From c2cbd7ffa71a4009e4cc38c04c726ea562b11361 Mon Sep 17 00:00:00 2001
From: Doug Moore <dougm@FreeBSD.org>
Date: Mon, 31 Jul 2023 21:02:56 -0500
Subject: [PATCH] isa_common: find next bit faster

Since ffs is no longer implemented with a linear search, find_next_bit
can work in constant time, with masking.

Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D41251
---
 sys/isa/isa_common.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/sys/isa/isa_common.c b/sys/isa/isa_common.c
index ca7fd15442b..994288886ce 100644
--- a/sys/isa/isa_common.c
+++ b/sys/isa/isa_common.c
@@ -275,12 +275,7 @@ find_first_bit(uint32_t mask)
 static int
 find_next_bit(uint32_t mask, int bit)
 {
-	bit++;
-	while (bit < 32 && !(mask & (1 << bit)))
-		bit++;
-	if (bit != 32)
-		return (bit);
-	return (-1);
+	return (find_first_bit(mask & (-2 << bit)));
 }
 
 /*