diff --git a/src/engine/bsr.h b/src/engine/bsr.h
index 72191f6bd..dcc865112 100644
--- a/src/engine/bsr.h
+++ b/src/engine/bsr.h
@@ -24,7 +24,7 @@
 static inline int bsr(unsigned short v) {
   unsigned long idx;
   if (_BitScanReverse(&idx,(unsigned long)v)) {
-    return idx;
+    return idx+1;
   }
   else {
     return -1;
@@ -34,7 +34,7 @@ static inline int bsr(unsigned short v) {
 static inline int bsr32(unsigned int v) {
   unsigned long idx;
   if (_BitScanReverse(&idx,(unsigned long)v)) {
-    return idx;
+    return idx+1;
   } else {
     return -1;
   }
@@ -62,7 +62,7 @@ static inline int bsr32(unsigned int v) {
 
 static inline int bsr(unsigned short v) {
   unsigned short mask = 0x8000;
-  for (int i = 15; i >= 0; --i) {
+  for (int i = 16; i >= 0; --i) {
     if (v&mask)
       return i;
     mask>>=1;
@@ -73,7 +73,7 @@ static inline int bsr(unsigned short v) {
 
 static inline int bsr32(unsigned int v) {
   unsigned int mask = 0x80000000;
-  for (int i = 31; i >= 0; --i) {
+  for (int i = 32; i >= 0; --i) {
     if (v&mask)
       return i;
     mask>>=1;