This is a collection of Intel®’ IA32® Software Developer's Manuals (URL of the day) and AMD' AMD64 Architecture Programmer's Manual together with the related specifications, application notes, white papers, and change logs. The collection aims to keep all available revisions. It was originally created by Michal Necasek, see OS/2 Museum.

If you have a public document, related to the IA32® specifications and missing from the collection, please mail it to me. The content of this URL and all sub-ULRs is available for convenient bulk download by rsync x86docs password "" (empty).

SBC -- A64

SBC

Subtract with carry

This instruction subtracts a register value and the value of NOT (Carry flag) from a register value, and writes the result to the destination register.

This instruction is used by the alias NGC.

313029282726252423222120191817161514131211109876543210
sf1011010000Rm000000RnRd
opS

Encoding for the 32-bit variant

Applies when (sf == 0)

SBC <Wd>, <Wn>, <Wm>

Encoding for the 64-bit variant

Applies when (sf == 1)

SBC <Xd>, <Xn>, <Xm>

Decode for all variants of this encoding

let d : integer{} = UInt(Rd); let n : integer{} = UInt(Rn); let m : integer{} = UInt(Rm); let datasize : integer{} = 32 << UInt(sf);

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 first general-purpose source register, encoded in the "Rn" field.

<Wm>

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

<Xm>

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

Alias Conditions

AliasIs preferred when
NGCRn == '11111'

Operation

let operand1 : bits(datasize) = X{}(n); let operand2 : bits(datasize) = NOT(X{datasize}(m)); var result : bits(datasize); (result, -) = AddWithCarry{datasize}(operand1, operand2, PSTATE.C); X{datasize}(d) = result;

Operational information

This instruction is a data-independent-time instruction as described in About PSTATE.DIT.


2026-03_rel 2026-03-26 20:48:11

Copyright © 2010-2026 Arm Limited or its affiliates. All rights reserved. This document is Non-Confidential.