> Presumably because it doesn't matter that much, so it isn't worth the investment for Intel.
Intel invested in a new instruction set (IA64). AMD did not.
The market chose AMD's offering.
And the market also chose ARM's AArch64 instruction set, despite the ARM installed base being wider than x86 and a backwards incompatible break from the past. The secret? Supporting both ISAs and switching instruction sets on exceptions.
The lesson I take from history is that there is no need to maintain ISA compatibility as long as the old mode is accessible on a process level.
Re:X86 Register Encoding
by imtringued on Wednesday November 02, 2016 @03:34AM
(#12852892)
>The secret? Supporting both ISAs and switching instruction sets on exceptions.
The secret is that Apple controls their hardware/appstore and android apps are ISA independent.
Re:X86 Register Encoding
by adrianratnapala on Wednesday November 02, 2016 @06:16AM
(#12853392)
Whot?
Didn't the AMD64 architecture spank Itanium in the marketplace long before the iPhone became a big deal?
Presumably because it doesn't matter that much, so it isn't worth the investment for Intel.
It feels to me like people have trouble accepting that both of these are true: (1) RISC vs. x86 doesn't matter that much in practice; (2) technically speaking, RISC is a superior design to x86.