From: Corinna Vinschen <vinschen@redhat.com>
To: Fabian Schriever <fabian.schriever@gtd-gmbh.de>
Cc: newlib@sourceware.org
Subject: Re: [PATCH] Fix hypotf missing mask in hi+lo decomposition
Date: Fri, 20 Mar 2020 10:16:03 +0100 [thread overview]
Message-ID: <20200320091603.GH778468@calimero.vinschen.de> (raw)
In-Reply-To: <20200319153408.1413-1-fabian.schriever@gtd-gmbh.de>
[-- Attachment #1: Type: text/plain, Size: 1457 bytes --]
On Mar 19 16:34, Fabian Schriever wrote:
> Add the missing mask for the decomposition of hi+lo which caused some
> errors of 1-2 ULP.
>
> This change is taken over from FreeBSD:
> https://github.com/freebsd/freebsd/commit/95436ce20dab5a34ba46373410b96411b1734578
>
> Additionally I've removed some variable assignments which were never
> read before being overwritten again in the next 2 lines.
> ---
> newlib/libm/math/ef_hypot.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/newlib/libm/math/ef_hypot.c b/newlib/libm/math/ef_hypot.c
> index 9368eb41c..a70c92b88 100644
> --- a/newlib/libm/math/ef_hypot.c
> +++ b/newlib/libm/math/ef_hypot.c
> @@ -29,7 +29,7 @@
> ha &= 0x7fffffffL;
> GET_FLOAT_WORD(hb,y);
> hb &= 0x7fffffffL;
> - if(hb > ha) {a=y;b=x;j=ha; ha=hb;hb=j;} else {a=x;b=y;}
> + if(hb > ha) { j = ha; ha = hb; hb = j; }
> SET_FLOAT_WORD(a,ha); /* a <- |a| */
> SET_FLOAT_WORD(b,hb); /* b <- |b| */
> if((ha-hb)>0xf000000L) {return a+b;} /* x/y > 2**30 */
> @@ -72,7 +72,7 @@
> a = a+a;
> SET_FLOAT_WORD(y1,hb&0xfffff000L);
> y2 = b - y1;
> - SET_FLOAT_WORD(t1,ha+0x00800000L);
> + SET_FLOAT_WORD(t1,(ha+0x00800000L)&0xfffff000UL);
> t2 = a - t1;
> w = __ieee754_sqrtf(t1*y1-(w*(-w)-(t1*y2+t2*b)));
> }
> --
> 2.24.1.windows.2
>
Pushed.
Thanks,
Corinna
--
Corinna Vinschen
Cygwin Maintainer
Red Hat
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
prev parent reply other threads:[~2020-03-20 9:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-19 15:34 Fabian Schriever
2020-03-19 22:27 ` Keith Packard
2020-03-20 9:16 ` Corinna Vinschen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200320091603.GH778468@calimero.vinschen.de \
--to=vinschen@redhat.com \
--cc=fabian.schriever@gtd-gmbh.de \
--cc=newlib@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).