Y86 ISA

Randal E. Bryant
Carnegie Mellon University
CS:APP
CS:APP Chapter 4
Computer Architecture
Instruction Set
Architecture
http://csapp.cs.cmu.edu
Adaptation par J.Bétréma

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Instruction Set Architecture
ISA
Compiler OS
CPU
Design
Circuit
Design
Chip
Layout
Application
Program
Jeu d’instructions du processeur,
ou plutôt du modèle de processeur.

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X86 Evolution: Programmer’s View
Name Date Transistors
8086 1978 29K
16-bit processor. Basis for IBM PC & DOS
Limited to 1MB address space. DOS only gives you 640K
386 1985 275K
Extended to 32 bits. Added “flat addressing”
Capable of running Unix
Linux/gcc uses no instructions introduced in later models
Pentium 1993 3.1M

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X86 Evolution: Programmer’s View
Name Date Transistors
Pentium III 1999 8.2M
Added “streaming SIMD” instructions for operating on 128-bit
vectors of 1, 2, or 4 byte integer or floating point data
Our fish machines
Pentium 4 2001 42M
Added 8-byte formats and 144 new instructions for streaming
SIMD mode

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X86 Evolution: Clones
Advanced Micro Devices (AMD)
Historically
zAMD has followed just behind Intel
zA little bit slower, a lot cheaper
Recently
zRecruited top circuit designers from Digital Equipment Corp.
zExploited fact that Intel distracted by IA64
zNow are close competitors to Intel
Developing own extension to 64 bits