[FFmpeg-devel] check_func() from configure & "math.h"

Måns Rullgård mans
Wed Aug 19 12:23:15 CEST 2009

ami_stuff <ami_stuff at o2.pl> writes:

>> > I have defined functions like lrint/lrintf/log2/round/roundf in the
>> > "math.h" include.  When I run "configure", it can't find them, so I
>> > must always define them manually to 1 in the "config.h" file.
>> >
>> > Maybe it would be possible to also add check for functions in the
>> > "math.h", not only in the linkable libs?
>> The standard requires those functions in the library.  Redo your homework.
> But functions in library probably would be slower.

Read the spec.  If you think you did, do it again.  Repeat until you
*understand* it.

You're allowed to provide whatever magic you like, but you must
provide external definitions for these functions in the library as

Besides, doesn't gcc have builtins for these functions anyway?

M?ns Rullg?rd
mans at mansr.com

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