[PATCH] Do not enable -fprefetch-loop-arrays with -fprofile-use (PR, gcov-profile/58250).

[PATCH] Do not enable -fprefetch-loop-arrays with -fprofile-use (PR, gcov-profile/58250).

[Martin Liška]

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Hi.

I've just grabbed patch a that was suggested in the PR (and IMHO makes sense).

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.

Ready to be installed?
Martin

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From e75e997f05d547017b3a962069fa4d1b024420cd Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Tue, 2 Aug 2016 09:21:22 +0200
Subject: [PATCH] Do not enable -fprefetch-loop-arrays with -fprofile-use (PR
 gcov-profile/58250).

gcc/ChangeLog:

2016-08-02  Martin Liska  <mliska@suse.cz>

	* config/i386/i386.c (ix86_option_override_internal):
	Do not enable -fprefetch-loop-arrays with -fprofile-use.
---
 gcc/config/i386/i386.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7c8bb17..91cea25 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -5847,7 +5847,7 @@ ix86_option_override_internal (bool main_args_p,
   /* Enable sw prefetching at -O3 for CPUS that prefetching is helpful.  */
   if (opts->x_flag_prefetch_loop_arrays < 0
       && HAVE_prefetch
-      && (opts->x_optimize >= 3 || opts->x_flag_profile_use)
+      && opts->x_optimize >= 3
       && !opts->x_optimize_size
       && TARGET_SOFTWARE_PREFETCHING_BENEFICIAL)
     opts->x_flag_prefetch_loop_arrays = 1;
-- 
2.9.2

Re: [PATCH] Do not enable -fprefetch-loop-arrays with -fprofile-use (PR, gcov-profile/58250).

[Richard Biener]

On Wed, Aug 3, 2016 at 11:54 AM, Martin Liška <mliska@suse.cz> wrote:
> Hi.
>
> I've just grabbed patch a that was suggested in the PR (and IMHO makes sense).
>
> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
>
> Ready to be installed?

Err, but what was suggested, not enable it with -Os is already done - you
disable it unconditionally?

Richard.

> Martin

Re: [PATCH] Do not enable -fprefetch-loop-arrays with -fprofile-use (PR, gcov-profile/58250).

[Martin Liška]

On 08/03/2016 03:28 PM, Richard Biener wrote:
> On Wed, Aug 3, 2016 at 11:54 AM, Martin Liška <mliska@suse.cz> wrote:
>> Hi.
>>
>> I've just grabbed patch a that was suggested in the PR (and IMHO makes sense).
>>
>> Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.
>>
>> Ready to be installed?
> 
> Err, but what was suggested, not enable it with -Os is already done - you
> disable it unconditionally?

Sorry, I was wrong ;) Looks the bug is fixed since r222033, where following hunk was added:

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 110ec4a..b442da9 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -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;

I'm going to close the PR.

Martin

> 
> Richard.
> 
>> Martin