On 09/20/2012 07:42 PM, H.J. Lu wrote:
> On Fri, Aug 3, 2012 at 5:05 AM, Bernd Schmidt <ber...@codesourcery.com> wrote:
>> This patch allows us to change
>>
>> rn++
>> rm=[rn]
>>
>> into
>>
>> rm=[rn + 4]
>> rn++
>>
> This caused:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54645
The jury is still out on that, but it did cause PR54643. This seems to
be some kind of interaction with the new SCHED_PRESSURE_MODEL code. For
now it seems best to just disable the new optimization if scheduling for
pressure. It will still trigger during sched2.
I've bootstrapped the following on x86_64-linux and verified that the
arm build gets further (it now fails in libbacktrace). Committed.
Bernd
Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog (revision 191592)
+++ gcc/ChangeLog (working copy)
@@ -1,3 +1,9 @@
+2012-09-20 Bernd Schmidt <ber...@codesourcery.com>
+
+ PR bootstrap/54643
+ * haifa-sched.c (schedule_block): Skip find_modifiable_mems if using
+ SCHED_PRESSURE_MODEL.
+
2012-09-20 Joern Rennecke <joern.renne...@embecosm.com>
* rtlanal.c (dead_or_set_regno_p): Fix COND_EXEC handling.
Index: gcc/haifa-sched.c
===================================================================
--- gcc/haifa-sched.c (revision 191582)
+++ gcc/haifa-sched.c (working copy)
@@ -5854,7 +5854,8 @@ schedule_block (basic_block *target_bb)
rtx head = NEXT_INSN (prev_head);
rtx tail = PREV_INSN (next_tail);
- if ((current_sched_info->flags & DONT_BREAK_DEPENDENCIES) == 0)
+ if ((current_sched_info->flags & DONT_BREAK_DEPENDENCIES) == 0
+ && sched_pressure != SCHED_PRESSURE_MODEL)
find_modifiable_mems (head, tail);
/* We used to have code to avoid getting parameters moved from hard
