From 931f63d47845139791ef6d28d2795df7e71e13f9 Mon Sep 17 00:00:00 2001
From: Antti Kantee <pooka@iki.fi>
Date: Tue, 3 Nov 2015 18:17:08 +0000
Subject: [PATCH] pgalloc: use builtin_ctz/clz instead of for loops.

---
 lib/libbmk_core/pgalloc.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/lib/libbmk_core/pgalloc.c b/lib/libbmk_core/pgalloc.c
index ceb61c3..8c2d5db 100644
--- a/lib/libbmk_core/pgalloc.c
+++ b/lib/libbmk_core/pgalloc.c
@@ -276,16 +276,19 @@ static void
 carverange(unsigned long addr, unsigned long range)
 {
 	struct chunk *ch;
-	unsigned i;
+	unsigned i, r;
 
 	while (range) {
 		/*
 		 * Next chunk is limited by alignment of addr, but also
 		 * must not be bigger than remaining range.
 		 */
-		for (i = 0; order2size(i+1) <= range; i++)
-			if (addr & order2size(i))
-				break;
+		i = __builtin_ctzl(addr);
+		r = 8*sizeof(range) - (__builtin_clzl(range)+1);
+		if (i > r) {
+			i = r;
+		}
+		i -= BMK_PCPU_PAGE_SHIFT;
 
 		ch = addr2chunk(addr, 0);
 		carveandlink_freechunk(ch, i);
-- 
2.39.5