dev/core/test/com/google/gwt/dev/jjs/impl/DeadCodeEliminationTest.java - gwt - Git at Google

 /*
  * Copyright 2008 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License. You may obtain a copy of
  * the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.gwt.dev.jjs.impl;

 import com.google.gwt.dev.jjs.ast.JMethod;
 import com.google.gwt.dev.jjs.ast.JProgram;

 /**
  * Tests {@link DeadCodeElimination}.
  */
 public class DeadCodeEliminationTest extends OptimizerTestBase {
   /*
    * TODO: this class needs more tests, and more sophisticated cases. Especially
    * to ensure we converge in a single pass.
    */

   @Override
   public void setUp() throws Exception {
     addSnippetClassDecl("static volatile boolean b;");
     addSnippetClassDecl("static volatile boolean b1;");
     addSnippetClassDecl("static volatile int i;");
     addSnippetClassDecl("static volatile long l;");
     addSnippetClassDecl("static volatile float f;");
     addSnippetClassDecl("static volatile double d;");
     addSnippetClassDecl("static volatile String s;");
     addSnippetClassDecl("static volatile Object o;");

     runMethodInliner = false;
   }

   public void testConditionalOptimizations() throws Exception {
     optimize("int", "return true ? 3 : 4;").into("return 3;");
     optimize("int", "return false ? 3 : 4;").into("return 4;");

     optimize("boolean", "return b ? true : b1;").into("return b || b1;");
     optimize("boolean", "return b ? false : b1;").into("return !b && b1;");
     optimize("boolean", "return b ? b1 : true;").into("return !b || b1;");
     optimize("boolean", "return b ? b1 : false;").into("return b && b1;");
   }

   public void testIfOptimizations() throws Exception {
     optimize("int", "if (true) return 1; return 0;").into("return 1;");
     optimize("int", "if (false) return 1; return 0;").into("return 0;");
     optimize("int", "if (true) return 1; else return 2;").into("return 1;");
     optimize("int", "if (false) return 1; else return 2;").into("return 2;");

     optimize("int", "if (true) {} else return 4; return 0;").into("return 0;");

     addSnippetClassDecl("static boolean test() { return b; }");
     optimize("int", "if (test()) {} else {}; return 0;").into(
         "test(); return 0;");
   }

   public void testIfStatementToBoolean_NotOptimization() throws Exception {
     optimize("void", "if (!b) i = 1;").intoString(
         "EntryPoint.b || (EntryPoint.i = 1);");
     optimize("void", "if (!b) i = 1; else i = 2;").intoString(
         "EntryPoint.b ? (EntryPoint.i = 2) : (EntryPoint.i = 1);");
     optimize("int", "if (!b) { return 1;} else {return 2;}").into(
         "return b ? 2 : 1;");
   }

   public void testIfStatementToBoolean_ReturnLifting() throws Exception {
     optimize("int", "if (b) return 1; return 2;").into(
         "if (b) return 1; return 2;");
     optimize("int", "if (b) { return 1; }  return 2;").into(
         "if (b) { return 1; } return 2;");
     optimize("int", "if (b) { return 1;} else {return 2;}").into(
         "return b ? 1 : 2;");
     optimize("int", "if (b) return 1; else {return 2;}").into(
         "return b ? 1 : 2;");
     optimize("int", "if (b) return 1; else return 2;").into("return b ? 1 : 2;");
     optimize("void", "if (b) return; else return;").into(
         "if (b) return; else return;");
   }

   public void testIfStatementToBoolean_ThenElseOptimization() throws Exception {
     optimize("void", "if (b) i = 1; else i = 2;").intoString(
         "EntryPoint.b ? (EntryPoint.i = 1) : (EntryPoint.i = 2);");
     optimize("void", "if (b) {i = 1;} else {i = 2;}").intoString(
         "EntryPoint.b ? (EntryPoint.i = 1) : (EntryPoint.i = 2);");
   }

   public void testIfStatementToBoolean_ThenOptimization() throws Exception {
     optimize("void", "if (b) i = 1;").intoString(
         "EntryPoint.b && (EntryPoint.i = 1);");
     optimize("void", "if (b) {i = 1;}").intoString(
         "EntryPoint.b && (EntryPoint.i = 1);");
   }

   /**
    * BUG: JInstance was marked as not having side effects whereas it all depends on the
    * whether the expression on the left has side effects.
    *
    * Reproduces Issue:7818.
    */
   public void testInstanceOfOptimization() throws Exception {
     runMethodInliner = true;
     addSnippetClassDecl(
         "static class A  { "
             + "static int f1;"
             + "static A createA() { A.f1 = 1; return new A(); } "
             + "static boolean instanceofMulti() { return (createA() instanceof A); } "
             + "static boolean inlineable() { instanceofMulti(); return true;}"
             + "}");

     optimizeExpressions(false, "void", "A.inlineable()")
         .into("A.f1 = 1; new A();");
   }


