## astc-encoder CMakeLists.txt: auto detect SIMD Intrinsics
set(lib_name astc)
set(target_name ${lib_name})

project(${lib_name})

include(CheckIncludeFile)
include(CheckCCompilerFlag)
include(CheckCSourceCompiles)
include(CheckCXXSourceCompiles)

include(../cmake/CocosExternalConfig.cmake)

set(${target_name}_src
    astcenc_averages_and_directions.cpp
    astcenc_block_sizes.cpp
    astcenc_color_quantize.cpp
    astcenc_color_unquantize.cpp
    astcenc_compress_symbolic.cpp
    astcenc_compute_variance.cpp
    astcenc_decompress_symbolic.cpp
    astcenc_diagnostic_trace.cpp
    astcenc_entry.cpp
    astcenc_find_best_partitioning.cpp
    astcenc_ideal_endpoints_and_weights.cpp
    astcenc_image.cpp
    astcenc_integer_sequence.cpp
    astcenc_mathlib.cpp
    astcenc_mathlib_softfloat.cpp
    astcenc_partition_tables.cpp
    astcenc_percentile_tables.cpp
    astcenc_pick_best_endpoint_format.cpp
    astcenc_platform_isa_detection.cpp
    astcenc_quantization.cpp
    astcenc_symbolic_physical.cpp
    astcenc_weight_align.cpp
    astcenc_weight_quant_xfer_tables.cpp
)

add_library(${target_name} STATIC
  ${${target_name}_src}
)

# target_compile_definitions(${target_name}
#            PUBLIC ASTCENC_DECOMPRESS_ONLY)
            
if (NOT DEFINED ISA_SIMD)
    ### check -msse2 flag

    set(OLD_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
    if(MSVC)
        set(CMAKE_REQUIRED_FLAGS "${OLD_REQUIRED_FLAGS} /WX")
        check_c_compiler_flag("/arch:SSE2" ASTC_HAVE_SSE2_SWITCH)  
    else()
        set(CMAKE_REQUIRED_FLAGS "${OLD_REQUIRED_FLAGS} -Werror")
        check_c_compiler_flag(-msse2 ASTC_HAVE_SSE2_SWITCH)
    endif()
    if (ASTC_HAVE_SSE2_SWITCH)
        set(ASTC_HAVE_SSE2_INTRINSICS 1)
    endif()
    ### end check -msse2 flag

    if (NOT (ARCH_ALIAS STREQUAL "x86"))
        # Checking intel SIMD Intrinsics
        if(APPLE)
            set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -mpopcnt")
        endif()
        check_c_source_compiles("#include <immintrin.h>
            #include <stdint.h>
            int main()
            {
                __m256 m = _mm256_set_ps(1.f, 2.f, 3.f, 4.f, 5.f, 6.f, 7.f, 8.f);
                return (int)*(float*)&m;
            }" ASTC_HAVE_AVX2_INTRINSICS)
        check_c_source_compiles("#include <nmmintrin.h>
            #include <stdint.h>
            int main()
            {
                uint32_t v = 0;
                return (int)_mm_popcnt_u32(v);
            }" ASTC_HAVE_SSE42_INTRINSICS)
        check_c_source_compiles("#include <smmintrin.h>
            #include <stdint.h>
            int main()
            {
                __m128i shuf = _mm_set_epi8(0,0,0,0, 0,0,0,0, 0,0,0,0, 12,8,4,0);
                return *(int*)&shuf;
            }" ASTC_HAVE_SSE41_INTRINSICS)

        if (NOT ASTC_HAVE_SSE2_INTRINSICS)
            check_c_source_compiles("#include <emmintrin.h>
                #include <stdint.h>
                int main()
                {
                    __m128d m = _mm_set_sd(0.0); 
                    return (int)*(double*)&m;
                }" ASTC_HAVE_SSE2_INTRINSICS)
        endif()

        ### Checking ARM SIMD neon
        check_include_file(arm_neon.h ASTC_HAVE_ARM_NEON_H)
        if(ASTC_HAVE_ARM_NEON_H)
            set(CMAKE_REQUIRED_FLAGS "-std=c++11")
            check_cxx_source_compiles("#include <arm_neon.h>
                    int main()
                    {
                        int32x4_t ret4 = vdupq_n_s32(0);
                        uint32x4_t v{};
                        float16x4_t f16 = vcvt_f16_f32(v);
                        return vgetq_lane_s32(ret4, 0);
                    }" ASTC_HAVE_NEON_INTRINSICS)
        endif()

