Who Is Vfmaddrnd231pd?

What happened
vfmaddrnd231pd is a unique instruction from the FMA instruction set. Most instructions in that set have mnemonics like vfmadd231pd, but here rnd means something very specific. The Intel Software Development Manual documents it as: VFMADDRND231PD – Fused Multiply-Add of Packed Double-Precision Floating-Point Values with rounding control […] The immediate byte defines several bit fields that control rounding, DAZ, FTZ…
Summary assembled by rule from the sources below