[Bug rtl-optimization/11488] Pre-regalloc scheduling severely worsens performance

[pthaugen at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488

Pat Haugen  changed:

   What|Removed |Added

 Target|alphaev68-*-*, powerpc-*-*  |alphaev68-*-*

--- Comment #14 from Pat Haugen  ---
(In reply to Pat Haugen from comment #13)
> Fixed on powerpc.

So removing it from target list.

[Bug rtl-optimization/11488] Pre-regalloc scheduling severely worsens performance

[pthaugen at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488

--- Comment #13 from Pat Haugen  ---
Fixed on powerpc. Testcase times (at 8X original loop count to get measurable
times).

base: 4.436 sec
base + -fno-schedule-insns: 2.052 sec
base + patch: 1.815 sec

[Bug rtl-optimization/11488] Pre-regalloc scheduling severely worsens performance

[pthaugen at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488

--- Comment #12 from Pat Haugen  ---
Author: pthaugen
Date: Wed Dec 21 19:15:32 2016
New Revision: 243866

URL: https://gcc.gnu.org/viewcvs?rev=243866=gcc=rev
Log:
PR rtl-optimization/11488
* common/config/rs6000/rs6000-common.c
(rs6000_option_optimization_table): Enable -fsched-pressure.
* config/rs6000/rs6000.c (TARGET_COMPUTE_PRESSURE_CLASSES): Define
target hook.
(rs6000_option_override_internal): Set default -fsched-pressure
algorithm.
(rs6000_compute_pressure_classes): Implement target hook.


Modified:
trunk/gcc/ChangeLog
trunk/gcc/common/config/rs6000/rs6000-common.c
trunk/gcc/config/rs6000/rs6000.c

[Bug rtl-optimization/11488] Pre-regalloc scheduling severely worsens performance

[mattst88 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488

Matt Turner  changed:

   What|Removed |Added

 CC||mattst88 at gmail dot com

--- Comment #11 from Matt Turner  ---
(In reply to Steven Bosscher from comment #10)
> Someone should try with -fsched-pressure...

On alpha with gcc-5.3.0:

% gcc -O2 -mbwx idct3.c && time ./a.out 
./a.out  1.72s user 0.00s system 99% cpu 1.721 total

% gcc -O2 -fno-schedule-insns -mbwx idct3.c && time ./a.out 
./a.out  0.96s user 0.01s system 99% cpu 0.970 total

% gcc -O2 -fsched-pressure -mbwx idct3.c && time ./a.out 
./a.out  1.01s user 0.00s system 99% cpu 1.016 total

(-mbwx is needed, otherwise -fsched-pressure/-fno-schedule-insns doesn't show
any benefit)

So it looks like -fsched-pressure helps significantly, but not quite as much as
-fno-schedule-insns.

[Bug rtl-optimization/11488] Pre-regalloc scheduling severely worsens performance

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488

--- Comment #10 from Steven Bosscher steven at gcc dot gnu.org 2011-05-22 
15:02:03 UTC ---
Someone should try with -fsched-pressure...

[Bug rtl-optimization/11488] Pre-regalloc scheduling severely worsens performance

[pinskia at gcc dot gnu dot org]

--- Comment #9 from pinskia at gcc dot gnu dot org  2008-09-14 03:10 ---
IRA improves this but it is still worse at -O2 than -O1 and than -O2
-fno-schedule-insns (which is the best so far).


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488

[Bug rtl-optimization/11488] Pre-regalloc scheduling severely worsens performance

[pinskia at gcc dot gnu dot org]

--- Additional Comments From pinskia at gcc dot gnu dot org  2004-11-06 17:50 
---
New timings from the mainline for PPC:
[zhivago:~/src/localgccPRs] pinskia% ~/local/bin/gcc -O2 pr11488.c 
-fno-schedule-insns[zhivago:~/
src/localgccPRs] pinskia% time ./a.out1.300u 0.010s 0:01.34 97.7% 0+0k 0+0io 
0pf+0w[zhivago:~/
src/localgccPRs] pinskia% ~/local/bin/gcc -O2 pr11488.c 
[zhivago:~/src/localgccPRs] pinskia% time ./a.out
4.060u 0.020s 0:04.16 98.0% 0+0k 0+0io 0pf+0w

-- 
   What|Removed |Added

   Last reconfirmed|2004-03-01 06:08:10 |2004-11-06 17:50:18
   date||


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11488