diff options
| -rw-r--r-- | src/opt.c | 26 |
1 files changed, 17 insertions, 9 deletions
@@ -2176,17 +2176,20 @@ static struct bfs_expr *optimize(struct bfs_opt *opt, struct bfs_expr *expr) { return expr; } -/** Estimate the odds of an expression calling stat(). */ -static float expr_stat_odds(struct bfs_expr *expr) { - if (expr->calls_stat) { +/** An expression predicate. */ +typedef bool expr_pred(const struct bfs_expr *expr); + +/** Estimate the odds that a matching expression will be evaluated. */ +static float estimate_odds(const struct bfs_expr *expr, expr_pred *pred) { + if (pred(expr)) { return 1.0; } - float nostat_odds = 1.0; + float nonmatch_odds = 1.0; float reached_odds = 1.0; for_expr (child, expr) { - float child_odds = expr_stat_odds(child); - nostat_odds *= 1.0 - reached_odds * child_odds; + float child_odds = estimate_odds(child, pred); + nonmatch_odds *= 1.0 - reached_odds * child_odds; if (expr->eval_fn == eval_and) { reached_odds *= child->probability; @@ -2195,7 +2198,12 @@ static float expr_stat_odds(struct bfs_expr *expr) { } } - return 1.0 - nostat_odds; + return 1.0 - nonmatch_odds; +} + +/** Whether an expression calls stat(). */ +static bool calls_stat(const struct bfs_expr *expr) { + return expr->calls_stat; } /** Estimate the odds of calling stat(). */ @@ -2204,10 +2212,10 @@ static float estimate_stat_odds(struct bfs_ctx *ctx) { return 1.0; } - float nostat_odds = 1.0 - expr_stat_odds(ctx->exclude); + float nostat_odds = 1.0 - estimate_odds(ctx->exclude, calls_stat); float reached_odds = 1.0 - ctx->exclude->probability; - float expr_odds = expr_stat_odds(ctx->expr); + float expr_odds = estimate_odds(ctx->expr, calls_stat); nostat_odds *= 1.0 - reached_odds * expr_odds; return 1.0 - nostat_odds; |