This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] Fix PR56466
- From: Marek Polacek <polacek at redhat dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Cc: Richard Biener <rguenther at suse dot de>
- Date: Wed, 27 Feb 2013 15:47:59 +0100
- Subject: [PATCH] Fix PR56466
This patch does two things: it fixes PR56466 by calling fix_loop_structure
in case we're changing a loop, and secondly, it makes verifiyng
loops in the unroller cheaper: there's no need to verify each loop,
we can do it once after all transformations (verify_loop_structure is
being called via fix_loop_structure).
Regtested/bootstrapped on x86_64-linux, ok for trunk?
2013-02-27 Marek Polacek <polacek@redhat.com>
PR rtl-optimization/56466
* loop-unroll.c (unroll_and_peel_loops): Call fix_loop_structure
if we're changing a loop.
(peel_loops_completely): Likewise.
* gcc.dg/pr56466.c: New test.
--- gcc/loop-unroll.c.mp 2013-02-27 11:13:01.915430193 +0100
+++ gcc/loop-unroll.c 2013-02-27 14:57:09.873168342 +0100
@@ -207,7 +207,7 @@ void
unroll_and_peel_loops (int flags)
{
struct loop *loop;
- bool check;
+ bool changed = false;
loop_iterator li;
/* First perform complete loop peeling (it is almost surely a win,
@@ -220,7 +220,6 @@ unroll_and_peel_loops (int flags)
/* Scan the loops, inner ones first. */
FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
{
- check = true;
/* And perform the appropriate transformations. */
switch (loop->lpt_decision.decision)
{
@@ -229,30 +228,33 @@ unroll_and_peel_loops (int flags)
gcc_unreachable ();
case LPT_PEEL_SIMPLE:
peel_loop_simple (loop);
+ changed |= true;
break;
case LPT_UNROLL_CONSTANT:
unroll_loop_constant_iterations (loop);
+ changed |= true;
break;
case LPT_UNROLL_RUNTIME:
unroll_loop_runtime_iterations (loop);
+ changed |= true;
break;
case LPT_UNROLL_STUPID:
unroll_loop_stupid (loop);
+ changed |= true;
break;
case LPT_NONE:
- check = false;
break;
default:
gcc_unreachable ();
}
- if (check)
- {
-#ifdef ENABLE_CHECKING
- verify_loop_structure ();
-#endif
- }
}
+ if (changed)
+ {
+ calculate_dominance_info (CDI_DOMINATORS);
+ fix_loop_structure (NULL);
+ }
+
iv_analysis_done ();
}
@@ -283,6 +285,7 @@ peel_loops_completely (int flags)
{
struct loop *loop;
loop_iterator li;
+ bool changed = false;
/* Scan the loops, the inner ones first. */
FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
@@ -306,11 +309,15 @@ peel_loops_completely (int flags)
{
report_unroll_peel (loop, locus);
peel_loop_completely (loop);
-#ifdef ENABLE_CHECKING
- verify_loop_structure ();
-#endif
+ changed = true;
}
}
+
+ if (changed)
+ {
+ calculate_dominance_info (CDI_DOMINATORS);
+ fix_loop_structure (NULL);
+ }
}
/* Decide whether unroll or peel loops (depending on FLAGS) and how much. */
--- gcc/testsuite/gcc.dg/pr56466.c.mp 2013-02-27 12:43:44.468886756 +0100
+++ gcc/testsuite/gcc.dg/pr56466.c 2013-02-27 12:46:36.385390735 +0100
@@ -0,0 +1,31 @@
+/* PR rtl-optimization/56466 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -w -funroll-loops" } */
+
+int a, b, c;
+
+void
+f (void)
+{
+ for (; b; b++)
+ {
+ if (0)
+ for (; b < 0; b++)
+ if (1 % 0)
+ {
+ while (1)
+ {
+ a = 0;
+ lbl1:
+ c++;
+ }
+ lbl2:
+ ;
+ }
+
+ goto lbl1;
+ }
+
+ a = 0;
+ goto lbl2;
+}
Marek