CODEWITHSUNDEEP
x86-64cpuinstruction-set
user11224591
user11224591

Reputation:

is x86-64 is just an alias name of EM64T?

I was reading a book which describe a historical perspective:

Pentium 4E (2004, 125 M transistors). Added hyperthreading, a method to run two programs simultaneously on a single processor, as well as EM64T, Intel’s implementation of a 64-bit extension to IA32 developed by Advanced Micro Devices (AMD), which we refer to as x86-64

I'm a little bit confused here,here is my two questions:

Q1-does it mean that x86-64 is just an alias name of EM64T?

Q2- And is IA32 developed by AMD? isn't IA32 designed by Intel and first implemented in the 80386 microprocessor in 1985? https://en.wikipedia.org/wiki/IA-32

Upvotes: 2

Views: 998

Answers (2)

zx485
zx485

Reputation: 29042

AMD first named its (original) 64-bit ISA version x86-64. Intel later named its (mostly compatible) version EMT64. See here at Wayback Machine (Intel):

x64 is a generic name for the 64-bit extensions to Intel's and AMD's 32-bit x86 instruction set architecture (ISA). AMD introduced the first version of x64, initially called x86-64 and later renamed AMD64. Intel named their implementation IA-32e and then EMT64. There are some slight incompatibilities between the two versions, but most code works fine on both versions; details can be found in the Intel® 64 and IA-32 Architectures Software Developer's Manuals and the AMD64 Architecture Tech Docs. We call this intersection flavor x64. Neither is to be confused with the 64-bit Intel® Itanium® architecture, which is called IA-64.

So x64 can be considered standard nowadays.

Relating to your second question: Your assumptions are correct. Intel developed the IA32 ISA and AMD then licensed it with complicated contracts.

Upvotes: 1

Alex Guteniev
Alex Guteniev

Reputation: 13719

Q1. x86-64 is a general name for both Intel's and AMD's implementation. AMD's implementation is also called AMD64, Intel's implementation is also called EMT64.

Q2. Yes. But AMD was the first to make 64-bit implementation of it. Intel's IA64 was different, it was not 64-bit implementation of IA32.

Upvotes: 2

Related Questions