From: James Greenhalgh <james.greenhalgh@arm.com>
To: Christophe Lyon <christophe.lyon@linaro.org>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
nd@arm.com, Marcus Shawcroft <marcus.shawcroft@arm.com>,
Richard Earnshaw <richard.earnshaw@arm.com>
Subject: Re: [Patch AArch64 1/3] Enable CRC by default for armv8.1-a
Date: Thu, 07 Apr 2016 16:52:00 -0000 [thread overview]
Message-ID: <20160407165147.GA26236@arm.com> (raw)
In-Reply-To: <CAKdteOawbrV5LCrqVO1=UnAkHpDgL2mAg2JaK7M8coX3SKxOVA@mail.gmail.com>
On Thu, Apr 07, 2016 at 05:23:59PM +0200, Christophe Lyon wrote:
> On 6 April 2016 at 12:10, James Greenhalgh <james.greenhalgh@arm.com> wrote:
> >
> > Hi,
> >
> > This change reflects binutils support for CRC, where it is always enabled
> > for armv8.1-a.
> >
>
> Does v8.1 always enable CRC?
Yes. -march=armv8.1-a should always enable CRC. Unfortunately some
binutils versions do not honour this, which is why in the next patch we
must always put +crc out.
> If not, then don't you want to change the binutils default instead?
No, this patch is the correct thing to do - regadless of what binutils does,
GCC should enable access to the CRC intrinsics with -march=armv8.1-a, so we
want this patch.
Thanks,
James
> > ---
> > 2016-04-06 James Greenhalgh <james.greenhalgh@arm.com>
> >
> > * config/aarch64/aarch64.h (AARCH64_FL_FOR_ARCH8_1): Also add
> > AARCH64_FL_CRC.
> >
next prev parent reply other threads:[~2016-04-07 16:52 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-06 10:10 [Patch AArch64 0/3] Fix PR70133 James Greenhalgh
2016-04-06 10:10 ` [Patch AArch64 2/3] Rework the code to print extension strings (pr70133) James Greenhalgh
2016-04-06 10:10 ` [Patch AArch64 1/3] Enable CRC by default for armv8.1-a James Greenhalgh
2016-04-07 15:24 ` Christophe Lyon
2016-04-07 16:52 ` James Greenhalgh [this message]
2016-04-06 10:11 ` [Patch AArch64 3/3] Fix up for pr70133 James Greenhalgh
2016-04-07 12:23 ` Kyrill Tkachov
2016-04-11 9:22 ` James Greenhalgh
2016-04-11 9:58 ` [Patch AArch64 0/3] Fix PR70133 Richard Earnshaw (lists)
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