[range-op] Enable value/mask propagation in range-op.

Throw the switch in range-ops to make full use of the value/mask
information instead of only the nonzero bits.  This will cause most of
the operators implemented in range-ops to use the value/mask
information calculated by CCP's bit_value_binop() function which
range-ops uses.  This opens up more optimization opportunities.

In follow-up patches I will change the global range setter
(set_range_info) to be able to save the value/mask pair, and make both
CCP and IPA be able to save the known ones bit info, instead of
throwing it away.

gcc/ChangeLog:

	* range-op.cc (irange_to_masked_value): Remove.
	(update_known_bitmask): Update irange value/mask pair instead of
	only updating nonzero bits.

gcc/testsuite/ChangeLog:

	* gcc.dg/pr83073.c: Adjust testcase.

2 files changed, 23 insertions, 32 deletions

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index cb58431..56e80c9 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -367,23 +367,6 @@ range_op_handler::op1_op2_relation (const vrange &lhs) const
 }
 
 
-// Convert irange bitmasks into a VALUE MASK pair suitable for calling CCP.
-
-static void
-irange_to_masked_value (const irange &r, widest_int &value, widest_int &mask)
-{
-  if (r.singleton_p ())
-    {
-      mask = 0;
-      value = widest_int::from (r.lower_bound (), TYPE_SIGN (r.type ()));
-    }
-  else
-    {
-      mask = widest_int::from (r.get_nonzero_bits (), TYPE_SIGN (r.type ()));
-      value = 0;
-    }
-}
-
 // Update the known bitmasks in R when applying the operation CODE to
 // LH and RH.
 
@@ -391,25 +374,33 @@ void
 update_known_bitmask (irange &r, tree_code code,
 		      const irange &lh, const irange &rh)
 {
-  if (r.undefined_p () || lh.undefined_p () || rh.undefined_p ())
+  if (r.undefined_p () || lh.undefined_p () || rh.undefined_p ()
+      || r.singleton_p ())
     return;
 
-  widest_int value, mask, lh_mask, rh_mask, lh_value, rh_value;
+  widest_int widest_value, widest_mask;
   tree type = r.type ();
   signop sign = TYPE_SIGN (type);
   int prec = TYPE_PRECISION (type);
-  signop lh_sign = TYPE_SIGN (lh.type ());
-  signop rh_sign = TYPE_SIGN (rh.type ());
-  int lh_prec = TYPE_PRECISION (lh.type ());
-  int rh_prec = TYPE_PRECISION (rh.type ());
-
-  irange_to_masked_value (lh, lh_value, lh_mask);
-  irange_to_masked_value (rh, rh_value, rh_mask);
-  bit_value_binop (code, sign, prec, &value, &mask,
-		   lh_sign, lh_prec, lh_value, lh_mask,
-		   rh_sign, rh_prec, rh_value, rh_mask);
-  wide_int tmp = wide_int::from (value | mask, prec, sign);
-  r.set_nonzero_bits (tmp);
+  irange_bitmask lh_bits = lh.get_bitmask ();
+  irange_bitmask rh_bits = rh.get_bitmask ();
+
+  bit_value_binop (code, sign, prec, &widest_value, &widest_mask,
+		   TYPE_SIGN (lh.type ()),
+		   TYPE_PRECISION (lh.type ()),
+		   widest_int::from (lh_bits.value (), sign),
+		   widest_int::from (lh_bits.mask (), sign),
+		   TYPE_SIGN (rh.type ()),
+		   TYPE_PRECISION (rh.type ()),
+		   widest_int::from (rh_bits.value (), sign),
+		   widest_int::from (rh_bits.mask (), sign));
+
+  wide_int mask = wide_int::from (widest_mask, prec, sign);
+  wide_int value = wide_int::from (widest_value, prec, sign);
+  // Bitmasks must have the unknown value bits cleared.
+  value &= ~mask;
+  irange_bitmask bm (value, mask);
+  r.update_bitmask (bm);
 }
 
 // Return the upper limit for a type.
diff --git a/gcc/testsuite/gcc.dg/pr83073.c b/gcc/testsuite/gcc.dg/pr83073.c
index 1168ae82..228e189 100644
--- a/gcc/testsuite/gcc.dg/pr83073.c
+++ b/gcc/testsuite/gcc.dg/pr83073.c
@@ -7,4 +7,4 @@ int f(int x)
     return x & 1;
 }
 
-/* { dg-final { scan-tree-dump "gimple_simplified to.* = 1" "evrp" } }  */
+/* { dg-final { scan-tree-dump "Folded into: return 1;" "evrp" } }  */