alt Hacker News> From a bystanderʼs POV it is excessively hard to memorize all the mess with multiple different extensions
It's the same for other ISAs.
> What Iʼm slightly confused for is that all these extensions, useful for a minor part of applications, arenʼt moved to longer instructions (6-byte).
Because these instructions don't need it. There will be future >4-byte instructions, for things thay can't resonably be done in 4-bytes, e.g. much larger immediates.
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wg0 • today at 10:26 AM
> It's the same for other ISAs.
No they are not. See the Intel Software Programmer Volumes. Highly detailed, highly structured and highly specific.
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It's way worse on RISC-V. There are maybe 5 x86 or ARM variants to care about at any given time, even if you want to hyper-optimize your code. RISC-V has a soup of literally 100s of extensions with non-uniform use and support.