Re:Intel x86 documentation has more pages than the 6502 has ...
by Someone on Wednesday December 07, 2016 @06:18PM
(#13127121)
Lots of it isn't so much bad design as not willing to give up backwards compatibility. Some examples:
- the old floating point register stack and its 80-bit registers
- I don't know how many iterations on SIMD instructions (MMX, a few iterations of SSE, a few iterations of AVX, various prefixes to make older instructions use newer registers)
If you got rid of those, you also could get rid of quite a few prefix instructions, maybe a configuration bit here and there, etc.
It also doesn't help that, at times, Intel and AMD independently added stuff to the x86.
- the old floating point register stack and its 80-bit registers
- I don't know how many iterations on SIMD instructions (MMX, a few iterations of SSE, a few iterations of AVX, various prefixes to make older instructions use newer registers)
If you got rid of those, you also could get rid of quite a few prefix instructions, maybe a configuration bit here and there, etc.
It also doesn't help that, at times, Intel and AMD independently added stuff to the x86.