取颜色Alpha值作为四分量

取颜色Alpha值作为四分量

颜色值为AARRGGBB变换后为AAAAAAAA
初始颜色为：
112233445566778899AABBCCDDEEFF00

    __m128i TC = _mm_set_epi32(0x11223344, 0x55667788, 0x99AABBCC, 0xDDEEFF00);
    TC = _mm_srli_epi32(TC, 24);
    TC = _mm_shufflelo_epi16(TC, 0xa0);
    TC = _mm_shufflehi_epi16(TC, 0xa0);
    __m128i p = _mm_load_si128(&TC);
    TC = _mm_slli_epi16(TC, 8);
    TC = _mm_or_si128(TC, p);

此时的TC应该为
111111115555555599999999DDDDDDDD