[davidkuhta]

> To not leave you hanging: Intel has an official x86 encoder/decoder library called XED. According to Intel’s XED, as of this writing, there are 1503 defined x86 instructions (“iclasses” in XED lingo), from AAA to XTEST (this includes AMD-specific extensions too, by the way). Straightforward, right?

Hopefully this will have either saved you a click or validated your time in reading the article.

[carbonguy]

For me the article was well worth it; where else but in ISA discussions can you find gems like the following?

> Does a non-instruction that is non-defined and unofficially guaranteed to non-execute exactly as if it had never been in the instruction set to begin with count as an x86 instruction? For that matter, does UD2 itself, the defined undefined instruction, count as an instruction?

[sandinmyjoints]

This was why I posted it -- I learned a lot more than the answer to the title.

[anyfoo]

Curious, does anyone actually care about the actual number primarily? I thought pretty much everyone who clicks on an article with that title would do so because they are interested in the insights gathered when getting to that number.

[wglb]

If you are writing a disassembler or binary program decoder, such a number will help you be sure that you enumerate all the instructions.