   public void testDoOptimization() throws Exception {
     optimize("void", "do {} while (b);").intoString(
         "do {",
         "} while (EntryPoint.b);");
     optimize("void", "do {} while (true);").intoString(
         "do {",
         "} while (true);");
     optimize("void", "do {} while (false);").intoString("");
     optimize("void", "do { i++; } while (false);").intoString("++EntryPoint.i;");
     optimize("void", "do { break; } while (false);").intoString(
         "do {",
         "  break;",
         "} while (false);");
   }

   public void testMultiExpressionOptimization() throws Exception {
     runMethodInliner = true;
     addSnippetClassDecl(
         "static class A  { ",
         "  static int f;",
         "  static { if (4-f ==0) f=4; }",
         "  static boolean t() { return true; }",
         "  static boolean f() { return false; }",
         "  static boolean notInlineable() { if (4-f == 0) return true;return false;}",
         "}");

     addSnippetClassDecl(
         "static class B  { ",
         "  static boolean inlineableOr() { return A.t() || A.notInlineable(); }",
         "  static boolean inlineableAnd() { return A.t() && A.notInlineable(); }",
         "}");

     optimize("void", "B.inlineableAnd();")
         .intoString("EntryPoint$A.$clinit();\nEntryPoint$A.notInlineable();");
     optimize("void", "B.inlineableOr();")
         .intoString("EntryPoint$A.$clinit();");
   }

   public void testOptimizeStringCalls() throws Exception {
     // Note: we're limited here by the methods declared in the mock String in
     // JJSTestBase#addBuiltinClasses

     // String.length
     optimize("int", "return \"abc\".length();").intoString("return 3;");
     optimize("int", "return s.length();").intoString("return EntryPoint.s.length();");

     // String.charAt
     optimize("char", "return \"abc\".charAt(1);").intoString("return 'b';");
     optimize("char", "return s.charAt(1);").intoString("return EntryPoint.s.charAt(1);");

     // String.toString
     optimize("String", "return s.toString();").intoString("return EntryPoint.s;");
     optimize("String", "return o.toString();").intoString("return EntryPoint.o.toString();");

     // String.hashCode: never optimized
     optimize("int", "return \"abc\".hashCode();").intoString("return \"abc\".hashCode();");
     optimize("int", "return s.hashCode();").intoString("return EntryPoint.s.hashCode();");
   }

   public void testSubtractFromZero() throws Exception {
     optimize("int", "return 0 - i;").intoString("return -EntryPoint.i;");
     optimize("long", "return 0 - l;").intoString("return -EntryPoint.l;");
     // Verify that float/double subtracts from zero aren't replaced, since they
     // are needed for obscure IEEE754 functionality -- specifically, converting
     // 0.0 - v into -v means the sign of the result is the opposite of the input
     // rathe than always being positive.
     optimize("float", "return 0.0F - f;").intoString("return 0.0f - EntryPoint.f;");
     optimize("double", "return 0.0 - d;").intoString("return 0.0 - EntryPoint.d;");
   }

   public void testMultiExpression_RedundantClinitRemoval() throws Exception {
     addSnippetClassDecl(
         "static class A  { "
             + "static int f1;"
             + "static int f2;"
             + "static { f1 = 1; }"
             + "static void m1() { } "
             + "}" +
         "static class B extends A  { "
             + "static int f3;"
             + "static int f4;"
             + "static { f3 = 1; }"
             + "static void m2() { } "
             + "}");

     optimizeExpressions(true, "void", "A.m1()", "A.m1()").intoString("EntryPoint$A.$clinit();\n"
         + "EntryPoint$A.m1();\n"
         + "EntryPoint$A.m1();");
     optimizeExpressions(true, "void", "B.m2()", "A.m1()").intoString("EntryPoint$B.$clinit();\n"
         + "EntryPoint$B.m2();\n"
         + "EntryPoint$A.m1();");
     optimizeExpressions(true, "void", "A.m1()", "B.m2()").intoString("EntryPoint$A.$clinit();\n"
         + "EntryPoint$A.m1();\n"
         + "EntryPoint$B.$clinit();\n"
         + "EntryPoint$B.m2();");
   }

   private boolean runMethodInliner;

   @Override
   protected boolean optimizeMethod(JProgram program, JMethod method) {

     if (runMethodInliner) {
       MethodInliner.exec(program);
     }

     OptimizerStats result = DeadCodeElimination.exec(program, method);
     if (result.didChange()) {
       // Make sure we converge in one pass.
       assertFalse(DeadCodeElimination.exec(program, method).didChange());
     }
     return result.didChange();
   }
 }
	/*
	* Copyright 2008 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License. You may obtain a copy of
	* the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	* License for the specific language governing permissions and limitations under
	* the License.
	*/
	package com.google.gwt.dev.jjs.impl;

	import com.google.gwt.dev.jjs.ast.JMethod;
	import com.google.gwt.dev.jjs.ast.JProgram;

	/**
	* Tests {@link DeadCodeElimination}.
	*/
	public class DeadCodeEliminationTest extends OptimizerTestBase {
	/*
	* TODO: this class needs more tests, and more sophisticated cases. Especially
	* to ensure we converge in a single pass.
	*/

