From 8605bd9321010f15c471d511de5a06bbd9cc7c4b Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <aldyh@redhat.com>
Date: Wed, 26 Jul 2023 11:00:08 +0200
Subject: [PATCH] [range-ops] Remove special case for handling bitmasks in
 casts.

Now that we can generically handle bitmasks for unary operators,
there's no need to special case them.

gcc/ChangeLog:

	* range-op-mixed.h (class operator_cast): Add update_bitmask.
	* range-op.cc (operator_cast::update_bitmask): New.
	(operator_cast::fold_range): Call update_bitmask.
---
 gcc/range-op-mixed.h |  2 ++
 gcc/range-op.cc      | 23 ++++++++---------------
 2 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/gcc/range-op-mixed.h b/gcc/range-op-mixed.h
index 70550c52232..3cb904f9d80 100644
--- a/gcc/range-op-mixed.h
+++ b/gcc/range-op-mixed.h
@@ -346,6 +346,8 @@ public:
   relation_kind lhs_op1_relation (const irange &lhs,
 				  const irange &op1, const irange &op2,
 				  relation_kind) const final override;
+  void update_bitmask (irange &r, const irange &lh,
+		       const irange &rh) const final override;
 private:
   bool truncating_cast_p (const irange &inner, const irange &outer) const;
   bool inside_domain_p (const wide_int &min, const wide_int &max,
diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index 5653ca0d186..615e5fe0036 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -2881,24 +2881,17 @@ operator_cast::fold_range (irange &r, tree type ATTRIBUTE_UNUSED,
 	return true;
     }
 
-  // Update the bitmask.  Truncating casts are problematic unless
-  // the conversion fits in the resulting outer type.
-  irange_bitmask bm = inner.get_bitmask ();
-  if (truncating_cast_p (inner, outer)
-      && wi::rshift (bm.mask (),
-		     wi::uhwi (TYPE_PRECISION (outer.type ()),
-			       TYPE_PRECISION (inner.type ())),
-		     TYPE_SIGN (inner.type ())) != 0)
-    return true;
-  unsigned prec = TYPE_PRECISION (type);
-  signop sign = TYPE_SIGN (inner.type ());
-  bm = irange_bitmask (wide_int::from (bm.value (), prec, sign),
-		       wide_int::from (bm.mask (), prec, sign));
-  r.update_bitmask (bm);
-
+  update_bitmask (r, inner, outer);
   return true;
 }
 
+void
+operator_cast::update_bitmask (irange &r, const irange &lh,
+			       const irange &rh) const
+{
+  update_known_bitmask (r, CONVERT_EXPR, lh, rh);
+}
+
 bool
 operator_cast::op1_range (irange &r, tree type,
 			  const irange &lhs,