On 4/30/24 11:58, Duan, Zhenzhong wrote:
-----Original Message-----
From: Cédric Le Goater <c...@redhat.com>
Subject: Re: [PATCH v3 06/19] range: Introduce range_get_last_bit()
On 4/29/24 08:50, Zhenzhong Duan wrote:
This helper get the highest 1 bit position of the upper bound.
If the range is empty or upper bound is zero, -1 is returned.
Suggested-by: Cédric Le Goater <c...@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
---
include/qemu/range.h | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/include/qemu/range.h b/include/qemu/range.h
index 205e1da76d..8e05bc1d9f 100644
--- a/include/qemu/range.h
+++ b/include/qemu/range.h
@@ -20,6 +20,8 @@
#ifndef QEMU_RANGE_H
#define QEMU_RANGE_H
+#include "qemu/bitops.h"
+
/*
* Operations on 64 bit address ranges.
* Notes:
@@ -217,6 +219,15 @@ static inline int ranges_overlap(uint64_t first1,
uint64_t len1,
return !(last2 < first1 || last1 < first2);
}
+/* Get highest non-zero bit position of a range */
+static inline int range_get_last_bit(Range *range)
+{
+ if (range_is_empty(range) || !range->upb) {
+ return -1;
+ }
+ return find_last_bit(&range->upb, sizeof(range->upb));
This breaks builds on 32-bit host systems.
Oh, I missed 32bit build. Thanks, will fix.
This should provide the same result ?
return 63 - clz64(range->upb);
Thanks,
C.
