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I did that to write simd routines for sbcl: https://github.com/sbcl/sbcl/blob/master/src/code/arm64-simd... Probably the best way of writing assembly, can evaluate the function imm…

Still 40 years to go.

I have also seen some outright crashes on the new GC.

The tricks to avoid multiplication (and division) are probably worth a whole post. x * 6: lea eax, [rdi+rdi*2] add eax, eax x * 7: lea eax, [0+rdi*8] sub eax, edi x * 11: lea eax, …

The text mentions that it can also do multiplication but doesn't expand on that. E.g. for x * 5 gcc issues lea eax, [rdi+rdi*4].

ABCL is really slow.

A good strategy if you don't care about fixing bugs.

That shouldn't mean that it doesn't return a NaN. Things are generally not optimized away because of NaNs. E.g. in GCC, abs(c) > -1.0 is not folded, unless building with -ffast-mat…

That fix has limited applicability. x * x is also a non-negative float. But abs(x * x) is not optimized. Or abs(abs(x)+1). GCC, for example, does know that.

(+ 2 (id "2")) may also produce a compile time warning. Nothing precludes from having a special rule for that. Like (+ 2 (print "2")) does warn.

> changes in the Qt project made the technique used by the Qt4 bindings impractical for Qt5 or Qt6 - at least that was my understanding when I looked into it. It was hard to do rea…

> Why does SBCL not use LLVM? Why doesn't GCC use LLVM? Why is Zig writing their own backend?

> lack of tail-call elimination But lisp doesn't need TCO.

You can turn them back into rationals, (rational (sqrt 2d0)) => 6369051672525773/4503599627370496 Or write your own operations that compute to the precision you want.

>(safety 0) Please, don't do that!

>any system that relies on information that was typed into a REPL three-months ago and is now only stored in the binary state of that REPL and nowhere else is totally insane as a p…

> roadrunner is petaflops of FP32 Isn't it actually FP64?

Using EAX is one byte shorter, so it might be doing that inadvertently.

Common Lisp. The dynamic-extent declaration allows for stack allocation.

> because 64-bit ARMv8.0 lacks a POPCNT instruction It does have this: https://developer.arm.com/documentation/ddi0596/2021-09/SIMD... And GCC happily uses it https://godbolt.org/z…

There's M-:

CNT on arm64 counts 8 or 16-bit elements too.

SYS:WITHOUT-GCING is better but is still fraught with danger (that's why I didn't mention it).

That's not related to garbage collection.

That's a recipe for disaster. Never do that.