Devirtualize Type.exists

OlivierBlanvillain · OlivierBlanvillain · commit f25a60f34a0a · 2018-03-08T11:23:59.000+01:00
diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala
@@ -97,7 +97,7 @@ object Types {
     }
 
     /** Is this type different from NoType? */
-    def exists: Boolean = true
+    final def exists: Boolean = !this.eq(NoType)
 
     /** This type, if it exists, otherwise `that` type */
     def orElse(that: => Type) = if (exists) this else that
@@ -3741,7 +3741,6 @@ object Types {
 
   /** Sentinel for "missing type" */
   @sharable case object NoType extends CachedGroundType {
-    override def exists = false
     override def computeHash(bs: Binders) = hashSeed
   }
 

Original file line number	Diff line number	Diff line change
`@@ -97,7 +97,7 @@ object Types {`
`97`	`97`	`}`
`98`	`98`
`99`	`99`	`/** Is this type different from NoType? */`
`100`		`- def exists: Boolean = true`
	`100`	`+ final def exists: Boolean = !this.eq(NoType)`
`101`	`101`
`102`	`102`	/** This type, if it exists, otherwise `that` type */
`103`	`103`	`def orElse(that: => Type) = if (exists) this else that`
`@@ -3741,7 +3741,6 @@ object Types {`
`3741`	`3741`
`3742`	`3742`	`/** Sentinel for "missing type" */`
`3743`	`3743`	`@sharable case object NoType extends CachedGroundType {`
`3744`		`- override def exists = false`
`3745`	`3744`	`override def computeHash(bs: Binders) = hashSeed`
`3746`	`3745`	`}`
`3747`	`3746`