Improve performance of getting this variable in methods.

Author: dim-s

jphp-core/src/org/develnext/jphp/core/compiler/jvm/statement/ClassStmtCompiler.java

@@ -382,6 +382,14 @@ protected void writeConstructor() {
                     false
             ));
 
+            LabelNode label = expressionCompiler.writeLabel(methodCompiler.node);
+            LocalVariable local = methodCompiler.addLocalVariable("$THIS", label, Memory.class);
+            expressionCompiler.writeDefineThis(local, null);
+
+            expressionCompiler.writeVarLoad("~this");
+            expressionCompiler.writeVarLoad("$THIS");
+            expressionCompiler.writePutDynamic("$THIS", Memory.class);
+
             // PROPERTIES
             for (ClassVarStmtToken property : statement.getProperties()) {
                 ExpressionStmtCompiler expressionStmtCompiler = new ExpressionStmtCompiler(methodCompiler, null);
@@ -487,6 +495,13 @@ protected void writeConstant(ConstStmtToken constant) {
 
     @SuppressWarnings("unchecked")
     protected void writeSystemInfo() {
+        node.fields.add(new FieldNode(
+                ACC_PUBLIC, "$THIS",
+                Type.getDescriptor(Memory.class),
+                null,
+                null
+        ));
+
         node.fields.add(new FieldNode(
                 ACC_PUBLIC + ACC_FINAL + ACC_STATIC, "$FN",
                 Type.getDescriptor(String.class),

jphp-core/src/org/develnext/jphp/core/compiler/jvm/statement/ExpressionStmtCompiler.java

@@ -1467,18 +1467,24 @@ public void writePushThis() {
             writeVarLoad("~this");
             writeGetDynamic("self", Memory.class);
         } else {
-            if (method.getLocalVariable("this") == null) {
-                if (!methodStatement.isStatic()) {
+            if (!methodStatement.isStatic()) {
+                if (method.getLocalVariable("this") == null) {
                     LabelNode label = writeLabel(node);
                     LocalVariable local = method.addLocalVariable("this", label, Memory.class);
-                    writeDefineThis(local, null);
-                } else {
-                    writePushNull();
-                    return;
+
+                    if (method.clazz.entity.isTrait()) { // if trait we need get this dynamically
+                        writeDefineThis(local, null);
+                    } else { // in normal case, get by this
+                        writeVarLoad("~this");
+                        writeGetDynamic("$THIS", Memory.class);
+                        writeVarStore(local, false, false);
+                    }
                 }
-            }
 
-            writeVarLoad("this");
+                writeVarLoad("this");
+            } else {
+                writePushNull();
+            }
         }
     }