block/replication: drop extra synchronization

[qemu.git] / util / bitops.c

diff --git a/util/bitops.c b/util/bitops.c
index 9cd1c3a24cc0da667f72385bcb08215a76e8dfc3..f2364015c4bf3933d2f7c6aa2d765f775a8b0e86 100644 (file)
--- a/util/bitops.c
+++ b/util/bitops.c
@@ -11,17 +11,16 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#include "qemu/osdep.h"
 #include "qemu/bitops.h"
 
-#define BITOP_WORD(nr)         ((nr) / BITS_PER_LONG)
-
 /*
  * Find the next set bit in a memory region.
  */
 unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
                            unsigned long offset)
 {
-    const unsigned long *p = addr + BITOP_WORD(offset);
+    const unsigned long *p = addr + BIT_WORD(offset);
     unsigned long result = offset & ~(BITS_PER_LONG-1);
     unsigned long tmp;
 
@@ -42,7 +41,23 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
         size -= BITS_PER_LONG;
         result += BITS_PER_LONG;
     }
-    while (size & ~(BITS_PER_LONG-1)) {
+    while (size >= 4*BITS_PER_LONG) {
+        unsigned long d1, d2, d3;
+        tmp = *p;
+        d1 = *(p+1);
+        d2 = *(p+2);
+        d3 = *(p+3);
+        if (tmp) {
+            goto found_middle;
+        }
+        if (d1 | d2 | d3) {
+            break;
+        }
+        p += 4;
+        result += 4*BITS_PER_LONG;
+        size -= 4*BITS_PER_LONG;
+    }
+    while (size >= BITS_PER_LONG) {
         if ((tmp = *(p++))) {
             goto found_middle;
         }
@@ -70,7 +85,7 @@ found_middle:
 unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
                                 unsigned long offset)
 {
-    const unsigned long *p = addr + BITOP_WORD(offset);
+    const unsigned long *p = addr + BIT_WORD(offset);
     unsigned long result = offset & ~(BITS_PER_LONG-1);
     unsigned long tmp;
 
@@ -109,7 +124,7 @@ found_first:
         return result + size;  /* Nope. */
     }
 found_middle:
-    return result + bitops_ctol(tmp);
+    return result + ctzl(~tmp);
 }
 
 unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
@@ -133,7 +148,7 @@ unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
         tmp = addr[--words];
         if (tmp) {
         found:
-            return words * BITS_PER_LONG + bitops_flsl(tmp);
+            return words * BITS_PER_LONG + BITS_PER_LONG - 1 - clzl(tmp);
         }
     }