From: Kyrill Tkachov <kyrylo.tkachov@arm.com>
To: Kugan <kugan.vivekanandarajah@linaro.org>,
"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Cc: Ramana Radhakrishnan <Ramana.Radhakrishnan@arm.com>,
Richard Earnshaw <Richard.Earnshaw@arm.com>
Subject: Re: [ARM][PR65768] Keep constants in register when expanding
Date: Wed, 15 Apr 2015 08:21:00 -0000 [thread overview]
Message-ID: <552E1F88.4000804@arm.com> (raw)
In-Reply-To: <552E17C7.80800@linaro.org>
Hi Kugan,
On 15/04/15 08:48, Kugan wrote:
> As mentioned in PR65768, ARM gcc generates suboptimal code for constant
> Uses in loop. Part of the reason is that ARM back-end is splitting
> constants during expansion of RTL, making it hard for the RTL
> optimization passes to optimize it. Zhenqiang posted a patch at
> https://gcc.gnu.org/ml/gcc-patches/2014-08/msg00325.html to fix this
>
> As mentioned in PR65768, I tried with few more test-cases and enhanced
> it. Regression tested on arm-none-linux-gnu and no new regressions. Is
> this OK for trunk?
Can you please post the code generated for the testcase
before and after the patch for the record?
Thanks,
Kyrill
>
> Thanks,
> Kugan
>
>
> gcc/ChangeLog:
>
> 2015-04-15 Kugan Vivekanandarajah <kuganv@linaro.org>
> Zhenqiang Chen <zhenqiang.chen@linaro.org>
>
> PR target/65768
> * config/arm/arm-protos.h (const_ok_for_split): New definition.
> * config/arm/arm.c (const_ok_for_split): New function.
> * config/arm/arm.md (subsi3, andsi3, iorsi3, xorsi3, movsi): Keep some
> large constants in register instead of splitting them.
>
> gcc/testsuite/ChangeLog:
>
> 2015-04-15 Kugan Vivekanandarajah <kuganv@linaro.org>
> Zhenqiang Chen <zhenqiang.chen@linaro.org>
>
> PR target/65768
> * gcc.target/arm/maskdata.c: New test.
next prev parent reply other threads:[~2015-04-15 8:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-15 7:48 Kugan
2015-04-15 8:21 ` Kyrill Tkachov [this message]
2015-04-15 8:28 ` Kugan
2015-04-18 14:52 ` Richard Earnshaw
2015-04-26 23:08 ` Kugan
2015-05-14 5:47 ` Kugan
2015-05-14 9:26 ` Richard Earnshaw
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