From d44644e6d07e3050ad61864cec5c17c0045e1d47 Mon Sep 17 00:00:00 2001
From: Bill Welliver <bill@welliver.org>
Date: Sun, 7 Dec 2014 19:29:36 +0100
Subject: [PATCH] windows: calculate trailing/leading zeros (more) correctly.
---
src/bitvector.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/src/bitvector.h b/src/bitvector.h
index 3c0ebbbefc..83756fd9a5 100644
--- a/src/bitvector.h
+++ b/src/bitvector.h
@@ -30,7 +30,7 @@ static INLINE unsigned INT32 ATTRIBUTE((unused)) clz32(unsigned INT32 i) {
#elif defined(HAS__BITSCANREVERSE)
unsigned long index;
if (_BitScanReverse(&index, (unsigned long)i))
- return (unsigned INT32)index;
+ return (unsigned INT32)(31 - index);
return 32;
#else
unsigned INT32 t;
@@ -101,7 +101,7 @@ static INLINE unsigned INT32 ATTRIBUTE((unused)) clz64(unsigned INT64 i) {
# elif defined(HAS__BITSCANREVERSE64)
unsigned long index;
if (_BitScanReverse64(&index, i))
- return index;
+ return (63 - index);
return 64;
# else
unsigned INT64 t;
--
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