From: Sunil Pandey <skpgkp2@gmail.com>
To: Joseph Myers <joseph@codesourcery.com>
Cc: GNU C Library <libc-alpha@sourceware.org>, andrey.kolesov@intel.com
Subject: Re: [PATCH 5/6] x86-64: Add pow/powf to libmvec microbenchmark
Date: Wed, 10 Nov 2021 19:31:13 -0800 [thread overview]
Message-ID: <CAMAf5_dmzTV-FpNut29d19Cjx+d9Jbh1qgZQhtuuv3UjMX+2jw@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.22.394.2111102026010.118420@digraph.polyomino.org.uk>
On Wed, Nov 10, 2021 at 12:27 PM Joseph Myers <joseph@codesourcery.com>
wrote:
> On Tue, 9 Nov 2021, Sunil K Pandey via Libc-alpha wrote:
>
> > +# Random inputs in [a=0.01,b=100.00], [c=0.01,d=10.00]
>
> I think there should be a reasonable proportion of negative exponents,
> unless you have evidence that negative exponents are rarely used in
> practice. (The *first* argument of pow being negative is of use (produces
> finite results) in much more limited cases, so may well be much rarer.)
>
Negative exponents not used in the input file to avoid denormal
processing. Negative
exponent
may hit the underflow domain when pow(x, -y) produces denormals as results
or as intermediate
values. Both going to touch very slow special pow() path and invokes Intel
software assist for
denormals processing. All of this will distort the overall performance
result of the main path.
Also the base argument should be small so that it doesn’t produce denormals.
> --
> Joseph S. Myers
> joseph@codesourcery.com
>
next prev parent reply other threads:[~2021-11-11 3:31 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-10 3:07 [PATCH 0/6] Implement microbenchmark for libmvec Sunil K Pandey
2021-11-10 3:07 ` [PATCH 1/6] x86-64: Create microbenchmark infrastructure " Sunil K Pandey
2021-11-10 3:53 ` Noah Goldstein
2021-11-11 18:34 ` Sunil Pandey
2021-11-12 19:17 ` [PATCH v2 0/6] Implement microbenchmark " Sunil K Pandey
2021-11-12 19:17 ` [PATCH v2 1/6] x86-64: Create microbenchmark infrastructure " Sunil K Pandey
2021-11-12 21:02 ` Noah Goldstein
2021-11-12 22:49 ` Sunil Pandey
2021-11-13 19:47 ` H.J. Lu
2021-11-14 2:59 ` Sunil Pandey
2021-11-15 21:06 ` [PATCH v3 0/6] Implement microbenchmark " Sunil K Pandey
2021-11-15 21:06 ` [PATCH v3 1/6] x86-64: Create microbenchmark infrastructure " Sunil K Pandey
2021-11-16 17:21 ` H.J. Lu
2021-11-16 18:37 ` [PATCH] " Sunil K Pandey
2021-11-16 18:40 ` H.J. Lu
2021-11-15 21:06 ` [PATCH v3 2/6] x86-64: Add vector cos/cosf to libmvec microbenchmark Sunil K Pandey
2021-11-15 21:06 ` [PATCH v3 3/6] x86-64: Add vector exp/expf " Sunil K Pandey
2021-11-15 21:06 ` [PATCH v3 4/6] x86-64: Add vector log/logf " Sunil K Pandey
2021-11-15 21:06 ` [PATCH v3 5/6] x86-64: Add vector pow/powf " Sunil K Pandey
2021-11-15 21:06 ` [PATCH v3 6/6] x86-64: Add vector sin/sinf " Sunil K Pandey
2021-11-12 19:17 ` [PATCH v2 2/6] x86-64: Add vector cos/cosf " Sunil K Pandey
2021-11-12 19:17 ` [PATCH v2 3/6] x86-64: Add vector exp/expf " Sunil K Pandey
2021-11-12 19:17 ` [PATCH v2 4/6] x86-64: Add vector log/logf " Sunil K Pandey
2021-11-12 23:18 ` Joseph Myers
2021-11-13 1:37 ` Sunil Pandey
2021-11-13 1:44 ` Joseph Myers
2021-11-13 6:14 ` Sunil Pandey
2021-11-16 0:12 ` Joseph Myers
2021-11-23 17:40 ` [PATCH v4 0/5] Add vector math functions to microbenchmark Sunil K Pandey
2021-11-23 17:40 ` [PATCH v4 1/5] x86-64: Add vector cos/cosf to libmvec microbenchmark Sunil K Pandey
2021-11-24 12:22 ` H.J. Lu
2021-11-23 17:40 ` [PATCH v4 2/5] x86-64: Add vector exp/expf " Sunil K Pandey
2021-11-24 12:24 ` H.J. Lu
2021-11-23 17:40 ` [PATCH v4 3/5] x86-64: Add vector log/logf " Sunil K Pandey
2021-11-24 12:25 ` H.J. Lu
2021-11-23 17:40 ` [PATCH v4 4/5] x86-64: Add vector pow/powf " Sunil K Pandey
2021-11-24 12:26 ` H.J. Lu
2021-11-23 17:40 ` [PATCH v4 5/5] x86-64: Add vector sin/sinf " Sunil K Pandey
2021-11-24 12:30 ` H.J. Lu
2021-11-23 18:30 ` [PATCH v2 4/6] x86-64: Add vector log/logf " Sunil Pandey
2021-11-23 22:13 ` Joseph Myers
2021-11-12 19:17 ` [PATCH v2 5/6] x86-64: Add vector pow/powf " Sunil K Pandey
2021-11-12 19:18 ` [PATCH v2 6/6] x86-64: Add vector sin/sinf " Sunil K Pandey
2021-11-10 3:07 ` [PATCH 2/6] x86-64: Add cos/cosf " Sunil K Pandey
2021-11-10 3:07 ` [PATCH 3/6] x86-64: Add exp/expf " Sunil K Pandey
2021-11-10 3:07 ` [PATCH 4/6] x86-64: Add log/logf " Sunil K Pandey
2021-11-10 3:07 ` [PATCH 5/6] x86-64: Add pow/powf " Sunil K Pandey
2021-11-10 20:27 ` Joseph Myers
2021-11-11 3:31 ` Sunil Pandey [this message]
2021-11-11 10:39 ` Szabolcs Nagy
2021-11-11 17:40 ` Sunil Pandey
2021-11-11 18:51 ` Sunil Pandey
2021-11-10 3:07 ` [PATCH 6/6] x86-64: Add sin/sinf " Sunil K Pandey
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