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Date: Thu, 12 Sep 2019 13:57:25 -0400
From: Rich Felker <dalias@...c.org>
To: info@...ile-stream.com
Cc: musl@...ts.openwall.com
Subject: Re: [PATCH] mips: add single-instruction math functions

On Wed, Sep 11, 2019 at 01:05:04PM +0300, info@...ile-stream.com wrote:
> 
> non-commit text:
> gcc puts annoying nop into the delay slot for these functions, e.g.:
> 	abs.d	$f0,$f12
> 	jr	$ra
> 	 nop
> is there any way to get rid of this without using pure .S?
> 
> 
> 
> SQRT.fmt exists on MIPS II+ (float), MIPS III+ (double).
> 
> ABS.fmt exists on MIPS I+ but only cores with ABS2008 flag in FCSR
> implement the required behaviour.

One other thing: can you confirm/cite that the mips sqrt instructions
are correctly-rounded? I would assume so but this needs checking since
there have been some low-end fpus that do things wrong (like early
pre-vfp ARM ones).

Rich

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