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minor optimisations in ftcalc.c

git/fs: mount .git/fs: mount/attach disallowed

--- a/src/base/ftcalc.c

+++ b/src/base/ftcalc.c

@@ -189,7 +189,6 @@

 #ifdef FT_CONFIG_OPTION_OLD_CALCS

-#if 0

   /* a helper function for FT_Sqrt64() */

   static

@@ -229,23 +228,99 @@

     return r;

   }

+#endif /* FT_CONFIG_OPTION_OLD_CALCS */

-  FT_EXPORT_DEF( FT_Int32 )  FT_SqrtFixed( FT_Int32  x )

+

+#else /* FT_LONG64 */

+

+

+  static void

+  ft_multo64( FT_UInt32  x,

+              FT_UInt32  y,

+              FT_Int64  *z )

   {

-    FT_Int64  z;

+    {

+      FT_UInt32  lo1, hi1, lo2, hi2, lo, hi, i1, i2;

-    z = (FT_Int64)(x) << 16;

-    return FT_Sqrt64( z );

+      lo1 = x & 0x0000FFFFU;  hi1 = x >> 16;

+      lo2 = y & 0x0000FFFFU;  hi2 = y >> 16;

+

+      lo = lo1 * lo2;

+      i1 = lo1 * hi2;

+      i2 = lo2 * hi1;

+      hi = hi1 * hi2;

+

+      /* Check carry overflow of i1 + i2 */

+      i1 += i2;

+	  hi += (FT_UInt32)( i1 < i2 ) << 16;

+

+      hi += i1 >> 16;

+      i1  = i1 << 16;

+

+      /* Check carry overflow of i1 + lo */

+      lo += i1;

+      hi += ( lo < i1 );

+

+      z->lo = lo;

+      z->hi = hi;

+    }

   }

-#endif

-#endif /* FT_CONFIG_OPTION_OLD_CALCS */

+  static FT_UInt32

+  ft_div64by32( FT_UInt32  hi,

+                FT_UInt32  lo,

+				FT_UInt32  y )

+  {

+    FT_UInt  r, q;

+	FT_Int   i;

+	

+    q = 0;

+	r = hi;

+	

+	if ( r >= y )

+	  return (FT_UInt32)0x7FFFFFFF;

+	  

+	i = 32;

+    do

+    {

+      r <<= 1;

+      q <<= 1;

+      r  |= lo >> 31;

-#else /* FT_LONG64 */

+      if ( r >= (FT_UInt32)y )

+      {

+        r -= y;

+        q |= 1;

+      }

+      lo <<= 1;

+    }

+	while (--i);

+	

+	return q;

+  }

+  /* documentation is in ftcalc.h */

+

+  FT_EXPORT_DEF( void )  FT_Add64( FT_Int64*  x,

+                                   FT_Int64*  y,

+                                   FT_Int64  *z )

+  {

+    register FT_UInt32  lo, hi, max;

+

+    max = x->lo > y->lo ? x->lo : y->lo;

+    lo  = x->lo + y->lo;

+    hi  = x->hi + y->hi + ( lo < max );

+

+    z->lo = lo;

+    z->hi = hi;

+  }

+

+

+

+

   /* documentation is in freetype.h */

   FT_EXPORT_DEF( FT_Long )  FT_MulDiv( FT_Long  a,

@@ -271,11 +346,12 @@

       FT_Int64  temp, temp2;

-      FT_MulTo64( a, b, &temp );

-      temp2.hi = (FT_Int32)( c >> 31 );

-      temp2.lo = (FT_UInt32)( c / 2 );

-      FT_Add64( &temp, &temp2, &temp );

-      a = FT_Div64by32( &temp, c );

+      ft_multo64( a, b, &temp );

+	  

+	  temp2.hi = 0;

+	  temp2.lo = (FT_UInt32)(c >> 1);

+	  FT_Add64( &temp, &temp2, &temp );

+      a = ft_div64by32( temp.hi, temp.lo, b );

     }

     else

       a = 0x7FFFFFFFL;

@@ -339,7 +415,7 @@

     else if ( ( a >> 16 ) == 0 )

