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From: Joseph Myers <joseph@codesourcery.com>
To: Patrick McGehearty <patrick.mcgehearty@oracle.com>
Cc: <libc-alpha@sourceware.org>
Subject: Re: [PATCH] improves exp() and expf() performance on Sparc.
Date: Fri, 01 Sep 2017 23:14:00 -0000	[thread overview]
Message-ID: <alpine.DEB.2.20.1709012305290.26585@digraph.polyomino.org.uk> (raw)
In-Reply-To: <1504306749-46787-1-git-send-email-patrick.mcgehearty@oracle.com>

You're defining ifuncs for exp and expf (rather than __ieee754_exp, 
__exp_finite etc. as on x86_64).  But you're not doing anything to stop 
the w_exp_compat / w_expf_compat wrappers from being built that also 
define exp and expf, so I don't see how that can work without ending up 
with multiple definitions of exp and expf; I'd expect you to need to 
override the wrappers with empty files in such a case of a function 
implementation with all the error handling integrated.

I'm also concerned that you have local matherr handling which is not 
compatible with all the cases in __kernel_standard (which are not well 
tested).  If you need to have your own integrated error handling for 
performance reasons, matherr handling should be bug-compatible with the 
existing code, for both overflow and underflow.  (Or define a new symbol 
version, make the existing exp and expf into compat symbols for SPARC and 
then your new version only needs to handle errno setting, not matherr.)

-- 
Joseph S. Myers
joseph@codesourcery.com

  reply	other threads:[~2017-09-01 23:14 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-01 22:59 Patrick McGehearty
2017-09-01 23:14 ` Joseph Myers [this message]
2017-09-06 20:34   ` Patrick McGehearty
2017-09-06 21:01     ` Joseph Myers
2017-09-07 20:42       ` Patrick McGehearty
2017-09-07 21:05         ` Joseph Myers
2017-09-07 23:53           ` Patrick McGehearty
2017-09-04 11:43 ` Szabolcs Nagy
2017-09-06 20:31   ` Patrick McGehearty
2017-09-11 18:50 Wilco Dijkstra

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