[flac-dev] Two questions about RG in flac

[Robert Kausch]

Am 03.06.2014 16:45, schrieb lvqcl:
> 2) to ALL:
> I attached a small program. Compile and run it.
> * Does it work correctly when compiled with -O3 -msse2 options?
> * If yes, does it work correctly when compiled with -O3 -funroll-loops 
> -msse2 options?
>   ( and what is the version of your GCC? )
Tested various versions of TDM-GCC on Windows.

32 bit executable produced with TDM-GCC 4.8.1 fails as soon as -O3 and 
SSE2 come together. SSE2 is enabled by -O3 here, so compiling with -O3 
is sufficient to trigger the bug. Compiling with -O3 -mno-sse2 produces 
a correctly working executable just as -O2 -msse2 does. -funroll-loops 
does not make any difference.

Same with TDM-GCC 4.4.1, 4.5.0, 4.6.1 and 4.7.1; only difference is that 
-O3 does not include SSE2 there, so it has to be enabled manually with 
-msse2 to trigger the problem.

TDM-GCC 4.3.2 produces a correctly working executable even with -O3 -msse2.

64 bit executables produced with any of the tested GCC versions work 
correctly in all cases.