vlogefp

Vector Log Base 2 Estimate Floating-Point

vlogefp VRT,VRB

Estimates the base 2 logarithm of single-precision floating-point elements in a vector register.

Details

For vlogefp, the single-precision floating-point estimate of the base 2 logarithm of each element in VSR[VRB+32] is placed into the corresponding element 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_LOG_BASE2_ESTIMATE(src)
end

Programming Note

This instruction is used for estimating the base 2 logarithm of single-precision floating-point numbers in vector registers. Ensure that the Vector Facility (MSR.VEC) is enabled before using this instruction; otherwise, a Vector_Unavailable exception will be raised. The operation processes four elements at a time, so ensure proper alignment and data handling to avoid unexpected results.

Example

vlogefp v1, v3

Encoding

Binary Layout
0
0
VRT
6
VRB
11
11000000000000000000000000000000
31
 
Format VX-form
Opcode 0x100001CA
Extension VMX (AltiVec)
Registers Altered MSR

Operands

  • VRT
    Target Vector Register
  • VRB
    Source Vector Register