Difference between amd64 and Intel64 assembly

Programming x86-64 Assembly
1

#I’m confused by these two dialects

I am starting out with assembly and whenever I look around for the manual I am met with the two, what I don’t understand is that, intel had launched it’s Intel64 design but it was not well adopted, amd released their own and were met by huge success so the name stuck with them. But when I search for Intel64 manual, since my laptop is powered by an intel chip I get results saying intel 64 IA-32. Thanks for anyone who’ll clarify this, I’ve been trying to wrap my head around it but I just end up scratching it instead.

2

My understanding is both Intel and AMD CPUs can run the x86-64 instruction set. For most intents and purposes, consider them both built to the same standard.

3

There is no universal x86 specification, and the architecture has two major vendors, each with its own manual and implementation.

IA-32 is the 32-bit x86 architecture, created by Intel and then followed by AMD.

AMD64 is the 64-bit extension of the same architecture created by AMD and then followed by Intel in Intel 64.

Almost everything in AMD64 and Intel 64 is equivalent. One vendor usually creates something that the other clones or reimplements, if it is well accepted.

For the purposes of this track and the vast majority of user-level programs, you can consider them the same architecture.

4

That refers to the Itanium design that isn’t isn’t in your laptop.

Back in 1985, Intel launched the 80386 chip and the IA-32 instruction set.

Other companies like AMD also sold chips using the same instruction set.

With 32 bit pointers, each process running on the chip can access at most 4GB of memory. Some of this space is reserved by operating systems, so in practice each process could access 2GB or 3GB.

Some other companies, like Sun, sold 64 bit chips that didn’t have this limitation. This was irrelevant for consumer hardware, but for servers running large databases, it was a huge advantage.

Then in 2001, Intel (with HP) introduced the Itanium chip with a completely new instruction set called IA-64. It never sold well.

Instead of using the completely new IA-64 instruction set, AMD designed a way to extend the existing IA-32 instruction set to support 64 bits. This design was initially known as amd64, and is now usually called x86-64, with AMD and Intel both using it. This is what your laptop uses.