From: Richard Biener <rguenther@suse.de>
To: "Andre Vieira (lists)" <andre.simoesdiasvieira@arm.com>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
Richard Sandiford <richard.sandiford@arm.com>
Subject: Re: [AArch64] Enable generation of FRINTNZ instructions
Date: Fri, 12 Nov 2021 11:56:05 +0100 (CET) [thread overview]
Message-ID: <70s9nn94-452-5rrr-4458-q6n3qp563652@fhfr.qr> (raw)
In-Reply-To: <8225375c-eb9e-f9b3-6bcd-9fbccf2fc87b@arm.com>
On Thu, 11 Nov 2021, Andre Vieira (lists) wrote:
> Hi,
>
> This patch introduces two IFN's FTRUNC32 and FTRUNC64, the corresponding
> optabs and mappings. It also creates a backend pattern to implement them for
> aarch64 and a match.pd pattern to idiom recognize these.
> These IFN's (and optabs) represent a truncation towards zero, as if performed
> by first casting it to a signed integer of 32 or 64 bits and then back to the
> same floating point type/mode.
>
> The match.pd pattern choses to use these, when supported, regardless of
> trapping math, since these new patterns mimic the original behavior of
> truncating through an integer.
>
> I didn't think any of the existing IFN's represented these. I know it's a bit
> late in stage 1, but I thought this might be OK given it's only used by a
> single target and should have very little impact on anything else.
>
> Bootstrapped on aarch64-none-linux.
>
> OK for trunk?
On the RTL side ftrunc32/ftrunc64 would probably be better a conversion
optab (with two modes), so not
+OPTAB_D (ftrunc32_optab, "ftrunc$asi2")
+OPTAB_D (ftrunc64_optab, "ftrunc$adi2")
but
OPTAB_CD (ftrunc_shrt_optab, "ftrunc$a$I$b2")
or so? I know that gets somewhat awkward for the internal function,
but IMHO we shouldn't tie our hands because of that?
Richard.
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.md (ftrunc<mode><frintnz_mode>2): New
> pattern.
> * config/aarch64/iterators.md (FRINTZ): New iterator.
> * doc/md.texi: New entry for ftrunc pattern name.
> * internal-fn.def (FTRUNC32): New IFN.
> (FTRUNC64): Likewise.
> * match.pd: Add to the existing TRUNC pattern match.
> * optabs.def (OPTAB_D): New entries for ftrunc.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/merge_trunc1.c: Adapted to skip if frintNz
> instruction available.
> * lib/target-supports.exp: Added arm_v8_5a_frintnzx_ok target.
> * gcc.target/aarch64/frintnz.c: New test.
>
>
--
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Ivo Totev; HRB 36809 (AG Nuernberg)
next prev parent reply other threads:[~2021-11-12 10:56 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-11 17:51 Andre Vieira (lists)
2021-11-12 10:56 ` Richard Biener [this message]
2021-11-12 11:48 ` Andre Simoes Dias Vieira
2021-11-16 12:10 ` Richard Biener
2021-11-17 13:30 ` Andre Vieira (lists)
2021-11-17 15:38 ` Richard Sandiford
2021-11-18 11:05 ` Richard Biener
2021-11-22 11:38 ` Andre Vieira (lists)
2021-11-22 11:41 ` Richard Biener
2021-11-25 13:53 ` Andre Vieira (lists)
2021-12-07 11:29 ` Andre Vieira (lists)
2021-12-17 12:44 ` Richard Sandiford
2021-12-29 15:55 ` Andre Vieira (lists)
2021-12-29 16:54 ` Richard Sandiford
2022-01-03 12:18 ` Richard Biener
2022-01-10 14:09 ` Andre Vieira (lists)
2022-01-10 14:45 ` Richard Biener
2022-01-14 10:37 ` Richard Sandiford
2022-11-04 17:40 ` Andre Vieira (lists)
2022-11-07 11:05 ` Richard Biener
2022-11-07 14:19 ` Andre Vieira (lists)
2022-11-07 14:56 ` Richard Biener
2022-11-09 11:33 ` Andre Vieira (lists)
2022-11-15 18:24 ` Richard Sandiford
2022-11-16 12:25 ` Richard Biener
2021-11-29 11:17 ` Andre Vieira (lists)
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