[gcc r14-255] Fix swapping of ranges.

[Aldy Hernandez <aldyh@gcc.gnu.org>]

https://gcc.gnu.org/g:04e5ddf8a313e85348a05c27708c845cc45e2e83

commit r14-255-g04e5ddf8a313e85348a05c27708c845cc45e2e83
Author: Aldy Hernandez <aldyh@redhat.com>
Date:   Wed Dec 21 19:26:00 2022 +0100

    Fix swapping of ranges.
    
    The legacy range code has logic to swap out of order endpoints in the
    irange constructor.  The new irange code expects the caller to fix any
    inconsistencies, thus speeding up the common case.  However, this means
    that when we remove legacy, any stragglers must be fixed.  This patch
    fixes the 3 culprits found during the conversion.
    
    gcc/ChangeLog:
    
            * range-op.cc (operator_cast::op1_range): Use
            create_possibly_reversed_range.
            (operator_bitwise_and::simple_op1_range_solver): Same.
            * value-range.cc (swap_out_of_order_endpoints): Delete.
            (irange::set): Remove call to swap_out_of_order_endpoints.

Diff:
---
 gcc/range-op.cc    | 10 ++++++----
 gcc/value-range.cc | 47 -----------------------------------------------
 2 files changed, 6 insertions(+), 51 deletions(-)

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index f90e78dcfbc..e47edcf3d74 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -2876,8 +2876,9 @@ operator_cast::op1_range (irange &r, tree type,
 	  // Start by building the positive signed outer range for the type.
 	  wide_int lim = wi::set_bit_in_zero (TYPE_PRECISION (lhs_type),
 					      TYPE_PRECISION (type));
-	  r = int_range<1> (type, lim, wi::max_value (TYPE_PRECISION (type),
-						      SIGNED));
+	  create_possibly_reversed_range (r, type, lim,
+					  wi::max_value (TYPE_PRECISION (type),
+							 SIGNED));
 	  // For the signed part, we need to simply union the 2 ranges now.
 	  r.union_ (converted_lhs);
 
@@ -3367,7 +3368,7 @@ operator_bitwise_and::simple_op1_range_solver (irange &r, tree type,
   if (we_know_nothing)
     r.set_varying (type);
   else
-    r = int_range<1> (type, minv, maxv);
+    create_possibly_reversed_range (r, type, minv, maxv);
 
   // Solve [-INF, lhs.upper_bound ()] = x & MASK.
   //
@@ -3398,7 +3399,8 @@ operator_bitwise_and::simple_op1_range_solver (irange &r, tree type,
     }
   maxv |= ~cst2v;
   minv = sgnbit;
-  int_range<1> upper_bits (type, minv, maxv);
+  int_range<2> upper_bits;
+  create_possibly_reversed_range (upper_bits, type, minv, maxv);
   r.intersect (upper_bits);
 }
 
diff --git a/gcc/value-range.cc b/gcc/value-range.cc
index a50d1a63968..da9098139ad 100644
--- a/gcc/value-range.cc
+++ b/gcc/value-range.cc
@@ -1014,46 +1014,6 @@ irange::copy_to_legacy (const irange &src)
     set (src.tree_lower_bound (), src.tree_upper_bound ());
 }
 
-// Swap MIN/MAX if they are out of order and adjust KIND appropriately.
-
-static void
-swap_out_of_order_endpoints (tree &min, tree &max, value_range_kind &kind)
-{
-  gcc_checking_assert (kind != VR_UNDEFINED);
-  if (kind == VR_VARYING)
-    return;
-  /* Wrong order for min and max, to swap them and the VR type we need
-     to adjust them.  */
-  if (tree_int_cst_lt (max, min))
-    {
-      tree one, tmp;
-
-      /* For one bit precision if max < min, then the swapped
-	 range covers all values, so for VR_RANGE it is varying and
-	 for VR_ANTI_RANGE empty range, so drop to varying as well.  */
-      if (TYPE_PRECISION (TREE_TYPE (min)) == 1)
-	{
-	  kind = VR_VARYING;
-	  return;
-	}
-
-      one = build_int_cst (TREE_TYPE (min), 1);
-      tmp = int_const_binop (PLUS_EXPR, max, one);
-      max = int_const_binop (MINUS_EXPR, min, one);
-      min = tmp;
-
-      /* There's one corner case, if we had [C+1, C] before we now have
-	 that again.  But this represents an empty value range, so drop
-	 to varying in this case.  */
-      if (tree_int_cst_lt (max, min))
-	{
-	  kind = VR_VARYING;
-	  return;
-	}
-      kind = kind == VR_RANGE ? VR_ANTI_RANGE : VR_RANGE;
-    }
-}
-
 void
 irange::irange_set (tree min, tree max)
 {
@@ -1192,13 +1152,6 @@ irange::set (tree min, tree max, value_range_kind kind)
   gcc_checking_assert (TREE_CODE (min) == INTEGER_CST
 		       && TREE_CODE (max) == INTEGER_CST);
 
-  swap_out_of_order_endpoints (min, max, kind);
-  if (kind == VR_VARYING)
-    {
-      set_varying (TREE_TYPE (min));
-      return;
-    }
-
   // Anti-ranges that can be represented as ranges should be so.
   if (kind == VR_ANTI_RANGE)
     {