3 ms·
> Outside a core subset of features that programs can assume, you have to check each extension you need before you use it, so (in theory) it should be possible
by wolfgke 9y ago
> Outside a core subset of features that programs can assume, you have to check each extension you need before you use it, so (in theory) it should be possible to drop deadweight extensions in future.
x86 processors also have cpuid
> https://en.wikipedia.org/wiki/CPUID https://en.wikipedia.org/wiki/CPUID
to signal which extensions are supported or not. In theory it would also be possible to drop deadweight extensions this way for x86, too. The practice shows that at least for the tasks that PCs are used for, one can hardly drop anything here. Exceptions are
- 3Dnow! (is not supported in Bulldozer, Bobcat and Zen anymore; cf. https://en.wikipedia.org/w/index.php?title=3DNow!&oldid=769683777#Processors_supporting_3DNow https://en.wikipedia.org/w/index.php?title=3DNow!&oldid=7696...)
- A20 gate (not supported anymore since Haswell: cf. https://en.wikipedia.org/w/index.php?title=A20_line&oldid=781982575#A20_gate https://en.wikipedia.org/w/index.php?title=A20_line&oldid=78...)