NetBSD Problem Report #52269

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Date: Fri,  2 Jun 2017 19:29:42 +0000 (UTC)
From: coypu@sdf.org
Reply-To: coypu@sdf.org
To: gnats-bugs@NetBSD.org
Subject: ctan(1+1000i) is incorrect
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>Number:         52269
>Category:       lib
>Synopsis:       ctan(1+1000i) is incorrect
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jun 02 19:30:00 +0000 2017
>Last-Modified:  Mon Nov 13 19:24:27 +0000 2017
>Originator:     coypu
>Release:        NetBSD 7.99.75
>Organization:
>Environment:
NetBSD loggy 7.99.75 NetBSD 7.99.75 (GENERIC) #61: Fri Jun  2 10:34:58 IDT 2017  fly@loggy:/home/fly/obj/sys/arch/amd64/compile/GENERIC amd64

>Description:
#include <complex.h>
#include <math.h>
#include <stdio.h>


int main() {
	printf("%f\n", ctan(1 + 1000*I));
}

$ gcc test2.c -lm
$ ./a.out
nan

expected: a number.
>How-To-Repeat:
Run R testsuite.
>Fix:
problem lies in using trigonometric functions which overflow in arg>=710.5 (some correctly)

maybe private taylor expansion is needed.

>Release-Note:

>Audit-Trail:

Responsible-Changed-From-To: lib-bug-people->maya
Responsible-Changed-By: maya@NetBSD.org
Responsible-Changed-When: Fri, 02 Jun 2017 19:30:48 +0000
Responsible-Changed-Why:
Don't want this case to be resolved by importing all of freebsd libm and blindly breaking shit.


Responsible-Changed-From-To: maya->lib-bug-people
Responsible-Changed-By: maya@NetBSD.org
Responsible-Changed-When: Mon, 13 Nov 2017 19:24:27 +0000
Responsible-Changed-Why:


>Unformatted:

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