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[PATCH] Fix RTL sharing bug in loop unswitching (PR rtl-optimization/52092)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: Eric Botcazou <ebotcazou at adacore dot com>, Richard Guenther <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Thu, 2 Feb 2012 20:12:27 +0100
- Subject: [PATCH] Fix RTL sharing bug in loop unswitching (PR rtl-optimization/52092)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
It seems loop-iv.c happily creates shared RTL in lots of places,
loop-unroll.c solves that by unsharing everything it adds, this is
an attempt to do the same in unswitching to unshare everything iv_analyze
came up with.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2012-02-02 Jakub Jelinek <jakub@redhat.com>
PR rtl-optimization/52092
* loop-unswitch.c (may_unswitch_on): Call copy_rtx_if_shared
on get_iv_value result.
* gcc.c-torture/compile/pr52092.c: New test.
--- gcc/loop-unswitch.c.jj 2010-06-28 15:36:30.000000000 +0200
+++ gcc/loop-unswitch.c 2012-02-02 14:00:55.127749909 +0100
@@ -204,6 +204,7 @@ may_unswitch_on (basic_block bb, struct
return NULL_RTX;
op[i] = get_iv_value (&iv, const0_rtx);
+ op[i] = copy_rtx_if_shared (op[i]);
}
mode = GET_MODE (op[0]);
--- gcc/testsuite/gcc.c-torture/compile/pr52092.c.jj 2012-02-02 14:11:37.722031008 +0100
+++ gcc/testsuite/gcc.c-torture/compile/pr52092.c 2012-02-02 14:11:14.000000000 +0100
@@ -0,0 +1,25 @@
+/* PR rtl-optimization/52092 */
+
+int a, b, c, d, e, f, g;
+
+void
+foo (void)
+{
+ for (;;)
+ {
+ int *h = 0;
+ int i = 3;
+ int **j = &h;
+ if (e)
+ {
+ c = d || a;
+ g = c ? a : b;
+ if ((char) (i * g))
+ {
+ h = &f;
+ *h = 0;
+ }
+ **j = 0;
+ }
+ }
+}
Jakub