vrefp

Vector Reciprocal Estimate Floating-Point VX-form

vrefp VRT,VRB

Estimates the reciprocal of single-precision floating-point elements in a vector.

Details

For vrefp, the single-precision floating-point estimate of the reciprocal of each element in VSR[VRB+32] is placed into corresponding elements in VSR[VRT+32].

Pseudocode Operation

if MSR.VEC=0 then
    Vector_Unavailable()
do i = 0 to 3
    src ← VSR[VRB+32].word[i]
    VSR[VRT+32].word[i] ← bfp32_RECIPROCAL_ESTIMATE(src)
end

Programming Note

The vrefp instruction estimates the reciprocal of each single-precision floating-point element in the source vector and stores it in the destination vector. Ensure that the Vector Facility is enabled by checking and setting the VEC bit in the MSR register. This instruction operates on vectors containing 32-bit floating-point numbers, and it does not raise exceptions for invalid operations like division by zero; instead, it returns a NaN or infinity as appropriate.

Example

vrefp v1, v3

Encoding

Binary Layout
4
0
VRT
6
VRB
11
 
Format VX-form
Opcode 0x1000010A
Extension VMX (AltiVec)
Registers Altered MSR

Operands

  • VRT
    Target Vector Register
  • VRB
    Source Vector Register