Remaining intrinsics work:

[sezero]

Left over stuff after https://github.com/libsdl-org/SDL/pull/7490 :

• [ ] Cmake SIMD feature tests use -mXXX switches, the build itself doesn't: https://github.com/libsdl-org/SDL/pull/7490#issuecomment-1477428226 Not a real show-stopper, but the cmake detection can be a lie: clang-cl is a good example.
• [x] RDTSC option can probably go away and be made into a macro: https://github.com/libsdl-org/SDL/pull/7490#pullrequestreview-1350050161
  • Done with https://github.com/libsdl-org/SDL/pull/7516
• [x] Intel compiler hanling: It seems to support target attributes, but I don't know since which version: https://www.intel.com/content/www/us/en/docs/cpp-compiler/developer-guide-reference/2021-8/attributes.html
  • Done with https://github.com/libsdl-org/SDL/pull/7516
• [ ] Handling ARM / NEON intrinsics similarly: Don't know how to handle.
• [ ] Handling PowerPC ALTIVEC similarly: Don't know how to handle.
• [ ] Handling LSX and LASX intrinsics similarly: Don't know how to handle (I don't even know where to find those two lsxintrin.h and lasxintrin.h headers.)

[sezero]

@madebr: About rdtsc:

As of gcc-4.5.x, __rdtsc() is available from x86intrin.h (which includes ia32intrin.h), and _rdtsc() has always been defined as __rdtsc. See: https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config/i386/ia32intrin.h;hb=HEAD#l313

As of clang-3.5: same behavior as gcc. Clang as of 4.0, however, made __rdtsc() simply a builtin function, ia32intrin.h (included by x86intrin.h as usual) still defines _rdtsc as __rdtsc as it used to.

I.e.: Neither of gcc or clang actually need immintrin.h for rdtsc but only x86intrin.h, as of above-mentioned versions which go much older than what we expect in current SDL_intrin.h.

[icculus]

Handling ARM / NEON intrinsics similarly: Don't know how to handle. Handling PowerPC ALTIVEC similarly: Don't know how to handle.

Does this just need something like SDL_TARGETING("altivec") or is it more complicated than that?

[sezero]

Handling ARM / NEON intrinsics similarly: Don't know how to handle. Handling PowerPC ALTIVEC similarly: Don't know how to handle.

Does this just need something like SDL_TARGETING("altivec") or is it more complicated than that?

Don't really know whether the target attributes work for those targets, hence the "don't know how to handle" notes