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| author | Paul Eggert <eggert@cs.ucla.edu> | 2017-07-05 17:51:31 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2017-07-05 18:59:31 -0700 |
| commit | d6662694d05be03fdd070353637dd22a324c8b7a (patch) | |
| tree | 3823cc192290478c041db63121c88afebfccbc13 /src/character.h | |
| parent | 24faf6b0d2fe990e9334dd2e3238f749fec87897 (diff) | |
| download | emacs-d6662694d05be03fdd070353637dd22a324c8b7a.tar.gz | |
Convert hex digits more systematically
This makes the code a bit smaller and presumably faster, as
it substitutes a single lookup for conditional jumps.
* src/character.c (hexdigit): New constant.
(syms_of_character) [HEXDIGIT_IS_CONST]: Initialize it.
* src/character.h (HEXDIGIT_CONST, HEXDIGIT_IS_CONST): New macros.
(hexdigit): New decl.
(char_hexdigit): New inline function.
* src/charset.c: Do not include c-ctype.h.
* src/charset.c (read_hex):
* src/editfns.c (styled_format):
* src/image.c (xbm_scan):
* src/lread.c (read_escape):
* src/regex.c (ISXDIGIT) [emacs]:
Use char_hexdigit insted of doing it by hand.
Diffstat (limited to 'src/character.h')
| -rw-r--r-- | src/character.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/src/character.h b/src/character.h index 62d252e91ba..b073a0dd1e4 100644 --- a/src/character.h +++ b/src/character.h @@ -700,6 +700,24 @@ char_table_translate (Lisp_Object obj, int ch) return CHARACTERP (obj) ? XINT (obj) : ch; } +#if defined __GNUC__ && !defined __STRICT_ANSI__ +# define HEXDIGIT_CONST const +# define HEXDIGIT_IS_CONST true +#else +# define HEXDIGIT_CONST +# define HEXDIGIT_IS_CONST false +#endif +extern signed char HEXDIGIT_CONST hexdigit[]; + +/* If C is a hexadecimal digit ('0'-'9', 'a'-'f', 'A'-'F'), return its + value (0-15). Otherwise return -1. */ + +INLINE int +char_hexdigit (int c) +{ + return 0 <= c && c <= UCHAR_MAX ? hexdigit[c] : -1; +} + INLINE_HEADER_END #endif /* EMACS_CHARACTER_H */ |