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[Patch] Do not rerun loop optimisation by default.
- To: gcc-patches at gcc dot gnu dot org
- Subject: [Patch] Do not rerun loop optimisation by default.
- From: Toon Moene <toon at moene dot indiv dot nluug dot nl>
- Date: Sat, 08 Sep 2001 21:31:23 +0200
- Organization: Moene Computational Physics, Maartensdijk, The Netherlands
Because of the work done by Richard Henderson on recognising all
{general} induction variables in loops, it should not be necessary
anymore to rerun loop optimisation.
The reason I invented this was that originally, loop optimisation didn't
recognise BIV+INVARIANT+CONSTANT as a GIV, something that arises
regularly from addressing [multi-rank] arrays in Fortran.
However, as I alluded to above, this is all history. So I propose to
drop rerunning loop optimisation by default (bootstrap'd, make dvi'd,
make -k check'd and installed on i686-pc-linux-gnu):
2001-09-08 Toon Moene <toon@moene.indiv.nluug.nl>
* toplev.c: Do not rerun loop optimisation by default for -On,
n >= 2.
*** toplev.c.orig Wed Sep 5 22:19:25 2001
--- toplev.c Sat Sep 8 16:16:57 2001
*************** toplev_main (argc, argv)
*** 4703,4707 ****
flag_strength_reduce = 1;
flag_rerun_cse_after_loop = 1;
- flag_rerun_loop_opt = 1;
flag_caller_saves = 1;
flag_force_mem = 1;
--- 4703,4706 ----
2001-09-08 Toon Moene <toon@moene.indiv.nluug.nl>
* f/g77.texi: Document that we do not rerun loop optimisation
by default.
*** f/g77.texi.orig Wed Jul 4 21:09:36 2001
--- f/g77.texi Sat Sep 8 13:52:41 2001
*************** by type. Explanations are in the follow
*** 970,974 ****
-funroll-loops -funroll-all-loops
-fno-move-all-movables -fno-reduce-all-givs
! -fno-rerun-loop-opt
@end smallexample
--- 970,974 ----
-funroll-loops -funroll-all-loops
-fno-move-all-movables -fno-reduce-all-givs
! -frerun-loop-opt
@end smallexample
*************** but possibly slower.
*** 2379,2385 ****
@cindex -fno-reduce-all-givs option
@cindex options, -fno-reduce-all-givs
! @item -fno-rerun-loop-opt
! @cindex -fno-rerun-loop-opt option
! @cindex options, -fno-rerun-loop-opt
@emph{Version info:}
These options are not supported by
--- 2379,2385 ----
@cindex -fno-reduce-all-givs option
@cindex options, -fno-reduce-all-givs
! @item -frerun-loop-opt
! @cindex -frerun-loop-opt option
! @cindex options, -frerun-loop-opt
@emph{Version info:}
These options are not supported by
Could someone with global privileges approve (or disapprove) this,
please ?
Thanks,
--
Toon Moene - mailto:toon@moene.indiv.nluug.nl - phoneto: +31 346 214290
Saturnushof 14, 3738 XG Maartensdijk, The Netherlands
Maintainer, GNU Fortran 77: http://gcc.gnu.org/onlinedocs/g77_news.html
Join GNU Fortran 95: http://g95.sourceforge.net/ (under construction)