On Wed, Nov 28, 2012 at 10:52:17AM +0100, Eric Botcazou wrote:
> No, I don't think that's the problem. The above messages are admittedly a
> bit
> terse, they should say:
>
> JUMP-BYPASS: Proved reg 59 in jump_insn 15 equals constant (const_int 3 [0x3])
> when BB 4 is entered from BB 9. Redirect edge 9->4 to 5.
>
> so you can have different constants for BB 3 and BB 9. The patch to tweak
> the
> dump messages along these lines is pre-approved.
Ouch. Okay, I'll post a separate patch for improving the message.
> The ICE in merge_latch_edges means that the loop structure and the CFG aren't
> in sync anymore. Does the cprop pass modify the former without declaring it?
I admit I'm not sure what to look at, maybe cprop should have in
properties_destroyed PROP_loops? Well, then we need to remove one
assert in loop-init.c. So something like:
--- gcc/cprop.c.mp 2012-11-28 16:55:03.520375191 +0100
+++ gcc/cprop.c 2012-11-28 16:55:35.992246623 +0100
@@ -1927,7 +1927,7 @@ struct rtl_opt_pass pass_rtl_cprop =
TV_CPROP, /* tv_id */
PROP_cfglayout, /* properties_required */
0, /* properties_provided */
- 0, /* properties_destroyed */
+ PROP_loops, /* properties_destroyed */
0, /* todo_flags_start */
TODO_df_finish | TODO_verify_rtl_sharing |
TODO_verify_flow | TODO_ggc_collect /* todo_flags_finish */
--- gcc/loop-init.c.mp 2012-11-28 16:55:08.924398879 +0100
+++ gcc/loop-init.c 2012-11-28 16:55:17.684437276 +0100
@@ -54,8 +54,6 @@ loop_optimizer_init (unsigned flags)
}
else
{
- gcc_assert (cfun->curr_properties & PROP_loops);
-
/* Ensure that the dominators are computed, like flow_loops_find does.
*/
calculate_dominance_info (CDI_DOMINATORS);
This quashes the ICE. I've regtested it, it caused one
regression though:
FAIL: gcc.dg/unroll_5.c scan-rtl-dump-times loop2_unroll "realistic
bound: 2999999" 1
But there probably is something else.
Thanks for the review,
Marek
