commit 0f93cd67bd9598d4cf86656a3fcf191a86fbd89b
author Ian Zerny <zerny@google.com> Tue May 28 10:54:02 2019 +0200
committer Morten Krogh-Jespersen <mkroghj@google.com> Tue May 28 09:33:28 2019 +0000
tree defaf3239440eaecac84469f30f7232da07e7c2b
parent ae9daae88d5a2f6e8c2826d6c07a2b661d8158d2

Make type evaluation of checkcast invariant except for nullability info.

The check cast provides a static contract for the verification of code, so the
type should reflect exactly the check cast type. The check-cast removal
optimizations could and should remove or refine the instruction.

Change-Id: I7e50e15b2fab66d95520d8a6454eb93536156267

src/main/java/com/android/tools/r8/ir/analysis/type/BottomTypeLatticeElement.java

diff --git a/src/main/java/com/android/tools/r8/ir/analysis/type/BottomTypeLatticeElement.java b/src/main/java/com/android/tools/r8/ir/analysis/type/BottomTypeLatticeElement.java
index 6d95d82..b57753e 100644
--- a/src/main/java/com/android/tools/r8/ir/analysis/type/BottomTypeLatticeElement.java
+++ b/src/main/java/com/android/tools/r8/ir/analysis/type/BottomTypeLatticeElement.java
@@ -3,9 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 package com.android.tools.r8.ir.analysis.type;
 
-import com.android.tools.r8.graph.AppView;
-import com.android.tools.r8.graph.DexType;
-
 public class BottomTypeLatticeElement extends TypeLatticeElement {
   private static final BottomTypeLatticeElement INSTANCE = new BottomTypeLatticeElement();
 
@@ -24,11 +21,6 @@
   }
 
   @Override
-  public TypeLatticeElement checkCast(AppView<?> appView, DexType castType) {
-    return this;
-  }
-
-  @Override
   public String toString() {
     return "BOTTOM (empty)";
   }

src/main/java/com/android/tools/r8/ir/analysis/type/TopTypeLatticeElement.java

diff --git a/src/main/java/com/android/tools/r8/ir/analysis/type/TopTypeLatticeElement.java b/src/main/java/com/android/tools/r8/ir/analysis/type/TopTypeLatticeElement.java
index 15774bb..1d483e8 100644
--- a/src/main/java/com/android/tools/r8/ir/analysis/type/TopTypeLatticeElement.java
+++ b/src/main/java/com/android/tools/r8/ir/analysis/type/TopTypeLatticeElement.java
@@ -3,9 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 package com.android.tools.r8.ir.analysis.type;
 
-import com.android.tools.r8.graph.AppView;
-import com.android.tools.r8.graph.DexType;
-
 public class TopTypeLatticeElement extends TypeLatticeElement {
   private static final TopTypeLatticeElement INSTANCE = new TopTypeLatticeElement();
 
@@ -24,11 +21,6 @@
   }
 
   @Override
-  public TypeLatticeElement checkCast(AppView<?> appView, DexType castType) {
-    return this;
-  }
-
-  @Override
   public String toString() {
     return "TOP (everything)";
   }

src/main/java/com/android/tools/r8/ir/analysis/type/TypeLatticeElement.java

diff --git a/src/main/java/com/android/tools/r8/ir/analysis/type/TypeLatticeElement.java b/src/main/java/com/android/tools/r8/ir/analysis/type/TypeLatticeElement.java
index e12d780..94cd5e1 100644
--- a/src/main/java/com/android/tools/r8/ir/analysis/type/TypeLatticeElement.java
+++ b/src/main/java/com/android/tools/r8/ir/analysis/type/TypeLatticeElement.java
@@ -367,14 +367,6 @@
         || (isWide() && other.isWide());
   }
 
-  public TypeLatticeElement checkCast(AppView<?> appView, DexType castType) {
-    TypeLatticeElement castTypeLattice = fromDexType(castType, nullability(), appView);
-    if (lessThanOrEqual(castTypeLattice, appView)) {
-      return this;
-    }
-    return castTypeLattice;
-  }
-
   @Override
   public abstract String toString();
 

src/main/java/com/android/tools/r8/ir/code/CheckCast.java

diff --git a/src/main/java/com/android/tools/r8/ir/code/CheckCast.java b/src/main/java/com/android/tools/r8/ir/code/CheckCast.java
index 354b82d..6804745 100644
--- a/src/main/java/com/android/tools/r8/ir/code/CheckCast.java
+++ b/src/main/java/com/android/tools/r8/ir/code/CheckCast.java
@@ -111,7 +111,7 @@
 
   @Override
   public TypeLatticeElement evaluate(AppView<?> appView) {
-    return object().getTypeLattice().checkCast(appView, type);
+    return TypeLatticeElement.fromDexType(type, object().getTypeLattice().nullability(), appView);
   }
 
   @Override