cmake: enable x86 and neon simd for Apple multi-arch configurations

Reference issue libsdl-org#12731

Author: sezero

CMakeLists.txt

@@ -679,6 +679,10 @@ if(SDL_ASSEMBLY)
   set(HAVE_ASSEMBLY TRUE)
 
   if(SDL_MMX)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_MMX TRUE)
+    message(STATUS "SIMD: MMX enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mmmx")
@@ -698,8 +702,13 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_MMX)
       set(HAVE_MMX TRUE)
     endif()
+   endif()
   endif()
   if(SDL_SSE)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_SSE TRUE)
+    message(STATUS "SIMD: SSE enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse")
@@ -719,8 +728,13 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_SSE)
       set(HAVE_SSE TRUE)
     endif()
+   endif()
   endif()
   if(SDL_SSE2)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_SSE2 TRUE)
+    message(STATUS "SIMD: SSE2 enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse2")
@@ -740,8 +754,13 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_SSE2)
       set(HAVE_SSE2 TRUE)
     endif()
+   endif()
   endif()
   if(SDL_SSE3)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_SSE3 TRUE)
+    message(STATUS "SIMD: SSE3 enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse3")
@@ -762,7 +781,12 @@ if(SDL_ASSEMBLY)
       set(HAVE_SSE3 TRUE)
     endif()
   endif()
+  endif()
   if(SDL_SSE4_1)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_SSE4_1 TRUE)
+    message(STATUS "SIMD: SSE4.1 enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse4.1")
@@ -782,8 +806,13 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_SSE4_1)
       set(HAVE_SSE4_1 TRUE)
     endif()
+   endif()
   endif()
   if(SDL_SSE4_2)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_SSE4_2 TRUE)
+    message(STATUS "SIMD: SSE4.2 enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -msse4.2")
@@ -800,8 +829,13 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_SSE4_2)
       set(HAVE_SSE4_2 TRUE)
     endif()
+   endif()
   endif()
   if(SDL_AVX)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_AVX TRUE)
+    message(STATUS "SIMD: AVX enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mavx")
@@ -821,8 +855,13 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_AVX)
       set(HAVE_AVX TRUE)
     endif()
+   endif()
   endif()
   if(SDL_AVX2)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_AVX2 TRUE)
+    message(STATUS "SIMD: AVX2 enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mavx2")
@@ -842,8 +881,13 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_AVX2)
       set(HAVE_AVX2 TRUE)
     endif()
+   endif()
   endif()
   if(SDL_AVX512F)
+   if(APPLE_MULTIARCH AND SDL_CPU_X64)
+    set(HAVE_AVX512F TRUE)
+    message(STATUS "SIMD: AVX512F enabled for Apple multi-arch config")
+   else()
     cmake_push_check_state()
     if(USE_GCC OR USE_CLANG OR USE_INTELCC)
       string(APPEND CMAKE_REQUIRED_FLAGS " -mavx512f")
@@ -863,9 +907,14 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_AVX512F)
       set(HAVE_AVX512F TRUE)
     endif()
+   endif()
   endif()
 
   if(SDL_ARMNEON)
+   if(APPLE_MULTIARCH AND SDL_CPU_ARM64)
+    set(HAVE_ARMNEON TRUE)
+    message(STATUS "SIMD: NEON enabled for Apple multi-arch config")
+   else()
     check_c_source_compiles("
         #include <arm_neon.h>
         void floats_add(float *dest, float *a, float *b, unsigned size) {
@@ -881,6 +930,7 @@ if(SDL_ASSEMBLY)
     if(COMPILER_SUPPORTS_ARMNEON)
       set(HAVE_ARMNEON TRUE)
     endif()
+   endif()
   endif()
 
   if(USE_GCC OR USE_CLANG)

cmake/sdlcpu.cmake

@@ -3,6 +3,10 @@ function(SDL_DetectTargetCPUArchitectures DETECTED_ARCHS)
   set(known_archs EMSCRIPTEN ARM32 ARM64 ARM64EC LOONGARCH64 POWERPC32 POWERPC64 X86 X64)
 
   if(APPLE AND CMAKE_OSX_ARCHITECTURES)
+    list(LENGTH CMAKE_OSX_ARCHITECTURES _num_arches)
+    if(_num_arches GREATER 1)
+      set(APPLE_MULTIARCH 1 PARENT_SCOPE)
+    endif()
     foreach(known_arch IN LISTS known_archs)
       set(SDL_CPU_${known_arch} "0" PARENT_SCOPE)
     endforeach()