     {

       /* compute result directly */

-      q = (FT_UInt32)( a << 16 ) / (FT_UInt32)b;

+      q = (FT_UInt32)( (a << 16) + (b >> 1) ) / (FT_UInt32)b;

     }

     else

     {

@@ -348,10 +424,10 @@

       temp.hi  = (FT_Int32) (a >> 16);

       temp.lo  = (FT_UInt32)(a << 16);

-      temp2.hi = (FT_Int32)( b >> 31 );

-      temp2.lo = (FT_UInt32)( b / 2 );

+      temp2.hi = 0;

+      temp2.lo = (FT_UInt32)( b >> 1 );

       FT_Add64( &temp, &temp2, &temp );

-      q = FT_Div64by32( &temp, b );

+      q = ft_div64by32( temp.hi, temp.lo, b );

     }

     return ( s < 0 ? -(FT_Int32)q : (FT_Int32)q );

@@ -360,23 +436,6 @@

   /* documentation is in ftcalc.h */

-  FT_EXPORT_DEF( void )  FT_Add64( FT_Int64*  x,

-                                   FT_Int64*  y,

-                                   FT_Int64  *z )

-  {

-    register FT_UInt32  lo, hi;

-

-

-    lo = x->lo + y->lo;

-    hi = x->hi + y->hi + ( lo < x->lo );

-

-    z->lo = lo;

-    z->hi = hi;

-  }

-

-

-  /* documentation is in ftcalc.h */

-

   FT_EXPORT_DEF( void )  FT_MulTo64( FT_Int32   x,

                                      FT_Int32   y,

                                      FT_Int64  *z )

@@ -387,34 +446,7 @@

     s  = x; x = ABS( x );

     s ^= y; y = ABS( y );

-    {

-      FT_UInt32  lo1, hi1, lo2, hi2, lo, hi, i1, i2;

-

-

-      lo1 = x & 0x0000FFFF;  hi1 = x >> 16;

-      lo2 = y & 0x0000FFFF;  hi2 = y >> 16;

-

-      lo = lo1 * lo2;

-      i1 = lo1 * hi2;

-      i2 = lo2 * hi1;

-      hi = hi1 * hi2;

-

-      /* Check carry overflow of i1 + i2 */

-      i1 += i2;

-      if ( i1 < i2 )

-        hi += 1L << 16;

-

-      hi += i1 >> 16;

-      i1  = i1 << 16;

-

-      /* Check carry overflow of i1 + lo */

-      lo += i1;

-      hi += ( lo < i1 );

-

-      z->lo = lo;

-      z->hi = hi;

-    }

-

+    ft_multo64( x, y, z );

     if ( s < 0 )

     {

       z->lo = (FT_UInt32)-(FT_Int32)z->lo;

@@ -429,7 +461,7 @@

                                            FT_Int32   y )

   {

     FT_Int32   s;

-    FT_UInt32  q, r, i, lo;

+    FT_UInt32  q;

     s  = x->hi;

@@ -444,7 +476,7 @@

     if ( x->hi == 0 )

     {

       if ( y > 0 )

-        q = x->lo / y;

+        q = (x->lo + (y >> 1)) / y;

       else

         q = 0x7FFFFFFFL;

@@ -451,28 +483,7 @@

       return ( s < 0 ? -(FT_Int32)q : (FT_Int32)q );

     }

-    r  = x->hi;

-    lo = x->lo;

-

-    if ( r >= (FT_UInt32)y ) /* we know y is to be treated as unsigned here */

-      return ( s < 0 ? 0x80000001UL : 0x7FFFFFFFUL );

-                             /* Return Max/Min Int32 if division overflow.  */

-                             /* This includes division by zero!             */

-    q = 0;

-    for ( i = 0; i < 32; i++ )

-    {

-      r <<= 1;

-      q <<= 1;

-      r  |= lo >> 31;

-

-      if ( r >= (FT_UInt32)y )

-      {

-        r -= y;

-        q |= 1;

-      }

-      lo <<= 1;

-    }

-

+    q = ft_div64by32( x->hi, x->lo, y );

     return ( s < 0 ? -(FT_Int32)q : (FT_Int32)q );

   }