This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: [Fortran, Patch] Memory sync after coarray image control statements and assignment

From: Matthew Wahab <matthew dot wahab at foss dot arm dot com>
To: Tobias Burnus <tobias dot burnus at physik dot fu-berlin dot de>, fortran at gcc dot gnu dot org, gcc-patches at gcc dot gnu dot org, Alessandro Fanfarillo <fanfarillo dot gcc at gmail dot com>
Date: Mon, 7 Dec 2015 14:09:22 +0000
Subject: Re: [Fortran, Patch] Memory sync after coarray image control statements and assignment
Authentication-results: sourceware.org; auth=none
References: <20151207100645 dot GA28286 at physik dot fu-berlin dot de>

On 07/12/15 10:06, Tobias Burnus wrote:

I wrote:

I wonder whether using

__asm__ __volatile__ ("":::"memory");

would be sufficient as it has a way lower overhead than
__sync_synchronize().


Namely, something like the attached patch.

Regarding the original patch submission: Is there a reason that you didn't
include the test case of Deepak from https://gcc.gnu.org/ml/fortran/2015-04/msg00062.html
It should work as -fcoarray=lib -lcaf_single "dg-do run" test.

Tobias

I don't know anything about Fortran or coarrays and I'm curious whether this affectsarchitectures with weak memory models. Is the barrier only needed to stop reorderingby the compiler or is does it also need to stop reordering by the hardware?


Matthew

Follow-Ups:
- Re: [Fortran, Patch] Memory sync after coarray image control statements and assignment
  - From: Tobias Burnus

References:
- Re: [Fortran, Patch] Memory sync after coarray image control statements and assignment
  - From: Tobias Burnus

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]