[PATCH 1/5] grep: micro-optimize hit collection for AND nodes
- From
René Scharfe <rene.scharfe@lsrfire.ath.cx>
- Date
- Mar 7, 2009, 12:27 UTC
- Message-ID
- <1236428835.6486.43.camel@ubuntu.ubuntu-domain>
- In-Reply-To
- <1236428699.6486.41.camel@ubuntu.ubuntu-domain>
In addition to returning if an expression matches a line, match_expr_eval() updates the expression's hit flag if the parameter collect_hits is set. It never sets collect_hits for children of AND nodes, though, so their hit flag will never be updated. Because of that we can return early if the first child didn't match, no matter if collect_hits is set or not.
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> --- grep.c | 10 +++------- 1 files changed, 3 insertions(+), 7 deletions(-)
diff --git a/grep.c b/grep.c index 062b2b6..db341b6 100644 --- a/grep.c +++ b/grep.c @@ -394,13 +394,9 @@ static int match_expr_eval(struct grep_opt *o, h = !match_expr_eval(o, x->u.unary, bol, eol, ctx, 0); break; case GREP_NODE_AND: - if (!collect_hits) - return (match_expr_eval(o, x->u.binary.left, - bol, eol, ctx, 0) && - match_expr_eval(o, x->u.binary.right, - bol, eol, ctx, 0)); - h = match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0); - h &= match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 0); + if (!match_expr_eval(o, x->u.binary.left, bol, eol, ctx, 0)) + return 0; + h = match_expr_eval(o, x->u.binary.right, bol, eol, ctx, 0); break; case GREP_NODE_OR: if (!collect_hits)
-- 1.6.2