From: Andreas Schwab <schwab@suse.de>
To: Petr Tesarik <ptesarik@suse.cz>
Cc: gcc@gcc.gnu.org
Subject: Re: Branch instructions that depend on target distance
Date: Mon, 24 Feb 2020 11:51:00 -0000 [thread overview]
Message-ID: <mvmv9nww6dd.fsf@suse.de> (raw)
In-Reply-To: <20200224124149.08bd18ac@ezekiel.suse.cz> (Petr Tesarik's message of "Mon, 24 Feb 2020 12:41:49 +0100")
On Feb 24 2020, Petr Tesarik wrote:
> On Mon, 24 Feb 2020 12:29:40 +0100
> Andreas Schwab <schwab@suse.de> wrote:
>
>> On Feb 24 2020, Petr Tesarik wrote:
>>
>> > This works great ... until there's some inline asm() statement, for
>> > which gcc cannot keep track of the length attribute, so it is probably
>> > taken as zero.
>>
>> GCC computes it by counting the number of asm insns. You can use
>> ADJUST_INSN_LENGTH to adjust this as needed.
>
> Hmm, that's interesting, but does it work for inline asm() statements?
Yes, for a suitable definition of work.
> The argument is essentially a free-form string (with some
> substitution), and the compiler cannot know how many bytes they occupy.
That's why ADJUST_INSN_LENGTH can adjust it.
Andreas.
--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."
next prev parent reply other threads:[~2020-02-24 11:51 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-24 11:05 Petr Tesarik
2020-02-24 11:14 ` Jozef Lawrynowicz
2020-02-24 11:36 ` Petr Tesarik
2020-02-24 15:12 ` Jeff Law
2020-02-24 11:29 ` Andreas Schwab
2020-02-24 11:41 ` Petr Tesarik
2020-02-24 11:51 ` Andreas Schwab [this message]
2020-02-24 12:03 ` Alexander Monakov
2020-02-24 12:24 ` Julian Brown
2020-02-24 12:32 ` Petr Tesarik
2020-02-24 11:43 ` Andrew Stubbs
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