Linux SNPS ARC Archive on lore.kernel.org
 help / color / Atom feed
From: Vineet Gupta <Vineet.Gupta1@synopsys.com>
To: Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
	Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc: "linux-snps-arc@lists.infradead.org"
	<linux-snps-arc@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/4] ARC: allow to override default mcpu compiler flag
Date: Tue, 16 Jun 2020 22:12:27 +0000
Message-ID: <f3f54ba2-c050-83a2-ea93-dc147fd4bcfe@synopsys.com> (raw)
In-Reply-To: <MWHPR1201MB0046338E4B38598FFB5DBCB9A1860@MWHPR1201MB0046.namprd12.prod.outlook.com>

On 6/5/20 3:47 AM, Alexey Brodkin wrote:
> Hi Eugeniy,
> 
> A couple of minor notes below.
> 
>> -----Original Message-----
>> From: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
>> Sent: Thursday, June 4, 2020 8:39 PM
>> To: linux-snps-arc@lists.infradead.org; Vineet Gupta <vgupta@synopsys.com>
>> Cc: linux-kernel@vger.kernel.org; Alexey Brodkin <abrodkin@synopsys.com>; Eugeniy Paltsev
>> <paltsev@synopsys.com>
>> Subject: [PATCH v2 1/4] ARC: allow to override default mcpu compiler flag
>>
>> Kernel builds set their own default -mcpu for a given ISA build.
> 
> We used to use a default "-mcpu" per ARC ISA version (one for ARCompact
> and one for ARCv2).
> 
>> But that gets in the way of "custom" -mcpu flags from propagating
>> into kernel build.
> 
> But with more versions of CPUs & SoCs becoming available we want to
> be able to fine-tune generated code more precise.
> 
>> This will also be used in next patches for HSDK-4xD board support which
>> uses a different -mcpu to effect dual issue scheduling.
> 
> "...for utilization of the new CPU's dual-issue capabilities"?
> 
>> +++ b/arch/arc/Makefile
>> @@ -10,8 +10,25 @@ CROSS_COMPILE := $(call cc-cross-prefix, arc-linux- arceb-linux-)
>>  endif
>>
>>  cflags-y	+= -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
>> -cflags-$(CONFIG_ISA_ARCOMPACT)	+= -mA7
>> -cflags-$(CONFIG_ISA_ARCV2)	+= -mcpu=hs38
>> +
>> +tune-mcpu-def-$(CONFIG_ISA_ARCOMPACT)	:= -mA7
> 
> I'd suggest to either swap "-mA7" which is being obsoleted with "-mcpu=arc700"
> right here or as a separate change, otherwise we may soon get ATC700 builds
> broken with newer compilers.

FWIW I've added a modified variant of this patch to for-curr as we need it for
ongoing ARC64 port as well.

-Vineet
_______________________________________________
linux-snps-arc mailing list
linux-snps-arc@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-snps-arc

  reply index

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-04 17:39 [PATCH v2 0/4] ARC: [plat-hsdk-4xd] initial port for HSDK-4xD board Eugeniy Paltsev
2020-06-04 17:39 ` [PATCH v2 1/4] ARC: allow to override default mcpu compiler flag Eugeniy Paltsev
2020-06-04 18:27   ` Vineet Gupta
2020-06-05 10:47   ` Alexey Brodkin
2020-06-16 22:12     ` Vineet Gupta [this message]
2020-06-04 17:39 ` [PATCH v2 2/4] ARC: ARCv2: support loop buffer (LPB) disabling Eugeniy Paltsev
2020-06-18 19:50   ` Eugeniy Paltsev
2020-06-18 20:00     ` Vineet Gupta
2020-06-04 17:39 ` [PATCH v2 3/4] ARC: [plat-hsdk-4xd] initial port for HSDK-4xD board Eugeniy Paltsev
2020-06-04 22:02   ` Rob Herring
2020-06-04 17:39 ` [PATCH v2 4/4] ARC: [plat-hsdk*] document HSDK-4xD board/SoC bindings Eugeniy Paltsev
2020-06-04 20:00 ` [PATCH v2 0/4] ARC: [plat-hsdk-4xd] initial port for HSDK-4xD board Vineet Gupta

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=f3f54ba2-c050-83a2-ea93-dc147fd4bcfe@synopsys.com \
    --to=vineet.gupta1@synopsys.com \
    --cc=Alexey.Brodkin@synopsys.com \
    --cc=Eugeniy.Paltsev@synopsys.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-snps-arc@lists.infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux SNPS ARC Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-snps-arc/0 linux-snps-arc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-snps-arc linux-snps-arc/ https://lore.kernel.org/linux-snps-arc \
		linux-snps-arc@lists.infradead.org
	public-inbox-index linux-snps-arc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-snps-arc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git