Tiemo Jung
All CPU detection functions SDL_Has* will return false, even if it is supported by the CPU, if SDL is compiled with MSVC and the target is x64.
The reason for this is that 'CPU_haveCPUID' will return 0 and macro 'cpuid' in SDL_cpuinfo.c is the fallback implementation, which sets all params to zero.
It is safe to assume that cpuid is supported on a CPU that runs windows x64, so CPU_haveCPUID can just return 1, and the empty macro can be replaced with a small wrap around the __cpuid intrinsic.
Felix Geyer
Starting from version 2.0.1 libsdl fails to build on Debian GNU/kFreeBSD in SDL_cpuinfo.c.
GNU/kFreeBSD defines __FreeBSD_kernel__ but not __FreeBSD__.
The #ifdef __FreeBSD__ check should be extended for __FreeBSD_kernel__, see the attached patch.
Build log:
libtool: compile: gcc -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -D_FORTIFY_SOURCE=2 -DUSING_GENERATED_CONFIG_H -Iinclude -I/?BUILDDIR?/libsdl2-2.0.1+dfsg1/include -mmmx -m3dnow -msse -msse2 -fvisibility=hidden -D_REENTRANT -I/usr/include/dbus-1.0 -I/usr/lib/x86_64-kfreebsd-gnu/dbus-1.0/include -DHAVE_USBHID_H -DUSBHID_NEW -D_REENTRANT -Wall -c /?BUILDDIR?/libsdl2-2.0.1+dfsg1/src/cpuinfo/SDL_cpuinfo.c -fPIC -DPIC -o build/.libs/SDL_cpuinfo.o
/?BUILDDIR?/libsdl2-2.0.1+dfsg1/src/cpuinfo/SDL_cpuinfo.c: In function 'SDL_GetSystemRAM':
/?BUILDDIR?/libsdl2-2.0.1+dfsg1/src/cpuinfo/SDL_cpuinfo.c:632:35: error: 'HW_MEMSIZE' undeclared (first use in this function)
int mib[2] = {CTL_HW, HW_MEMSIZE};
^
/?BUILDDIR?/libsdl2-2.0.1+dfsg1/src/cpuinfo/SDL_cpuinfo.c:632:35: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [build/SDL_cpuinfo.lo] Error 1
Haneef Mubarak
AVX is the successor to SSE* and is fairly widely available. As such, it really ought to be detectable.
This functionality ought to be trivial to implement, and not having it means being forced to write an ugly workaround to check for AVX (so that normal SSE can be used if AVX is not available).
Here is an example on detecting AVX from SO (it actually shows ways to cehck for all of teh fancy instructions):
http://stackoverflow.com/questions/6121792/how-to-check-if-a-cpu-supports-the-sse3-instruction-set
Ryan C. Gordon
Sam Lantinga
Gabriel Jacobo