From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <musl-return-15289-ml=inbox.vuxu.org@lists.openwall.com>
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org
X-Spam-Level: 
X-Spam-Status: No, score=-3.0 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3,
	RCVD_IN_MSPIKE_WL autolearn=ham autolearn_force=no version=3.4.2
Received: from mother.openwall.net (mother.openwall.net [195.42.179.200])
	by inbox.vuxu.org (OpenSMTPD) with SMTP id 67033ca2
	for <ml@inbox.vuxu.org>;
	Fri, 24 Jan 2020 14:45:27 +0000 (UTC)
Received: (qmail 3424 invoked by uid 550); 24 Jan 2020 14:45:25 -0000
Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm
Precedence: bulk
List-Post: <mailto:musl@lists.openwall.com>
List-Help: <mailto:musl-help@lists.openwall.com>
List-Unsubscribe: <mailto:musl-unsubscribe@lists.openwall.com>
List-Subscribe: <mailto:musl-subscribe@lists.openwall.com>
List-ID: <musl.lists.openwall.com>
Reply-To: musl@lists.openwall.com
Received: (qmail 3406 invoked from network); 24 Jan 2020 14:45:24 -0000
X-Authentication-Warning: key0.esi.com.au: damianm owned process doing -bs
Date: Sat, 25 Jan 2020 01:45:08 +1100 (AEDT)
From: Damian McGuckin <damianm@esi.com.au>
To: musl@lists.openwall.com
In-Reply-To: <20200124134402.GS30412@brightrain.aerifal.cx>
Message-ID: <alpine.LRH.2.02.2001250140330.29769@key0.esi.com.au>
References: <20200117164143.GB2020@voyager> <20200118011535.GD23985@port70.net> <alpine.LRH.2.02.2001181545420.21223@key0.esi.com.au> <20200118053759.GX30412@brightrain.aerifal.cx> <20200118094015.GE23985@port70.net> <alpine.LRH.2.02.2001240755500.28245@key0.esi.com.au>
 <20200124011122.GP30412@brightrain.aerifal.cx> <alpine.LRH.2.02.2001241227030.6298@key0.esi.com.au> <20200124045554.GR30412@brightrain.aerifal.cx> <alpine.LRH.2.02.2001241604050.13947@key0.esi.com.au> <20200124134402.GS30412@brightrain.aerifal.cx>
User-Agent: Alpine 2.02 (LRH 1266 2009-07-14)
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII
Subject: Re: [musl] Considering x86-64 fenv.s to C

On Fri, 24 Jan 2020, Rich Felker wrote:

>> 	static inline double get_fpscr_f(void)
>> 	{
>> 		double fpscr;
>>
>> 		__asm__ __volatile__ ("mffs %0" : "=d"(fpscr));
>> 		return fpscr;
>> 	}
>> 	static inline unsigned int get_csr(void)
>> 	{
>> 		return (unsigned int) (union {double f; long i;}) {get_fpscr_f()}.i;
>> 	}
>> 	static inline void set_fpscr_f(double fpscr)
>> 	{
>> 		__asm__ __volatile__ ("mtfsf 255, %0" : : "d"(fpscr));
>> 	}
>> 	static inline void set_csr(unsigned int fpscr)
>> 	{
>> 		set_fpscr_f((union {long i; double f;}) {(long) fpscr}.f);
>> 	}
>
> I would drop the _f functions; they're not useful separately

They are needed for fegetenv/fesetenv. The API defines

 	fenv_t

as a double, even though it is interpreted as a long when you have to use 
it.

Regards - Damian

Pacific Engineering Systems International, 277-279 Broadway, Glebe NSW 2037
Ph:+61-2-8571-0847 .. Fx:+61-2-9692-9623 | unsolicited email not wanted here
Views & opinions here are mine and not those of any past or present employer