Easiest way to use FMA instruction

[Ben Jones via Digitalmars-d-learn]

What's the easiest way to use the FMA instruction (fused multiply 
add that has nice rounding properties)?  The FMA function in 
Phobos just does a*b +c  which will round twice.

Do any of the intrinsics libraries include this?  Should I write 
my own inline ASM?