[libc] Optimize swab so that it can handle any ssize_t value

[gfunni234_gmail.com]

Summary

Casting to int cuts off data on some platforms for some sizes, resulting in the incorrect results for swab.

[jrtc27]

lib/libc/string/swab.c

51

1 works fine, it trivially ends up doing nothing. 0 does also, but that doesn't matter, the point is you don't need to touch this line.

53–55

So just make n a ssize_t or a size_t (since negative len gets an early return)? Please learn to make your changes minimal, not change the whole thing just because you feel like it.

[gfunni234_gmail.com]

lib/libc/string/swab.c

53–55

I thought less was more but ok.

[jrtc27]

lib/libc/string/swab.c

53–55

Yes. Change less.

[gfunni234_gmail.com]

Addressed issues!

[jrtc27]

lib/libc/string/swab.c

51

Don't mark this as done if you haven't done it

[jrtc27]

lib/libc/string/swab.c

51

Changing len < 2 to len <= 1 has no effect and is clearly therefore not what I meant. I meant remove the unnecessary change entirely.

[gfunni234_gmail.com]

Addressed!

[gfunni234_gmail.com]

lib/libc/string/swab.c

51

Addressed!

[gfunni234_gmail.com]

@jrtc27 this good?

[gfunni234_gmail.com]

@imp any updates?