53 lines
1.5 KiB
Diff
53 lines
1.5 KiB
Diff
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From 30150b8727e9ec41f83c4dfcd93f04b766357469 Mon Sep 17 00:00:00 2001
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From: Zhenzhong Duan <zhenzhong.duan@intel.com>
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Date: Wed, 5 Jun 2024 16:30:31 +0800
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Subject: [PATCH] range: Introduce range_get_last_bit()
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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This helper get the highest 1 bit position of the upper bound.
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If the range is empty or upper bound is zero, -1 is returned.
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Suggested-by: Cédric Le Goater <clg@redhat.com>
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Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
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Reviewed-by: Eric Auger <eric.auger@redhat.com>
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Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
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---
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include/qemu/range.h | 11 +++++++++++
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1 file changed, 11 insertions(+)
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diff --git a/include/qemu/range.h b/include/qemu/range.h
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index 205e1da76d..4ce694a398 100644
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--- a/include/qemu/range.h
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+++ b/include/qemu/range.h
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@@ -20,6 +20,8 @@
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#ifndef QEMU_RANGE_H
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#define QEMU_RANGE_H
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+#include "qemu/bitops.h"
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+
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/*
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* Operations on 64 bit address ranges.
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* Notes:
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@@ -217,6 +219,15 @@ static inline int ranges_overlap(uint64_t first1, uint64_t len1,
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return !(last2 < first1 || last1 < first2);
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}
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+/* Get highest non-zero bit position of a range */
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+static inline int range_get_last_bit(Range *range)
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+{
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+ if (range_is_empty(range)) {
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+ return -1;
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+ }
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+ return 63 - clz64(range->upb);
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+}
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+
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/*
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* Return -1 if @a < @b, 1 @a > @b, and 0 if they touch or overlap.
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* Both @a and @b must not be empty.
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--
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2.41.0.windows.1
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