double-int.h (double_int_sub): Declare.

2010-07-05  Richard Guenther  <rguenther@suse.de>

	* double-int.h (double_int_sub): Declare.
	* double-int.c (double_int_sub): New function.
	* dwarf2out.c (field_byte_offset): Use it.
	* fixed-value.c (do_fixed_add): Likewise.
	(do_fixed_multiply): Likewise.
	(do_fixed_divide): Likewise.
	* tree-predcom.c (add_ref_to_chain): Likewise.
	(determine_roots_comp): Likewise.
	* tree-ssa-loop-niter.c (derive_constant_upper_bound_ops): Likewise.

From-SVN: r161835

gcc/double-int.c

@@ -792,6 +792,17 @@ double_int_add (double_int a, double_int b)
   return ret;
 }
 
+/* Returns A - B.  */
+
+double_int
+double_int_sub (double_int a, double_int b)
+{
+  double_int ret;
+  neg_double (b.low, b.high, &b.low, &b.high);
+  add_double (a.low, a.high, b.low, b.high, &ret.low, &ret.high);
+  return ret;
+}
+
 /* Returns -A.  */
 
 double_int

gcc/double-int.h

@@ -133,6 +133,7 @@ double_int_fits_in_uhwi_p (double_int cst)
 
 double_int double_int_mul (double_int, double_int);
 double_int double_int_add (double_int, double_int);
+double_int double_int_sub (double_int, double_int);
 double_int double_int_neg (double_int);
 
 /* You must ensure that double_int_ext is called on the operands

gcc/dwarf2out.c

@@ -15745,7 +15745,7 @@ field_byte_offset (const_tree decl)
 	 where the lowest addressed bit of the containing object must
 	 be.  */
       object_offset_in_bits
-	= double_int_add (deepest_bitpos, double_int_neg (type_size_in_bits));
+	= double_int_sub (deepest_bitpos, type_size_in_bits);
 
       /* Round up to type_align by default.  This works best for
 	 bitfields.  */
@@ -15755,8 +15755,7 @@ field_byte_offset (const_tree decl)
       if (double_int_ucmp (object_offset_in_bits, bitpos_int) > 0)
 	{
 	  object_offset_in_bits
-	    = double_int_add (deepest_bitpos,
+	    = double_int_sub (deepest_bitpos, type_size_in_bits);
-			      double_int_neg (type_size_in_bits));
 
 	  /* Round up to decl_align instead.  */
 	  object_offset_in_bits

gcc/fixed-value.c

@@ -361,7 +361,7 @@ do_fixed_add (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
 		  double_int one;
 		  one.low = 1;
 		  one.high = 0;
-		  f->data = double_int_add (f->data, double_int_neg (one));
+		  f->data = double_int_sub (f->data, one);
 		}
 	    }
 	  else
@@ -443,12 +443,12 @@ do_fixed_multiply (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
       temp1.high = 0;
       r = double_int_add (r, temp1);
 
-      /* We need to add neg(b) to r, if a < 0.  */
+      /* We need to subtract b from r, if a < 0.  */
       if (!unsigned_p && a->data.high < 0)
-	r = double_int_add (r, double_int_neg (b->data));
+	r = double_int_sub (r, b->data);
-      /* We need to add neg(a) to r, if b < 0.  */
+      /* We need to subtract a from r, if b < 0.  */
       if (!unsigned_p && b->data.high < 0)
-	r = double_int_add (r, double_int_neg (a->data));
+	r = double_int_sub (r, a->data);
 
       /* Shift right the result by FBIT.  */
       if (GET_MODE_FBIT (f->mode) == 2 * HOST_BITS_PER_WIDE_INT)
@@ -588,7 +588,7 @@ do_fixed_divide (FIXED_VALUE_TYPE *f, const FIXED_VALUE_TYPE *a,
 			 &quo_s.low, &quo_s.high, 0);
 
 	  /* Try to calculate (mod - pos_b).  */
-	  temp = double_int_add (mod, double_int_neg (pos_b));
+	  temp = double_int_sub (mod, pos_b);
 
 	  if (leftmost_mod == 1 || double_int_cmp (mod, pos_b, 1) != -1)
 	    {

gcc/tree-predcom.c

@@ -925,7 +925,7 @@ add_ref_to_chain (chain_p chain, dref ref)
   double_int dist;
 
   gcc_assert (double_int_scmp (root->offset, ref->offset) <= 0);
-  dist = double_int_add (ref->offset, double_int_neg (root->offset));
+  dist = double_int_sub (ref->offset, root->offset);
   if (double_int_ucmp (uhwi_to_double_int (MAX_DISTANCE), dist) <= 0)
     {
       free (ref);
@@ -1199,8 +1199,7 @@ determine_roots_comp (struct loop *loop,
     {
       if (!chain || !DR_IS_READ (a->ref)
 	  || double_int_ucmp (uhwi_to_double_int (MAX_DISTANCE),
-			      double_int_add (a->offset,
+			      double_int_sub (a->offset, last_ofs)) <= 0)
-					      double_int_neg (last_ofs))) <= 0)
 	{
 	  if (nontrivial_chain_p (chain))
 	    {

gcc/tree-ssa-loop-niter.c

@@ -2397,7 +2397,7 @@ derive_constant_upper_bound_ops (tree type, tree op0,
 	  /* OP0 + CST.  We need to check that
 	     BND <= MAX (type) - CST.  */
 
-	  mmax = double_int_add (max, double_int_neg (cst));
+	  mmax = double_int_sub (max, cst);
 	  if (double_int_ucmp (bnd, mmax) > 0)
 	    return max;
 
@@ -2429,7 +2429,7 @@ derive_constant_upper_bound_ops (tree type, tree op0,
 		return max;
 	    }
 
-	  bnd = double_int_add (bnd, double_int_neg (cst));
+	  bnd = double_int_sub (bnd, cst);
 	}
 
       return bnd;