fix

Author: kijuky

compiler/src/dotty/tools/dotc/core/TypeComparer.scala

@@ -401,13 +401,7 @@ class TypeComparer(@constructorOnly initctx: Context) extends ConstraintHandling
         compareErasedValueType
       case ConstantType(v2) =>
         tp1 match {
-          case ConstantType(v1) =>
-            (v1.value, v2.value) match {
-              // To distinguish 0.0 and -0.0, floating-point numbers use the equals method of their boxing type.
-              case (d1: Double, d2: Double) => java.lang.Double.valueOf(d1).equals(java.lang.Double.valueOf(d2)) && recur(v1.tpe, v2.tpe)
-              case (f1: Float, f2: Float) => java.lang.Float.valueOf(f1).equals(java.lang.Float.valueOf(f2)) && recur(v1.tpe, v2.tpe)
-              case _ => v1.value == v2.value && recur(v1.tpe, v2.tpe)
-            }
+          case ConstantType(v1) => v1 == v2 && recur(v1.tpe, v2.tpe)
           case _ => secondTry
         }
       case tp2: AnyConstantType =>

tests/neg/i23261.scala

@@ -1,7 +1,7 @@
 @main def main(): Unit =
-  summon[0.0 =:= -0.0]
-  val d: 0.0 = -0.0
-  val d2: -0.0 = 0.0
-  summon[0.0f =:= -0.0f]
-  val f: 0.0f = -0.0f
-  val f2: -0.0f = 0.0f
+  summon[0.0 =:= -0.0]   // error: Cannot prove that (0.0: Double) =:= (-0.0: Double).
+  val d: 0.0 = -0.0      // error: Cannot prove that (0.0: Double) =:= (-0.0: Double).
+  val d2: -0.0 = 0.0     // error: Cannot prove that (-0.0: Double) =:= (0.0: Double).
+  summon[0.0f =:= -0.0f] // error: Cannot prove that (0.0f: Float) =:= (-0.0f: Float).
+  val f: 0.0f = -0.0f    // error: Cannot prove that (0.0f: Float) =:= (-0.0f: Float).
+  val f2: -0.0f = 0.0f   // error: Cannot prove that (-0.0f: Float) =:= (0.0f: Float).