Error : casting user defined data types in c

Question

This is a simpler view of my Problem, I want to convert a float value into defined type v4si (I want to use SIMD Operation for optimization.) Please help to convert float/do

Answer 1

You don't need to define a custom SIMD vector type (v4si) or mess around with casts and type punning - just use the provided intrinsics in the appropriate *intrin.h header, e.g.

#include  // use SSE intrinsics 

int main(void)
{
    __m128 v;          // __m128 is the standard SSE vector type for 4 x float
    float x, y, z, w;

    v = _mm_set_ps(x, y, z, w);
                       // use intrinsic to set vector contents to x, y, z, w

    // ...

    return 0;
}