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troosh/movemask.c

Forked from mhroth/movemask.c
Created January 14, 2018 09:00
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A basic NEON implementation of SSE _mm_movemask_ps
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movemask.c
uint32_t _mm_movemask_ps(float32x4_t x) {
uint32x4_t mmA = vandq_u32(
vreinterpretq_u32_f32(x), (uint32x4_t) {0x1, 0x2, 0x4, 0x8}); // [0 1 2 3]
uint32x4_t mmB = vextq_u32(mmA, mmA, 2); // [2 3 0 1]
uint32x4_t mmC = vorrq_u32(mmA, mmB); // [0+2 1+3 0+2 1+3]
uint32x4_t mmD = vextq_u32(mmC, mmC, 3); // [1+3 0+2 1+3 0+2]
uint32x4_t mmE = vorrq_u32(mmC, mmD); // [0+1+2+3 ...]
return vgetq_lane_u32(mmE, 0);
}
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