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Re: [RFH] - Less than optimal code compiling 252.eon -O2 for x86
On Jun 27, 2005, at 2:50 PM, Fariborz Jahanian wrote:
On Jun 27, 2005, at 12:56 PM, Richard Henderson wrote:
Hmm. I would suspect this is obsolete now. We'll have forced
everything into "registers" (or something equivalent that we
can work with) during tree optimization. Any CSEs that can be
made should have been made.
I will do sanity check followed by SPEC runs (x86 and ppc darwin)
and see if behavior changes by obsoleting -fforce-mem in -O2 (or
higher).
Bootstrapped and dejagnu tested on apple-x86-darwin and apple-ppc-
darwin.
We also observed that on ppc, SPEC did not show any performance
change either way. On apple-x86-darwin 252.eon improved by 7% as
expected, with no noticeable change in other benchmarks. One caveat
to all these is that this may expose optimization bugs which were
previously hidden by inclusion of -fforce-mem.
OK for check-in?
- fariborz
ChangeLog:
2005-06-30 Fariborz Jahanian <fjahanian@apple.com>
* opts.c (decode_options): Don't set -fforce-mem with -O2 and
more.
Index: opts.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/opts.c,v
retrieving revision 1.114
diff -c -p -r1.114 opts.c
*** opts.c 24 Jun 2005 03:09:45 -0000 1.114
--- opts.c 30 Jun 2005 15:55:15 -0000
*************** decode_options (unsigned int argc, const
*** 559,565 ****
flag_rerun_cse_after_loop = 1;
flag_rerun_loop_opt = 1;
flag_caller_saves = 1;
- flag_force_mem = 1;
flag_peephole2 = 1;
#ifdef INSN_SCHEDULING
flag_schedule_insns = 1;
--- 559,564 ----
- Thanks, fariborz
r~