[Debburn-devel] [PATCH] fixes for aliasing bugs

[Albert Cahalan]

On 9/28/06, Peter Samuelson <peter at p12n.org> wrote:
> [Albert Cahalan]

> > a2h[*inp - 192u];
>
> No, that gives the wrong result if *inp is a signed char with a value
> of, say, -15 (that is, 0xf1) - this will yield an array index of -207.
> If that is interpreted as an unsigned value, like a size_t, it becomes
> 4294967089.  Neither is what we want: what we want is 49.  You have to
> cast *inp to unsigned char first, that's just all there is to it.

Rethinking things a bit...

a2h[*inp & 0x3f]