From: Richard Henderson <richard.henderson@linaro.org>
To: BALATON Zoltan <balaton@eik.bme.hu>
Cc: "Alex Bennée" <alex.bennee@linaro.org>,
"QEMU Developers" <qemu-devel@nongnu.org>,
Programmingkid <programmingkidx@gmail.com>,
"qemu-ppc@nongnu.org" <qemu-ppc@nongnu.org>,
"Howard Spoelstra" <hsp.cat7@gmail.com>,
"luigi burdo" <intermediadc@hotmail.com>,
"Dino Papararo" <skizzato73@msn.com>,
"Aleksandar Markovic" <aleksandar.m.mail@gmail.com>,
"David Gibson" <david@gibson.dropbear.id.au>
Subject: Re: [RFC PATCH v2] target/ppc: Enable hardfloat for PPC
Date: Mon, 2 Mar 2020 16:11:06 -0800 [thread overview]
Message-ID: <ffecedad-d695-ebef-d494-fce307631223@linaro.org> (raw)
In-Reply-To: <alpine.BSF.2.22.395.2003030002340.47473@zero.eik.bme.hu>
On 3/2/20 3:16 PM, BALATON Zoltan wrote:
>> (2) IEEE has a number of implementation choices for corner cases, and we need
>> to implement the target's choices, not the host's choices.
>
> But how is that related to inexact flag and float_round_nearest_even rounding
> mode which are the only two things can_use_fpu() function checks for?
float_round_nearest_even is the default rounding mode, and is what the host fpu
has been set for. In order to use hardfloat for a different rounding mode, we
would need to change the host fpu control register, which is slow.
Inexact is the only flag that we cannot compute easily from the inputs and
output. We check for NaN and Inf as inputs and outputs,
which is the clue that we may have to raise Invalid or Overflow.
r~
next prev parent reply other threads:[~2020-03-03 0:11 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 17:10 [RFC PATCH v2] target/ppc: Enable hardfloat for PPC BALATON Zoltan
2020-02-18 17:38 ` BALATON Zoltan
2020-02-19 2:27 ` Programmingkid
2020-02-19 15:35 ` BALATON Zoltan
2020-02-19 18:28 ` Howard Spoelstra
2020-02-19 19:28 ` BALATON Zoltan
2020-02-20 5:43 ` Howard Spoelstra
2020-02-25 3:07 ` Programmingkid
2020-02-25 12:09 ` BALATON Zoltan
2020-02-26 10:46 ` Programmingkid
2020-02-26 11:28 ` BALATON Zoltan
2020-02-26 13:00 ` R: " luigi burdo
2020-02-26 13:08 ` Dino Papararo
2020-02-26 14:28 ` Alex Bennée
2020-02-26 15:50 ` Aleksandar Markovic
2020-02-26 17:04 ` G 3
2020-02-26 17:27 ` Aleksandar Markovic
2020-02-26 18:14 ` R: " Dino Papararo
2020-02-26 18:51 ` Aleksandar Markovic
2020-02-27 2:43 ` Programmingkid
2020-02-27 7:16 ` Aleksandar Markovic
2020-02-27 11:54 ` BALATON Zoltan
2020-02-26 18:09 ` R: " Alex Bennée
2020-03-02 0:13 ` Programmingkid
2020-03-02 4:28 ` Richard Henderson
2020-03-02 11:42 ` BALATON Zoltan
2020-03-02 16:55 ` Richard Henderson
2020-03-02 23:16 ` BALATON Zoltan
2020-03-03 0:11 ` Richard Henderson [this message]
[not found] ` <CAKyx-3Pt2qLPXWQjBwrHn-nxR-9e++TioGp4cKFC3adMN3rtiw@mail.gmail.com>
2020-03-04 18:43 ` Fwd: " G 3
2020-03-05 19:25 ` Richard Henderson
2020-03-02 17:10 ` Alex Bennée
2020-03-02 23:01 ` BALATON Zoltan
2020-02-26 22:51 ` R: " BALATON Zoltan
2020-02-20 20:13 ` Richard Henderson
2020-02-21 16:04 ` BALATON Zoltan
2020-02-21 16:11 ` Peter Maydell
2020-02-21 16:51 ` Aleksandar Markovic
2020-02-21 18:04 ` BALATON Zoltan
2020-02-21 18:26 ` Peter Maydell
2020-02-21 19:52 ` BALATON Zoltan
2020-02-26 12:28 ` Alex Bennée
2020-02-26 13:07 ` BALATON Zoltan
2020-04-10 13:50 ` 罗勇刚(Yonggang Luo)
2020-04-10 18:04 ` BALATON Zoltan
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