RFC int2string optimisation

[Stephen R. van den Berg]

It seemed like a good idea.

commit beeba499793328cc118992884d8e175caffa6433
Author: Stephen R. van den Berg <[EMAIL PROTECTED]>
Date:   Thu Aug 21 13:17:21 2008 +0200

    Optimise optimisation and move inline int2string
    from roxen.c to operators.c

diff --git a/src/modules/_Roxen/roxen.c b/src/modules/_Roxen/roxen.c
index 253f2b3..dcf6086 100644
--- a/src/modules/_Roxen/roxen.c
+++ b/src/modules/_Roxen/roxen.c
@@ -456,33 +456,6 @@ static void f_html_encode_string( INT32 args )
     void o_cast_to_string();
 
     case PIKE_T_INT:
-      /* Optimization, this is basically a inlined cast_int_to_string */
-      {
-       char buf[21], *b = buf+19;
-       int neg, i, j=0;
-       i = Pike_sp[-1].u.integer;
-       pop_stack();
-       if( i < 0 )
-       {
-         neg = 1;
-         i = -i;
-       }
-       else
-         neg = 0;
-
-       buf[20] = 0;
-
-       while( i >= 10 )
-       {
-         b[ -j++ ] = '0'+(i%10);
-         i /= 10;
-       }
-       b[ -j++ ] = '0'+(i%10);
-       if( neg )  b[ -j++ ] = '-';
-       push_text( b-j+1 );
-      }
-      return;
-
     case PIKE_T_FLOAT:
       /* Optimization, no need to check the resultstring for
        * unsafe characters. 
diff --git a/src/operators.c b/src/operators.c
index 3d12cbd..d1eaf75 100644
--- a/src/operators.c
+++ b/src/operators.c
@@ -343,11 +343,10 @@ PMOD_EXPORT void o_cast_to_int(void)
 /* Special case for casting to string. */
 PMOD_EXPORT void o_cast_to_string(void)
 {
-  char buf[200];
   switch(sp[-1].type)
   {
   case PIKE_T_STRING:
-    return;
+    break;
 
   case T_OBJECT:
     if(!sp[-1].u.object->prog) {
@@ -387,10 +386,40 @@ PMOD_EXPORT void o_cast_to_string(void)
                   get_name_of_type(sp[-1].type));
       }
     }
-    return;
+    break;
            
   case T_INT:
+#if 0
     sprintf(buf, "%"PRINTPIKEINT"d", sp[-1].u.integer);
+#else
+    {
+#define sizeNUM(v)   (8*sizeof(v)*4/10+1+1)
+      INT32 org;
+      char buf[sizeNUM(org)];
+      register char*b = buf+sizeof buf-1;
+      register unsigned i;
+      org = sp[-1].u.integer;
+      pop_stack();
+      *b-- = '\0';
+      i = org;
+
+      if( org < 0 )
+        i = -i;
+
+      goto jin;
+      do {
+        i /= 10;
+jin:    *b-- = '0'+(i%10);
+      }
+      while( i >= 10 );
+
+      if( org<0 )
+       *b = '-';
+      else
+        b++;
+      push_text( b );
+    }
+#endif
     break;
 
   case T_ARRAY:
@@ -462,18 +491,18 @@ PMOD_EXPORT void o_cast_to_string(void)
       pop_stack();
       push_string(s);
     }
-    return;
+    break;
 
-  case T_FLOAT:
+  case T_FLOAT: {
+    char buf[sizeNUM(double)*2];
     sprintf(buf, "%f", (double)sp[-1].u.float_number);
+    push_text(buf);
     break;
+  }
 
   default:
     Pike_error("Cannot cast %s to string.\n", get_name_of_type(sp[-1].type));
   }
-       
-  sp[-1].type = PIKE_T_STRING;
-  sp[-1].u.string = make_shared_string(buf);
 }
 
 PMOD_EXPORT void o_cast(struct pike_type *type, INT32 run_time_type)
-- 
Sincerely,
           Stephen R. van den Berg.
"I was standing in the park wondering why frisbees got bigger
 as they get closer.  Then it hit me."