Re: [Ocaml-lib-devel] second proposal of UChar, UTF8 modules

[Nicolas C. <war...@fr...>]

> > let add_uchar buf u =
> >   let masq = 0b111111 in
> >   let k = int_of_uchar u in
> >   if k < 0 || k >= 0x4000000 then begin
> >     Buffer.add_char buf (Char.chr (0xfc + (k lsr 30)));
> >     Buffer.add_char buf (Char.unsafe_chr (0x80 lor ((k lsr 24) land
masq)));
>
> You might try replacing 'masq' with the actual literal value,
> though the compiler should be able to determine its a constant,
> it may not.

I'm pretty sure it is doing it.
Since masq is non-mutable, this is an easy optimisation for the compiler.
BTW, you can check the native output code by running ocamlopt with -S

> The other thing to do here is reorder the tests:
> test k>=0 && k<=07f first, then k<=07ff ..., reason being
> that the first case is 99.99% of cases. The second
> is 99.99% of the rest of cases.

This one the compiler can't :-)

Nicolas Cannasse