git: 996fa9fb4ec4 - main - kern/rman: update rman_make_alignment_flags()

The branch main has been updated by imp:

URL: https://cgit.FreeBSD.org/src/commit/?id=996fa9fb4ec47995e89d2089e6084d37dcb1033c

commit 996fa9fb4ec47995e89d2089e6084d37dcb1033c
Author:     Elliott Mitchell <ehem+freebsd@m5p.com>
AuthorDate: 2024-05-09 04:47:09 +0000
Commit:     Warner Losh <imp@FreeBSD.org>
CommitDate: 2024-05-21 23:52:27 +0000

    kern/rman: update rman_make_alignment_flags()
    
    The flsl() function makes use of hardware functionality to compute the
    value faster than this loop.  The only deviation from flsl() is at 0.
    
    Reviewed by: imp,jhb
    Pull Request: https://github.com/freebsd/freebsd-src/pull/1224
---
 sys/kern/subr_rman.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/sys/kern/subr_rman.c b/sys/kern/subr_rman.c
index 2019e19090c0..508152f74002 100644
--- a/sys/kern/subr_rman.c
+++ b/sys/kern/subr_rman.c
@@ -776,19 +776,14 @@ rman_release_resource(struct resource *re)
 uint32_t
 rman_make_alignment_flags(uint32_t size)
 {
-	int i;
 
 	/*
 	 * Find the hightest bit set, and add one if more than one bit
 	 * set.  We're effectively computing the ceil(log2(size)) here.
 	 */
-	for (i = 31; i > 0; i--)
-		if ((1 << i) & size)
-			break;
-	if (~(1 << i) & size)
-		i++;
-
-	return(RF_ALIGNMENT_LOG2(i));
+	if (__predict_false(size == 0))
+		return (0);
+	return (RF_ALIGNMENT_LOG2(flsl(size - 1)));
 }
 
 rman_res_t