        ### restore CMAKE_REQUIRED_FLAGS
        set(CMAKE_REQUIRED_FLAGS ${OLD_REQUIRED_FLAGS})
        unset(OLD_REQUIRED_FLAGS) 
    else()
        message(AUTHOR_WARNING "Skipping AVX2/SSE4/NEON detection for astc-encoder when build x86 target")
    endif()

    ### set ISA_SIMD
    if(ASTC_HAVE_AVX2_INTRINSICS)
        set(ISA_SIMD "avx2")
    elseif(ASTC_HAVE_SSE42_INTRINSICS)
        set(ISA_SIMD "sse4.2")
    elseif(ASTC_HAVE_SSE41_INTRINSICS)
        set(ISA_SIMD "sse4.1")
    elseif(ASTC_HAVE_SSE2_INTRINSICS)
        set(ISA_SIMD "sse2")
    elseif(ASTC_HAVE_NEON_INTRINSICS)
        set(ISA_SIMD "neon")
    else()
        set(ISA_SIMD "none")
    endif() 

    message(AUTHOR_WARNING "ISA_SIMD=${ISA_SIMD},ASTC_HAVE_AVX2_INTRINSICS=${ASTC_HAVE_AVX2_INTRINSICS},ASTC_HAVE_SSE42_INTRINSICS=${ASTC_HAVE_SSE42_INTRINSICS},ASTC_HAVE_SSE41_INTRINSICS=${ASTC_HAVE_SSE41_INTRINSICS},ASTC_HAVE_SSE2_INTRINSICS=${ASTC_HAVE_SSE2_INTRINSICS},ASTC_HAVE_NEON_INTRINSICS=${ASTC_HAVE_NEON_INTRINSICS}")
endif()

# Set up configuration for SIMD ISA builds
if(${ISA_SIMD} MATCHES "none")
    target_compile_definitions(${target_name}
        PUBLIC
            ASTCENC_NEON=0
            ASTCENC_SSE=0
            ASTCENC_AVX=0
            ASTCENC_POPCNT=0
            ASTCENC_F16C=0)
elseif(${ISA_SIMD} MATCHES "neon")
    target_compile_definitions(${target_name}
        PUBLIC
            ASTCENC_NEON=1
            ASTCENC_SSE=0
            ASTCENC_AVX=0
            ASTCENC_POPCNT=0
            ASTCENC_F16C=0)
elseif(${ISA_SIMD} MATCHES "avx2")
    target_compile_definitions(${target_name}
        PUBLIC
            ASTCENC_NEON=0
            ASTCENC_SSE=42
            ASTCENC_AVX=2
            ASTCENC_POPCNT=1
            ASTCENC_F16C=1)

    target_compile_options(${target_name}
        PRIVATE
            $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-mavx2 -mpopcnt -mf16c>
            $<$<CXX_COMPILER_ID:MSVC>:/arch:AVX2>)
elseif(${ISA_SIMD} MATCHES "sse4.2")
    target_compile_definitions(${target_name}
        PUBLIC
            ASTCENC_NEON=0
            ASTCENC_SSE=42
            ASTCENC_AVX=0
            ASTCENC_POPCNT=1
            ASTCENC_F16C=0)

    target_compile_options(${target_name}
        PRIVATE
            $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-msse4.2 -mpopcnt>)
elseif(${ISA_SIMD} MATCHES "sse4.1")
    target_compile_definitions(${target_name}
        PUBLIC
            ASTCENC_NEON=0
            ASTCENC_SSE=41
            ASTCENC_AVX=0
            ASTCENC_POPCNT=1
            ASTCENC_F16C=0)

    target_compile_options(${target_name}
        PRIVATE
            $<$<NOT:$<CXX_COMPILER_ID:MSVC>>:-msse4.1 -mpopcnt>)
elseif(${ISA_SIMD} MATCHES "sse2")
    target_compile_definitions(${target_name}
        PUBLIC
            ASTCENC_NEON=0
            ASTCENC_SSE=20
            ASTCENC_AVX=0
            ASTCENC_POPCNT=0
            ASTCENC_F16C=0)
endif()

target_include_directories(${target_name} PUBLIC ..)