Function core_arch::x86::_mm_fmadd_sd

pub unsafe fn _mm_fmadd_sd(a: __m128d, b: __m128d, c: __m128d) -> __m128d

This is supported on x86 and target feature fma only.

Multiplies the lower double-precision (64-bit) floating-point elements in a and b, and add the intermediate result to the lower element in c. Stores the result in the lower element of the returned value, and copy the upper element from a to the upper elements of the result.

Intel's documentation