Title: Theory / Unimportant / CS / Hardware / Intel / manual{ / Instructions
Tags: fromMath mathToDef mathToSee

-Prefixes
-Opcode
-ModR/M
-SIB,
-Displacement,
-Immediate.
Page: 1
Chapter: 2A 2
Name: Instruction format

Name: LOCK prefix
Definition: Forces an operation that ensures exclusive use of shared memory in a multiprocessor environment
Page: 1
Chapter: 2A 2
Section: 1.1
Notation: F0H

Name: Repeat prefix
Definition: Cause an instruction to be repeated for each element of a string.
Page: 1
Chapter: 2A 2
Section: 1.1
Notation: F2H F3H
Assuming: Use these prefixes only with string and I/O instructions (MOVS, CMPS, SCAS, LODS, STOS, INS, and OUTS)

Name: Branch hint prefix
Definition: Allow a program to give a hint to the processor about the most likely code path for a branch.
Page: 1
Chapter: 2A 2
Section: 1.1
Notation: 2EH, 3EH
Assuming: Use these prefixes only with conditional branch instructions (Jcc)

Name: Operand-size override prefix
Definition: Use 16 or 32-bit operand size, the non-default one.
Page: 1
Chapter: 2A 2
Section: 1.1
Notation: 67H

Name: Instuction prefix
Definition: At most one element from each of the four group, in any order.
Page: 1
Chapter: 2A 2
Section: 1.1

Name: Opcode
Definition: Define the direction of operation, size of displacements, register encoding, condition codes, or sign extension.
Page: 1
Chapter: 2A 2
Section: 1.2