vminub

Vector Minimum Unsigned Byte

vminub vD, vA, vB

Selects minimum value per byte (unsigned).

Encoding

Binary Layout

0:5

6:10

11:15

16:20

1026

21:31

Format VA-form

Opcode 0x10000202

Extension VMX (AltiVec)

Operands

vD
Target
vA
Src A
vB
Src B

Example

vminub vd, va, vb

Registers Altered

MSR

Reference

View in PowerISA v3.1C Specification ↗ OPF Power ISA v3.1C

Description

Selects the minimum unsigned value for each corresponding byte pair from vA and vB, storing the results in vD. This is a vector operation that performs 16 independent byte-wise minimum comparisons in parallel. No condition flags or status fields are affected.

Operation

for i in 0 to 15 do
  vD[8*i:8*i+7] ← MIN_UNSIGNED(vA[8*i:8*i+7], vB[8*i:8*i+7])
end for

Programming Note

The vminub instruction is used to perform element-wise minimum comparison of unsigned bytes between two vector registers and store the results in a third register. Ensure that the Vector Facility (MSR.VEC) is enabled before using this instruction; otherwise, a Vector_Unavailable exception will be raised. The operation is straightforward but requires both source vectors to be properly aligned for optimal performance.