* Re: Don't enable -fprefetch-loop-arrays for TARGET_SOFTWARE_PREFETCHING_BENEFICIAL if -Os
@ 2015-04-10 6:35 Uros Bizjak
0 siblings, 0 replies; 2+ messages in thread
From: Uros Bizjak @ 2015-04-10 6:35 UTC (permalink / raw)
To: gcc-patches; +Cc: Joseph S. Myers
Hello!
> Testing an x86_64 toolchain configured for a processor with
> TARGET_SOFTWARE_PREFETCHING_BENEFICIAL produces failures
>
> FAIL: g++.dg/pr60518.C -std=gnu++98 (test for excess errors)
> FAIL: g++.dg/pr60518.C -std=gnu++11 (test for excess errors)
> FAIL: g++.dg/pr60518.C -std=gnu++14 (test for excess errors)
>
> where the failure is from the message "pr60518.C:1:0: warning:
> -fprefetch-loop-arrays is not supported with -Os".
>
> Given that lack of support, it seems appropriate for the back end not
> to enable this option in the -Os case; this patch implements that.
>
> Bootstrapped with no regressions on x86_64-unknown-linux-gnu; tested
> for a cross to x86_64-linux-gnu --with-arch=btver2, where those test
> failures duly disappear. OK to commit?
>
> 2015-04-09 Joseph Myers <joseph@codesourcery.com>
>
> * config/i386/i386.c (ix86_option_override_internal): Don't set
> -fprefetch-loop-arrays if optimizing for size.
OK.
Thanks,
Uros.
^ permalink raw reply [flat|nested] 2+ messages in thread
* Don't enable -fprefetch-loop-arrays for TARGET_SOFTWARE_PREFETCHING_BENEFICIAL if -Os
@ 2015-04-09 22:06 Joseph Myers
0 siblings, 0 replies; 2+ messages in thread
From: Joseph Myers @ 2015-04-09 22:06 UTC (permalink / raw)
To: gcc-patches
Testing an x86_64 toolchain configured for a processor with
TARGET_SOFTWARE_PREFETCHING_BENEFICIAL produces failures
FAIL: g++.dg/pr60518.C -std=gnu++98 (test for excess errors)
FAIL: g++.dg/pr60518.C -std=gnu++11 (test for excess errors)
FAIL: g++.dg/pr60518.C -std=gnu++14 (test for excess errors)
where the failure is from the message "pr60518.C:1:0: warning:
-fprefetch-loop-arrays is not supported with -Os".
Given that lack of support, it seems appropriate for the back end not
to enable this option in the -Os case; this patch implements that.
Bootstrapped with no regressions on x86_64-unknown-linux-gnu; tested
for a cross to x86_64-linux-gnu --with-arch=btver2, where those test
failures duly disappear. OK to commit?
2015-04-09 Joseph Myers <joseph@codesourcery.com>
* config/i386/i386.c (ix86_option_override_internal): Don't set
-fprefetch-loop-arrays if optimizing for size.
Index: gcc/config/i386/i386.c
===================================================================
--- gcc/config/i386/i386.c (revision 221936)
+++ gcc/config/i386/i386.c (working copy)
@@ -4168,6 +4168,7 @@ ix86_option_override_internal (bool main_args_p,
if (opts->x_flag_prefetch_loop_arrays < 0
&& HAVE_prefetch
&& (opts->x_optimize >= 3 || opts->x_flag_profile_use)
+ && !opts->x_optimize_size
&& TARGET_SOFTWARE_PREFETCHING_BENEFICIAL)
opts->x_flag_prefetch_loop_arrays = 1;
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 2+ messages in thread
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2015-04-10 6:35 Don't enable -fprefetch-loop-arrays for TARGET_SOFTWARE_PREFETCHING_BENEFICIAL if -Os Uros Bizjak
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2015-04-09 22:06 Joseph Myers
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