Nios II Classic Processor Reference Guide

ID 683620
Date 10/28/2016
Public
Document Table of Contents

8.5.21. cmpeq

Instruction compare equal
Operation

if (rA == rB)

then rC ←  1

else rC ←  0

Assembler Syntax

cmpeq rC, rA, rB

Example

cmpeq r6, r7, r8

Description

If rA == rB, then stores 1 to rC; otherwise, stores 0 to rC.

Usage

cmpeq performs the == operation of the C programming language. Also, cmpeq can be used to implement the C logical negation operator “!”.

cmpeq rC, rA, r0

# Implements rC = !rA

Exceptions

None

Instruction Type

R

Instruction Fields

A = Register index of operand rA

B = Register index of operand rB

C = Register index of operand rC

Bit Fields
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
A B C 0x20
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0x20 0 0x3a