From: Patrick McGehearty <patrick.mcgehearty@oracle.com>
To: Joseph Myers <joseph@codesourcery.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH] Improves __ieee754_exp() performance by greater than 5x on sparc/x86.
Date: Sat, 21 Oct 2017 05:23:00 -0000 [thread overview]
Message-ID: <c2d58c79-2902-579d-d06d-9ce427fcac77@oracle.com> (raw)
In-Reply-To: <alpine.DEB.2.20.1710192235050.9397@digraph.polyomino.org.uk>
On 10/19/2017 5:48 PM, Joseph Myers wrote:
> On Thu, 19 Oct 2017, Patrick McGehearty wrote:
>
>
>>> Guaranteeing "inexact" is not part of the goals for most libm functions,
>>> so I expect you can remove that term.
>> The "inexact" test was required to pass the (make check) math lib tests.
> You'll need to explain more. For functions which are not fully defined by
> a binding to IEEE operations, both spurious and missing "inexact" should
> be allowed by the testsuite.
>
When the following lines are commented out:
    double force_underflow = tiny * tiny;
    math_force_eval (force_underflow);
The following failures appear (plus repeated for other rounding modes)
Failure: exp (-0x2.c4edp+12): Exception "Underflow" not set
Failure: exp (-0x2.c5b2319c4843ap+12): Exception "Underflow" not set
Failure: exp (-0x2.c5b2319c4843cp+12): Exception "Underflow" not set
Failure: exp (-0x2.c5b234p+12): Exception "Underflow" not set
Failure: exp (-0x2.c5b23p+12): Exception "Underflow" not set
Failure: exp (-0x2.c5bd48bdc7c0cp+12): Exception "Underflow" not set
Failure: exp (-0x2.c5bd48bdc7c0ep+12): Exception "Underflow" not set
Failure: exp (-0x2.c5bd48p+12): Exception "Underflow" not set
Failure: exp (-0x2.c5bd4cp+12): Exception "Underflow" not set
Failure: exp (-0x2.ebe224p+8): Exception "Underflow" not set
Failure: exp (-0x2.ebe227861639p+8): Exception "Underflow" not set
Failure: exp (-0x2.ebe228p+8): Exception "Underflow" not set
Failure: exp (-0x4.d2p+8): Exception "Underflow" not set
Failure: exp (-0xf.ffffffffffff8p+1020): Exception "Underflow" not set
Failure: exp (-0xf.fffffp+124): Exception "Underflow" not set
The same pair of instructions are used in the old e_exp.c
to set the underflow exception, which means the new code
will match the behavior of the old code for underflows.
- patrick
next prev parent reply other threads:[~2017-10-21 5:23 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-16 16:56 Patrick McGehearty
2017-10-18 17:22 ` Joseph Myers
2017-10-18 23:22 ` Joseph Myers
2017-10-19 22:31 ` Patrick McGehearty
2017-10-19 22:48 ` Joseph Myers
2017-10-20 15:04 ` Patrick McGehearty
2017-10-21 5:23 ` Patrick McGehearty [this message]
2017-10-23 12:47 ` Joseph Myers
2017-10-23 19:58 ` Patrick McGehearty
2017-10-23 21:31 ` Joseph Myers
2017-10-20 11:41 ` Szabolcs Nagy
2017-10-20 14:56 ` Patrick McGehearty
2017-10-20 16:10 ` Joseph Myers
2017-10-23 12:25 ` Siddhesh Poyarekar
2017-10-23 15:58 ` Joseph Myers
2017-10-20 13:38 Wilco Dijkstra
2017-10-20 14:58 ` Patrick McGehearty
2017-10-26 16:44 Patrick McGehearty
2017-10-26 17:20 ` Joseph Myers
2017-10-26 17:25 ` Joseph Myers
2017-10-26 18:30 ` Patrick McGehearty
2017-10-26 19:44 ` Joseph Myers
2017-10-26 22:53 Patrick McGehearty
2017-11-01 0:26 ` Joseph Myers
2017-11-07 4:25 Patrick McGehearty
2017-11-16 17:52 ` Patrick McGehearty
2017-11-16 18:27 ` Carlos O'Donell
2017-11-16 18:31 ` Joseph Myers
2017-11-23 21:19 ` Joseph Myers
2017-12-01 0:47 ` Patrick McGehearty
2017-12-01 0:51 Patrick McGehearty
2017-12-01 0:56 ` Joseph Myers
2017-12-04 21:53 Patrick McGehearty
2017-12-05 23:20 ` Joseph Myers
2017-12-08 23:08 Patrick McGehearty
2017-12-11 8:14 ` Siddhesh Poyarekar
2017-12-11 17:04 ` Patrick McGehearty
2017-12-11 17:53 ` Siddhesh Poyarekar
2017-12-14 1:28 ` Joseph Myers
2017-12-18 20:11 ` Patrick McGehearty
2017-12-29 23:42 Patrick McGehearty
2018-01-01 1:36 ` Joseph Myers
2018-01-01 16:31 ` Patrick McGehearty
2018-01-01 16:41 ` Joseph Myers
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