Function neon_fp4_lut

csrc/cpu_ops.cpp:72–81

ARM NEON FP4 lookup table

// ARM NEON FP4 lookup table
static inline void neon_fp4_lut(float32x4_t lut[4]) {
    static const float fp4_values[16] = {
        0.0f, 5.208333333e-03f,  0.66666667f,  1.0f,  0.33333333f,  0.5f,  0.16666667f,  0.25f,
        0.0f, -5.208333333e-03f, -0.66666667f, -1.0f, -0.33333333f, -0.5f, -0.16666667f, -0.25f
    };
    lut[0] = vld1q_f32(fp4_values);
    lut[1] = vld1q_f32(fp4_values + 4);
    lut[2] = vld1q_f32(fp4_values + 8);
    lut[3] = vld1q_f32(fp4_values + 12);
}

// Efficient NEON float LUT lookup using indexed lane extraction
// The LUT has 16 float entries stored as a flat array for direct indexing