
+ computable and where add_val or mult_val can trap.
+
* doc/invoke.texi (-fdump-tree-*): Remove note about C/C++ only.
2005-12-16 Nathan Sidwell <nathan@codesourcery.com>
diff --git a/gcc/loop.c b/gcc/loop.c
index 0de77be..4aa1ff9 100644
--- a/gcc/loop.c
+++ b/gcc/loop.c
@@ -6486,6 +6486,17 @@ strength_reduce (struct loop *loop, int flags)
v->ignore = 1;
bl->all_reduced = 0;
}
+ else if (!v->always_computable
+ && (may_trap_or_fault_p (v->add_val)
+ || may_trap_or_fault_p (v->mult_val)))
+ {
+ if (loop_dump_stream)
+ fprintf (loop_dump_stream,
+ "giv of insn %d: not always computable.\n",
+ INSN_UID (v->insn));
+ v->ignore = 1;
+ bl->all_reduced = 0;
+ }
else
{
/* Check that we can increment the reduced giv without a
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8c49896..075dd3b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2005-12-16 Jakub Jelinek <jakub@redhat.com>
+
+ PR rtl-optimization/24899
+ * gcc.c-torture/execute/20051215-1.c: New test.
+
2005-12-16 Andreas Krebbel <krebbel1@de.ibm.com>
PR 24823
diff --git a/gcc/testsuite/gcc.c-torture/execute/20051215-1.c b/gcc/testsuite/gcc.c-torture/execute/20051215-1.c
new file mode 100644
index 0000000..143a449
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/20051215-1.c
@@ -0,0 +1,28 @@
+/* PR rtl-optimization/24899 */
+
+extern void abort (void);
+
+__attribute__ ((noinline)) int
+foo (int x, int y, int *z)
+{
+ int a, b, c, d;
+
+ a = b = 0;
+ for (d = 0; d < y; d++)
+ {
+ if (z)
+ b = d * *z;
+ for (c = 0; c < x; c++)
+ a += b;
+ }
+
+ return a;
+}
+
+int
+main (void)
+{
+ if (foo (3, 2, 0) != 0)
+ abort ();
+ return 0;
+}