Re: libpng-1.5.6rc01 is available

I think for p=0 and x=0 this:

#define S_COPY(p,x) (((p)<4 ? 0x80088822 >> ((3-(p))*8+(7-(x))) :\
            0xaa55ff00 >> ((7-(p))*8+(7-(x)))) & 1)

evaluates into

(((0)<4 ? 0x80088822 >> 31 : 0xaa55ff00 >> 63) & 1)

and then it complains about 63 being too big.