--- a/SmallInteger.st	Wed Mar 27 11:51:54 2002 +0100
+++ b/SmallInteger.st	Thu Mar 28 11:50:28 2002 +0100
@@ -1291,7 +1291,8 @@
 
 lowBit
     "return the bitIndex of the lowest bit set. The returned bitIndex
-     starts at 1 for the least significant bit. Returns -1 if no bit is set."
+     starts at 1 for the least significant bit. 
+     Returns 0 if no bit is set."
 
 %{  /* NOCONTEXT */
 
@@ -1299,88 +1300,86 @@
 
     bits = __intVal(self);
     if (bits == 0) {
-        RETURN ( __MKSMALLINT(-1) );
+        RETURN ( __MKSMALLINT(0) );
     }
 
 #ifdef __BSF
     /*
      * so much for CISC CPUS:
      * the following code is only marginally faster on a PIII-400
-     * (but saves a few code-bytes, though)
+     * (and not at all faster on an Athlon...)
+     * but saves a few code-bytes, though.
      */
     bits = __BSF(bits);
     RETURN ( __MKSMALLINT(bits + 1) );
 #else
 
-    if ((bits & 0xFFFFFF) == 0) {
-        mask = 0x1000000;
-        index = 25;
-    } else {
-        if ((bits & 0xFFFF) == 0) {
-            mask = 0x10000;
-            index = 17;
-        } else {
-            if ((bits & 0xFF) == 0) {
-                mask = 0x100;
-                index = 9;
-            } else {
-                mask = 1;
-                index = 1;
-            }
-        }
-    }
+    index = 1;
 
 # ifdef alpha64
-    while (index != 63) {
-# else
-    while (index != 31) {
+    if ((bits<<32) == 0) {
+        index += 32; bits >>= 32;
+    }
 # endif
-        if (bits & mask) {
-            RETURN ( __MKSMALLINT(index) );
-        }
-        mask = mask << 1;
-        index++;
+
+    if ((bits & 0xFFFF)==0) {
+        index += 16; bits >>= 16;
+    }
+    if ((bits & 0xFF)==0) {
+        index += 8; bits >>= 8;
+    }
+    if ((bits & 0xF)==0) {
+        index += 4; bits >>= 4;
     }
-    RETURN ( __MKSMALLINT(-1) );
+    if ((bits & 0x3)==0) {
+        index += 2; bits >>= 2;
+    }
+    if ((bits & 0x1)==0) {
+        index += 1;
+    }
 #endif
+
+    RETURN ( __MKSMALLINT(index) );
 %}
 
     "
+     0 lowBit            
+     2r0001 lowBit       
+     2r0010 lowBit       
+     2r0100 lowBit       
+     2r1000 lowBit       
+
+     2r000100 lowBit      
+     2r010010 lowBit      
+     2r100001 lowBit      
+     16r1000 lowBit       
+     16r1000000 lowBit    
+     16r1000000000000000 lowBit    
+
      Time millisecondsToRun:[
         1000000 timesRepeat:[
             2r1000 lowBit
         ]
-     ]  
-    "
-    "
+     ]    
+
      Time millisecondsToRun:[
         1000000 timesRepeat:[
             2r11110000000 lowBit
         ]
      ] 
-    "
-    "
+
      Time millisecondsToRun:[
         1000000 timesRepeat:[
             2r1000000000000 lowBit
         ]
      ]  
-    "
-    "
+
      Time millisecondsToRun:[
         1000000 timesRepeat:[
             2r1000000000000000000000000000 lowBit     
         ]
      ]  
     "
-    "
-     2r000100 lowBit
-     2r010010 lowBit
-     2r100001 lowBit
-     16r1000 lowBit 
-     16r1000000 lowBit 
-     0 lowBit 
-    "
 !
 
 setBit:anInteger
@@ -3405,5 +3404,5 @@
 !SmallInteger class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/SmallInteger.st,v 1.145 2002-02-26 10:48:26 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/SmallInteger.st,v 1.146 2002-03-28 10:50:28 cg Exp $'
 ! !