REV

Reverse Bytes reverses the byte order in a register.

This instruction is used by the pseudo-instruction REV64.

313029282726252423222120191817161514131211109876543210
sf10110101100000000001xRnRd
Sopcode2opc

32-bit (sf == 0 && opc == 10)

REV <Wd>, <Wn>

64-bit (sf == 1 && opc == 11)

REV <Xd>, <Xn>

if opc == '11' && sf == '0' then UNDEFINED; integer d = UInt(Rd); integer n = UInt(Rn); constant integer datasize = 32 << UInt(sf); constant integer container_size = 8 << UInt(opc);

Assembler Symbols

<Wd>

Is the 32-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Wn>

Is the 32-bit name of the general-purpose source register, encoded in the "Rn" field.

<Xd>

Is the 64-bit name of the general-purpose destination register, encoded in the "Rd" field.

<Xn>

Is the 64-bit name of the general-purpose source register, encoded in the "Rn" field.

Operation

bits(datasize) operand = X[n, datasize]; bits(datasize) result; constant integer containers = datasize DIV container_size; for c = 0 to containers-1 bits(container_size) container = Elem[operand, c, container_size]; Elem[result, c, container_size] = Reverse(container, 8); X[d, datasize] = result;

Operational information

If PSTATE.DIT is 1:


Internal version only: aarchmrs v2024-03_relA, pseudocode v2024-03_rel, sve v2024-03_rel ; Build timestamp: 2024-03-26T09:45

Copyright © 2010-2024 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.