GNU Info

(nasm.info)Section B.4.220

---

Next: Section B.4.221 Prev: Section B.4.219 Up: Section B.4

---

Enter node , (file) or (file)node

B.4.220. `PFRCP': Packed Single-Precision FP Reciprocal Approximation
---------------------------------------------------------------------

     PFRCP mm1,mm2/m64             ; 0F 0F /r 96          [PENT,3DNOW]

   `PFRCP' performs a low precision estimate of the reciprocal of the
low-order single-precision FP value in the source operand, storing the
result in both halves of the destination register. The result is
accurate to 14 bits.

   For higher precision reciprocals, this instruction should be
followed by two more instructions: `PFRCPIT1' (*Note Section B.4.221::)
and `PFRCPIT2' (*Note Section B.4.221::). This will result in a 24-bit
accuracy. For more details, see the AMD 3DNow! technology manual.