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From: Christophe Lyon <christophe.lyon@linaro.org>
To: Kyrill Tkachov <kyrylo.tkachov@foss.arm.com>
Cc: Bernd Edlinger <bernd.edlinger@hotmail.de>,
	Wilco Dijkstra <Wilco.Dijkstra@arm.com>,
		Ramana Radhakrishnan <ramana.gcc@googlemail.com>,
	GCC Patches <gcc-patches@gcc.gnu.org>,
		Richard Earnshaw <Richard.Earnshaw@arm.com>, nd <nd@arm.com>
Subject: Re: [PING**2] [PATCH, ARM] Further improve stack usage on sha512 (PR 77308)
Date: Tue, 05 Sep 2017 18:20:00 -0000	[thread overview]
Message-ID: <CAKdteOa1hs3YCys1MwR_25nd-Q20Ld=cYPZehvLmaK4umMer6Q@mail.gmail.com> (raw)
In-Reply-To: <59AEE480.5070909@foss.arm.com>

On 5 September 2017 at 19:53, Kyrill  Tkachov
<kyrylo.tkachov@foss.arm.com> wrote:
>
> On 05/09/17 18:48, Bernd Edlinger wrote:
>>
>> On 09/05/17 17:02, Wilco Dijkstra wrote:
>>>
>>> Bernd Edlinger wrote:
>>>
>>>> Combine creates an invalid insn out of these two insns:
>>>
>>> Yes it looks like a latent bug. We need to use
>>> arm_general_register_operand
>>> as arm_adddi3/subdi3 only allow integer registers. You don't need a new
>>> predicate
>>> s_register_operand_nv. Also I'd prefer something like
>>> arm_general_adddi_operand.
>>>
>> Thanks, attached is a patch following your suggestion.
>>
>>> +  "TARGET_32BIT && ((!TARGET_NEON && !TARGET_IWMMXT) ||
>>> reload_completed)"
>>>
>>> The split condition for adddi3 now looks more accurate indeed, although
>>> we could
>>> remove the !TARGET_NEON from the split condition as this is always true
>>> given
>>> arm_adddi3 uses "TARGET_32BIT && !TARGET_NEON".
>>>
>> No, the split condition does not begin with "&& TARGET_32BIT...".
>> Therefore the split is enabled in TARGET_NEON after reload_completed.
>> And it is invoked from adddi3_neon for all alternatives without vfp
>> registers:
>>
>>     switch (which_alternative)
>>       {
>>       case 0: /* fall through */
>>       case 3: return "vadd.i64\t%P0, %P1, %P2";
>>       case 1: return "#";
>>       case 2: return "#";
>>       case 4: return "#";
>>       case 5: return "#";
>>       case 6: return "#";
>>
>>
>>
>>> Also there are more cases, a quick grep suggests *anddi_notdi_di has the
>>> same issue.
>>>
>> Yes, that pattern can be cleaned up in a follow-up patch.
>> Note this splitter is invoked from bicdi3_neon as well.
>> However I think anddi_notdi_di should be safe as long as it is enabled
>> after reload_completed (which is probably a bug).
>>
>
> Thanks, that's what I had in mind in my other reply.
> This is ok if testing comes back ok.
>

I've submitted the patch for testing, I'll let you know about the results.

Christophe

> Kyrill
>
>
>> Bernd.
>>
>>> Wilco
>>>
>

  reply	other threads:[~2017-09-05 18:20 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-06 14:18 Bernd Edlinger
2016-11-25 11:30 ` Ramana Radhakrishnan
2016-11-28 19:42   ` Bernd Edlinger
     [not found]     ` <VI1PR0802MB2621FFBFA3252B40E5978C9F838D0@VI1PR0802MB2621.eurprd08.prod.outlook.com>
2016-11-29 21:37       ` Bernd Edlinger
     [not found]         ` <AM5PR0802MB261038521472515DDE3E58DA838D0@AM5PR0802MB2610.eurprd08.prod.outlook.com>
2016-11-30 12:01           ` Wilco Dijkstra
2016-11-30 17:01             ` Bernd Edlinger
2016-12-08 19:50               ` Bernd Edlinger
2017-01-11 16:55                 ` Richard Earnshaw (lists)
2017-01-11 17:19                   ` Bernd Edlinger
2017-04-29 19:17     ` [PING**2] " Bernd Edlinger
2017-05-12 16:51       ` [PING**3] " Bernd Edlinger
2017-06-01 16:01         ` [PING**4] " Bernd Edlinger
     [not found]         ` <bd5e03b1-860f-dd16-2030-9ce0f9a94c7c@hotmail.de>
2017-06-14 12:35           ` [PING**5] " Bernd Edlinger
     [not found]           ` <9a0fbb5d-9909-ef4d-6871-0cb4f7971bbb@hotmail.de>
2017-07-05 18:14             ` [PING**6] " Bernd Edlinger
2017-09-04 14:52       ` [PING**2] " Kyrill Tkachov
2017-09-05  8:47         ` Christophe Lyon
2017-09-05 14:25           ` Bernd Edlinger
2017-09-05 15:02             ` Wilco Dijkstra
2017-09-05 17:48               ` Bernd Edlinger
2017-09-05 17:53                 ` Kyrill Tkachov
2017-09-05 18:20                   ` Christophe Lyon [this message]
2017-09-06  7:35                     ` Christophe Lyon
2017-09-05 21:28                 ` Wilco Dijkstra
2017-09-06  9:31                   ` Bernd Edlinger
2017-09-05 17:45             ` Kyrill Tkachov
2016-11-16 17:28 [PING] " Bernd Edlinger
2016-11-24 14:24 ` [PING**2] " Bernd Edlinger
2016-12-05 13:41   ` [PING] " Bernd Edlinger
2016-12-12  5:59     ` [PING**2] " Bernd Edlinger
2016-12-19  8:22       ` Bernd Edlinger

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