With this commit, you can compile SDL2 with Emscripten
( http://emscripten.org/ ), and make your SDL-based C/C++ program
into a web app.
This port was due to the efforts of several people, including: Charlie Birks,
Sathyanarayanan Gunasekaran, Jukka Jylänki, Alon Zakai, Edward Rudd,
Bruce Mitchener, and Martin Gerhardy. (Thanks, everyone!)
The _xgetbv intrinsic was being used in ARM builds of SDL/WinRT, which was
leading to linker errors. This commit limits _xgetbv use to the platforms on
which it is available, x86 and x64.
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
Andreas Ertelt
The problem in question is caused by changeset 7771 (http://hg.libsdl.org/SDL/rev/4434498bf4b9 / https://bugzilla.libsdl.org/show_bug.cgi?id=2121)
The redefinition of __inline__ (introduced by the addition of begin_code.h:128's "|| __STRICT_ANSI__") results in mingw's gcc throwing multiple
warning: always_inline function might not be inlinable [-Wattributes]
as well as a whole bunch of redefinitions of mingw internals which break linking of projects including the SDL2 headers.
Marcus von Appen
Revision c47ae79f0de8 of the SDL hg repo introduces the new
SDL_GetSystemRAM() function, which breaks the build on FreeBSD. Find
attached a patch, which unbreaks the build and also should (for most
cases) properly implement the sysctl support it.
