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From: "Bin.Cheng" <amker.cheng@gmail.com>
To: Kyrill Tkachov <kyrylo.tkachov@arm.com>
Cc: Bin Cheng <bin.cheng@arm.com>,
	"gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH ARM]Fix pr42172-1.c failure on pre armv7 processors
Date: Thu, 23 Apr 2015 08:53:00 -0000	[thread overview]
Message-ID: <CAHFci2_cxAad+5bOgu2tbmLbfFCTztpeTdHyPXMeWRFWLB=jhw@mail.gmail.com> (raw)
In-Reply-To: <5538AAF8.7060001@arm.com>

On Thu, Apr 23, 2015 at 4:19 PM, Kyrill Tkachov <kyrylo.tkachov@arm.com> wrote:
>
> On 22/04/15 09:42, Bin Cheng wrote:
>>
>> Hi,
>> Case pr42172-1.c failed on pre-armv7 processors because GCC actually
>> generates better code without ldr instruction.  This patch just refines
>> test
>> case by checking str instead of ldr, makes sure the case passes on all arm
>> processors.  In the end, we need to fix GCC combiner to generate optimal
>> code on armv7 processors too.  PR42172 is kept open for that purpose.
>>
>> This is obvious change, is it OK for branches too?
>
>
> For the record, for -mcpu=arm7tdmi we now generate:
> init_A:
>         mov     r3, #8
>         strb    r3, [r0]
>         bx
That's the point, it generates optimal code for pre-armv7 processors,
which is treated as failure now.

>
>
> Ok for trunk. Is this test failing on the branches too?
Well, at least for gcc-5-branch.

>
> Kyrill
>
>
>>
>> gcc/testsuite/ChangeLog
>> 2015-04-22  Bin Cheng  <bin.cheng@arm.com>
>>
>>         * gcc.target/arm/pr42172-1.c: Check str instead of ldr.
>>
>

  reply	other threads:[~2015-04-23  8:53 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-22  8:42 Bin Cheng
2015-04-23  8:19 ` Kyrill Tkachov
2015-04-23  8:53   ` Bin.Cheng [this message]
2015-04-23  9:04     ` Kyrill Tkachov

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