From: Karl Williamson Date: Sat, 24 Sep 2011 17:29:09 +0000 (-0600) Subject: handy.h: clarify, typos in comment X-Git-Tag: v5.15.4~197 X-Git-Url: https://perl5.git.perl.org/perl5.git/commitdiff_plain/3912bc886c99be4f8599922a1998dcf2cfffe877 handy.h: clarify, typos in comment --- diff --git a/handy.h b/handy.h index 5e30512..3f04b56 100644 --- a/handy.h +++ b/handy.h @@ -562,15 +562,16 @@ patched there. The file as of this writing is cpan/Devel-PPPort/parts/inc/misc */ -/* FITS_IN_8_BITS(c) returns true if c occupies no more than 8 bits. It is - * designed to be hopefully bomb-proof, making sure that no bits of - * information are lost even on a 64-bit machine, but to get the compiler to - * optimize it out if possible. This is because Configure makes sure that the - * machine has an 8-bit byte, so if c is stored in a byte, the sizeof() - * guarantees that this evaluates to a constant true at compile time. The use - * of the mask instead of '< 256' keeps gcc from complaining that it is alway - * true, when c's storage class is a byte. Use U64TYPE because U64 is known - * only in the perl core, and this macro can be called from outside that */ +/* FITS_IN_8_BITS(c) returns true if c doesn't have a bit set other than in + * the lower 8. It is designed to be hopefully bomb-proof, making sure that no + * bits of information are lost even on a 64-bit machine, but to get the + * compiler to optimize it out if possible. This is because Configure makes + * sure that the machine has an 8-bit byte, so if c is stored in a byte, the + * sizeof() guarantees that this evaluates to a constant true at compile time. + * The use of the mask instead of '< 256' keeps gcc from complaining that it is + * always true, when c's storage class is a byte. Use U64TYPE because U64 is + * known only in the perl core, and this macro can be called from outside that + */ #ifdef HAS_QUAD # define FITS_IN_8_BITS(c) ((sizeof(c) == 1) || (((U64TYPE)(c) & 0xFF) == (U64TYPE)(c))) #else