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| -rw-r--r-- | handy.h | 14 |
1 files changed, 14 insertions, 0 deletions
@@ -482,6 +482,20 @@ 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 */ +#ifdef HAS_QUAD +# define FITS_IN_8_BITS(c) ((sizeof(c) == 1) || (((U64)(c) & 0xFF) == (U64)(c))) +#else +# define FITS_IN_8_BITS(c) ((sizeof(c) == 1) || (((U32)(c) & 0xFF) == (U32)(c))) +#endif + #define isALNUM(c) (isALPHA(c) || isDIGIT(c) || (c) == '_') #define isIDFIRST(c) (isALPHA(c) || (c) == '_') #define isALPHA(c) (isUPPER(c) || isLOWER(c)) |