ISA_v83A_A64_xml_00bet6.1 (old) | htmldiff from-ISA_v83A_A64_xml_00bet6.1 | (new) ISA_v84A_A64_xml_00bet7 |
Compare (extended register) subtracts a sign or zero-extended register value, followed by an optional left shift amount, from a register value. The argument that is extended from the <Rm> register can be a byte, halfword, word, or doubleword. It updates the condition flags based on the result, and discards the result.
This is an alias of SUBS (extended register). This means:
31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
sf | 1 | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 0 | 1 | Rm | option | imm3 | Rn | 1 | 1 | 1 | 1 | 1 | ||||||||||||
op | S | Rd |
CMP <Wn|WSP>, <Wm>{, <extend> {#<amount>}}
is equivalent to
SUBS WZR, <Wn|WSP>, <Wm>{, <extend> {#<amount>}}
and is always the preferred disassembly.
CMP <Xn|SP>, <R><m>{, <extend> {#<amount>}}
is equivalent to
SUBS XZR, <Xn|SP>, <R><m>{, <extend> {#<amount>}}
and is always the preferred disassembly.
<Wn|WSP> | Is the 32-bit name of the first source general-purpose register or stack pointer, encoded in the "Rn" field. |
<Wm> | Is the 32-bit name of the second general-purpose source register, encoded in the "Rm" field. |
<Xn|SP> | Is the 64-bit name of the first source general-purpose register or stack pointer, encoded in the "Rn" field. |
<R> |
option:
|
<m> | Is the number [0-30] of the second general-purpose source register or the name ZR (31), encoded in the "Rm" field. |
<extend> |
option:
| ||||||||||||||||||||||||||||||||||||
option:
|
The description of SUBS (extended register) gives the operational pseudocode for this instruction.
If PSTATE.DIT is 1:
Internal version only: isa v29.05v27.02, AdvSIMD v26.0, pseudocode v35.3v34.2.2
; Build timestamp: 2018-06-16T092018-03-28T19:4555
Copyright © 2010-2018 ARM Limited or its affiliates. All rights reserved. This document is Non-Confidential.
ISA_v83A_A64_xml_00bet6.1 (old) | htmldiff from-ISA_v83A_A64_xml_00bet6.1 | (new) ISA_v84A_A64_xml_00bet7 |