/* https://cirosantilli.com/linux-kernel-module-cheat#gcc-intrinsics */

#include <assert.h>
#include <inttypes.h>
#include <string.h>

#include <x86intrin.h>

uint32_t global_input0[] __attribute__((aligned(16))) = {1, 2, 3, 4};
uint32_t global_input1[] __attribute__((aligned(16))) = {5, 6, 7, 8};
uint32_t global_output[4] __attribute__((aligned(16)));
uint32_t global_expected[] __attribute__((aligned(16))) = {6, 8, 10, 12};

int main(void) {

    /* 32-bit add hello world. */
    {
        __m128i input0 = _mm_set_epi32(1, 2, 3, 4);
        __m128i input1 = _mm_set_epi32(5, 6, 7, 8);
        __m128i output = _mm_add_epi32(input0, input1);
        /* _mm_extract_epi32 mentioned at:
         * https://stackoverflow.com/questions/12495467/how-to-store-the-contents-of-a-m128d-simd-vector-as-doubles-without-accessing/56404421#56404421 */
        assert(_mm_extract_epi32(output, 3) == 6);
        assert(_mm_extract_epi32(output, 2) == 8);
        assert(_mm_extract_epi32(output, 1) == 10);
        assert(_mm_extract_epi32(output, 0) == 12);
    }

    /* Now from memory. */
    {
        __m128i *input0 = (__m128i *)global_input0;
        __m128i *input1 = (__m128i *)global_input1;
        _mm_store_si128((__m128i *)global_output, _mm_add_epi32(*input0, *input1));
        assert(!memcmp(global_output, global_expected, sizeof(global_output)));
    }

    /* Now a bunch of other sizes. */
    {
        __m128i input0 = _mm_set_epi32(0xF1F1F1F1, 0xF2F2F2F2, 0xF3F3F3F3, 0xF4F4F4F4);
        __m128i input1 = _mm_set_epi32(0x12121212, 0x13131313, 0x14141414, 0x15151515);
        __m128i output;

        /* 8-bit integers (paddb) */
        output = _mm_add_epi8(input0, input1);
        assert(_mm_extract_epi32(output, 3) == 0x03030303);
        assert(_mm_extract_epi32(output, 2) == 0x05050505);
        assert(_mm_extract_epi32(output, 1) == 0x07070707);
        assert(_mm_extract_epi32(output, 0) == 0x09090909);

        /* 32-bit integers (paddw) */
        output = _mm_add_epi16(input0, input1);
        assert(_mm_extract_epi32(output, 3) == 0x04030403);
        assert(_mm_extract_epi32(output, 2) == 0x06050605);
        assert(_mm_extract_epi32(output, 1) == 0x08070807);
        assert(_mm_extract_epi32(output, 0) == 0x0A090A09);

        /* 32-bit integers (paddd) */
        output = _mm_add_epi32(input0, input1);
        assert(_mm_extract_epi32(output, 3) == 0x04040403);
        assert(_mm_extract_epi32(output, 2) == 0x06060605);
        assert(_mm_extract_epi32(output, 1) == 0x08080807);
        assert(_mm_extract_epi32(output, 0) == 0x0A0A0A09);

        /* 64-bit integers (paddq) */
        output = _mm_add_epi64(input0, input1);
        assert(_mm_extract_epi32(output, 3) == 0x04040404);
        assert(_mm_extract_epi32(output, 2) == 0x06060605);
        assert(_mm_extract_epi32(output, 1) == 0x08080808);
        assert(_mm_extract_epi32(output, 0) == 0x0A0A0A09);
    }

    return 0;
}