PR tree-optimization/96818 - cast label range to type of switch operand

PR tree-optimization/96818
	* tree-vrp.c (find_case_label_range): Cast label range to
	type of switch operand.

gcc/testsuite/g++.dg/pr96818.C

@@ -0,0 +1,28 @@
+// { dg-do compile }
+// { dg-options "-O2" }
+
+bool operatorY ();
+
+struct l
+{
+  int m;
+  int k;
+  void n ();
+    l ()
+  {
+    while (operatorY ())
+      switch ((unsigned char) k)
+	case 0:
+	{
+	  n ();
+	  case 1:if (m)
+	    ;
+	}
+  }
+};
+
+void
+p ()
+{
+  l ();
+}

gcc/testsuite/gcc.dg/pr96818.c

@@ -0,0 +1,14 @@
+// { dg-do compile }
+// { dg-options "-O2" }
+
+int a, b, c;
+void d() {
+  unsigned short e;
+  while (b)
+    ;
+  e = (e + 5) / a;
+  switch (e)
+  case 0:
+  case 3:
+    c = a;
+}

gcc/tree-vrp.c

@@ -3850,6 +3850,8 @@ find_case_label_range (gswitch *switch_stmt, const irange *range_of_op)
       if (!case_high)
 	case_high = CASE_LOW (max_label);
       widest_irange label_range (CASE_LOW (min_label), case_high);
+      if (!types_compatible_p (label_range.type (), range_of_op->type ()))
+	range_cast (label_range, range_of_op->type ());
       label_range.intersect (range_of_op);
       if (label_range.undefined_p ())
 	return gimple_switch_label (switch_stmt, 0);