Issue 91602

Summary:

provide ersatz for expm1 and log1p

Product:

porting

Reporter:

Regina Henschel <rb.henschel>

Component:

code

Assignee:

ooo

Status:

CLOSED FIXED

QA Contact:

issues@porting <issues>

Severity:

Trivial

Priority:

CC:

issues, ooo, stephan.bergmann.secondary

Version:

DEV300m20

Target Milestone:

OOo 3.1

Hardware:

All

OS:

Windows XP

Issue Type:

PATCH

Latest Confirmation in:

---

Developer Difficulty:

---

Issue Depends on:

Issue Blocks:

91547, 91870

Attachments:

Description	Flags
ersatz for expm1 and log1p, and test values	none
changes in patch form	none

Description Regina Henschel 2008-07-12 18:02:29 UTC

Working for Calc for BETADIST, I need the functions expm1 and log1p. But I
noticed, that they are not provided by MS Visual C++ 9.0 Express edition. (At
least I do not found them.) I have used a local ersatz. But I think such a
ersatz should be placed in a common place in a way that I can use expm1 and
log1p in my code and if a compiler has got them, the original version is used,
and if a compiler hasn't got them, the ersatz is used.

I'll attach a file with the ersatz, that works for me with MS Visual C++ 9.0
Express edition on WinXP home. But I don't know, which scenarios will need it
too and whether the ersatz will work there too.

Comment 1 Regina Henschel 2008-07-12 18:05:06 UTC

Created attachment 55086 [details]
ersatz for expm1 and log1p, and test values

Comment 2 ooo 2008-07-17 14:13:46 UTC

I think this should go into ::rtl::math where a wrapper would call either the
compiler provided function or the replacement. Stephan, what do you think?

Btw, is there a way to detect at compilation time whether a compiler supports
these functions, other than using #ifdef __MSC_VER or similar respectively the
usual configure attempt to test compile a function call?

Comment 3 Stephan Bergmann 2008-07-17 17:33:52 UTC

@er:  Yes, adding something to sal/inc/sal/math.h seems reasonable.  I am not
aware of a good way to test for existence of those functions in math.h; #if
__STDC_VERSION__ >= 199901L would work for C (conservatively), but not
necessarily for C++.

Comment 4 ooo 2008-07-17 18:32:19 UTC

Grabbing issue.

Comment 5 Regina Henschel 2008-12-03 13:34:41 UTC

Created attachment 58470 [details]
changes in patch form

Comment 6 ooo 2008-12-04 21:58:02 UTC

In cws odff05:

revision 264877
sal/inc/rtl/math.h
sal/inc/rtl/math.hxx
sal/rtl/source/math.cxx
sal/util/sal.map

A slightly different approach than the attached patch. This makes the functions
available to C sources as well, and provides one single point to change in case
we wanted to replace the replacements with compiler-builtins for specific platforms.

Comment 7 ooo 2008-12-11 13:54:21 UTC

Code present in CWS build.

Comment 8 ooo 2009-07-03 21:19:11 UTC

Available in masters, closing.