diff options
Diffstat (limited to 'src/lisp.h')
| -rw-r--r-- | src/lisp.h | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/src/lisp.h b/src/lisp.h index 6003daee8fa..4dfed319490 100644 --- a/src/lisp.h +++ b/src/lisp.h @@ -911,8 +911,18 @@ struct Lisp_Vector #endif /* not __GNUC__ */ +/* Compute A OP B, using the unsigned comparison operator OP. A and B + should be integer expressions. This is not the same as + mathemeatical comparison; for example, UNSIGNED_CMP (0, <, -1) + returns 1. For efficiency, prefer plain unsigned comparison if A + and B's sizes both fit (after integer promotion). */ +#define UNSIGNED_CMP(a, op, b) \ + (max (sizeof ((a) + 0), sizeof ((b) + 0)) <= sizeof (unsigned) \ + ? ((a) + (unsigned) 0) op ((b) + (unsigned) 0) \ + : ((a) + (uintmax_t) 0) op ((b) + (uintmax_t) 0)) + /* Nonzero iff C is an ASCII character. */ -#define ASCII_CHAR_P(c) ((unsigned) (c) < 0x80) +#define ASCII_CHAR_P(c) UNSIGNED_CMP (c, <, 0x80) /* Almost equivalent to Faref (CT, IDX) with optimization for ASCII characters. Do not check validity of CT. */ |