flac dev - Jul 2014 - uint64 -> double conversion

Anybody knows the reason for the following code
(you can see it in flac/decode.c, flac/encode.c, libFLAC/fixed.c and
libFLAC/stream_decoder.c) ?


#if defined _MSC_VER || defined __MINGW32__
     /* with MSVC you have to spoon feed it the casting */
     residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ?
log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_0 / (FLAC__double)data_len) /
M_LN2 : 0.0);
     ...
#else
     residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ?
log(M_LN2 * (FLAC__double)total_error_0 / (FLAC__double)data_len) / M_LN2 :
0.0);
     ...
#endif


IOW: use (FLAC__double)(FLAC__int64)some_uint64_variable for MSVC and MinGW
and (FLAC__double)some_uint64_variable for other compilers.

relevant patches:

http://git.xiph.org/?p=flac.git;a=commitdiff;h=59f4a995ddf0632241116bd69f6dc8c6f3ac790c
(april 2001)

http://git.xiph.org/?p=flac.git;a=commitdiff;h=40333b13c127bfb3c5f839fb59edbafa23d3ccbb
(this patch is probably just a mass rename from _MSC_VER to _MSC_VER +
__MINGW32__).


Is it MSVC6 specific? The following web pages seem to confirm this:
http://www.winehq.org/pipermail/wine-patches/2004-September/012502.html
https://mail.gnome.org/archives/commits-list/2012-July/msg01092.html

lvqcl wrote:
> Anybody knows the reason for the following code
> (you can see it in flac/decode.c, flac/encode.c, libFLAC/fixed.c and
> libFLAC/stream_decoder.c) ?
<snip>
> Is it MSVC6 specific? The following web pages seem to confirm this:
> http://www.winehq.org/pipermail/wine-patches/2004-September/012502.html
> https://mail.gnome.org/archives/commits-list/2012-July/msg01092.html
That's a really good question. Haven't was already dropped support for
MSVC6? If so, we should drop this #ifdef hackery. Can test this without
the hackery for versions of MSVC > 6?

Cheers,
Erik
-- 
----------------------------------------------------------------------
Erik de Castro Lopo
http://www.mega-nerd.com/

Erik de Castro Lopo wrote:
> That's a really good question. Haven't was already dropped support
for
> MSVC6? If so, we should drop this #ifdef hackery. Can test this without
> the hackery for versions of MSVC > 6?
I don't have VC 2002/2003, but the oldest Visual Studio that FLAC supports
is MSVS 2005 anyway. It can compile FLAC__uint64 -> FLAC__double conversion
without intermediate FLAC__int64. So this "spoon feed" isn't
necessary.


(found another place with this double conversion, inside
src/utils/flactimer/main.cpp. It also has unnecessary #defines
for int64_t/uint64_t)