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hush: optimize #[#] and %[%] for speed. size -2 bytes.

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Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
This commit is contained in:
Denys Vlasenko
2010-09-04 21:21:07 +02:00
parent e298ce69ba
commit 701e127f7d
3 changed files with 89 additions and 72 deletions
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29
shell/match.h
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@@ -7,25 +7,26 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
//TODO! Why ash.c still uses internal version?!
typedef char *(*scan_t)(char *string, char *match, bool match_at_left);
enum {
SCAN_MOVE_FROM_LEFT = (1 << 0),
SCAN_MOVE_FROM_RIGHT = (1 << 1),
SCAN_MATCH_LEFT_HALF = (1 << 2),
SCAN_MATCH_RIGHT_HALF = (1 << 3),
};
char *scanleft(char *string, char *match, bool match_at_left);
char *scanright(char *string, char *match, bool match_at_left);
char* FAST_FUNC scan_and_match(char *string, const char *pattern, unsigned flags);
static inline scan_t pick_scan(char op1, char op2, bool *match_at_left)
static inline unsigned pick_scan(char op1, char op2)
{
/* # - scanleft
* ## - scanright
* % - scanright
* %% - scanleft
*/
unsigned scan_flags;
if (op1 == '#') {
*match_at_left = true;
return op1 == op2 ? scanright : scanleft;
} else {
*match_at_left = false;
return op1 == op2 ? scanleft : scanright;
scan_flags = SCAN_MATCH_LEFT_HALF +
(op1 == op2 ? SCAN_MOVE_FROM_RIGHT : SCAN_MOVE_FROM_LEFT);
} else { /* % */
scan_flags = SCAN_MATCH_RIGHT_HALF +
(op1 == op2 ? SCAN_MOVE_FROM_LEFT : SCAN_MOVE_FROM_RIGHT);
}
return scan_flags;
}
POP_SAVED_FUNCTION_VISIBILITY