	@Override
	public void setUp() throws Exception {
	addSnippetClassDecl("static volatile boolean b;");
	addSnippetClassDecl("static volatile boolean b1;");
	addSnippetClassDecl("static volatile int i;");
	addSnippetClassDecl("static volatile long l;");
	addSnippetClassDecl("static volatile float f;");
	addSnippetClassDecl("static volatile double d;");
	addSnippetClassDecl("static volatile String s;");
	addSnippetClassDecl("static volatile Object o;");

	runMethodInliner = false;
	}

	public void testConditionalOptimizations() throws Exception {
	optimize("int", "return true ? 3 : 4;").into("return 3;");
	optimize("int", "return false ? 3 : 4;").into("return 4;");

	optimize("boolean", "return b ? true : b1;").into("return b \|\| b1;");
	optimize("boolean", "return b ? false : b1;").into("return !b && b1;");
	optimize("boolean", "return b ? b1 : true;").into("return !b \|\| b1;");
	optimize("boolean", "return b ? b1 : false;").into("return b && b1;");
	}

	public void testIfOptimizations() throws Exception {
	optimize("int", "if (true) return 1; return 0;").into("return 1;");
	optimize("int", "if (false) return 1; return 0;").into("return 0;");
	optimize("int", "if (true) return 1; else return 2;").into("return 1;");
	optimize("int", "if (false) return 1; else return 2;").into("return 2;");

	optimize("int", "if (true) {} else return 4; return 0;").into("return 0;");

	addSnippetClassDecl("static boolean test() { return b; }");
	optimize("int", "if (test()) {} else {}; return 0;").into(
	"test(); return 0;");
	}

	public void testIfStatementToBoolean_NotOptimization() throws Exception {
	optimize("void", "if (!b) i = 1;").intoString(
	"EntryPoint.b \|\| (EntryPoint.i = 1);");
	optimize("void", "if (!b) i = 1; else i = 2;").intoString(
	"EntryPoint.b ? (EntryPoint.i = 2) : (EntryPoint.i = 1);");
	optimize("int", "if (!b) { return 1;} else {return 2;}").into(
	"return b ? 2 : 1;");
	}

	public void testIfStatementToBoolean_ReturnLifting() throws Exception {
	optimize("int", "if (b) return 1; return 2;").into(
	"if (b) return 1; return 2;");
	optimize("int", "if (b) { return 1; } return 2;").into(
	"if (b) { return 1; } return 2;");
	optimize("int", "if (b) { return 1;} else {return 2;}").into(
	"return b ? 1 : 2;");
	optimize("int", "if (b) return 1; else {return 2;}").into(
	"return b ? 1 : 2;");
	optimize("int", "if (b) return 1; else return 2;").into("return b ? 1 : 2;");
	optimize("void", "if (b) return; else return;").into(
	"if (b) return; else return;");
	}

	public void testIfStatementToBoolean_ThenElseOptimization() throws Exception {
	optimize("void", "if (b) i = 1; else i = 2;").intoString(
	"EntryPoint.b ? (EntryPoint.i = 1) : (EntryPoint.i = 2);");
	optimize("void", "if (b) {i = 1;} else {i = 2;}").intoString(
	"EntryPoint.b ? (EntryPoint.i = 1) : (EntryPoint.i = 2);");
	}

	public void testIfStatementToBoolean_ThenOptimization() throws Exception {
	optimize("void", "if (b) i = 1;").intoString(
	"EntryPoint.b && (EntryPoint.i = 1);");
	optimize("void", "if (b) {i = 1;}").intoString(
	"EntryPoint.b && (EntryPoint.i = 1);");
	}

	/**
	* BUG: JInstance was marked as not having side effects whereas it all depends on the
	* whether the expression on the left has side effects.
	*
	* Reproduces Issue:7818.
	*/
	public void testInstanceOfOptimization() throws Exception {
	runMethodInliner = true;
	addSnippetClassDecl(
	"static class A { "
	+ "static int f1;"
	+ "static A createA() { A.f1 = 1; return new A(); } "
	+ "static boolean instanceofMulti() { return (createA() instanceof A); } "
	+ "static boolean inlineable() { instanceofMulti(); return true;}"
	+ "}");

	optimizeExpressions(false, "void", "A.inlineable()")
	.into("A.f1 = 1; new A();");
	}


	public void testDoOptimization() throws Exception {
	optimize("void", "do {} while (b);").intoString(
	"do {",
	"} while (EntryPoint.b);");
	optimize("void", "do {} while (true);").intoString(
	"do {",
	"} while (true);");
	optimize("void", "do {} while (false);").intoString("");
	optimize("void", "do { i++; } while (false);").intoString("++EntryPoint.i;");
	optimize("void", "do { break; } while (false);").intoString(
	"do {",
	" break;",
	"} while (false);");
	}

	public void testMultiExpressionOptimization() throws Exception {
	runMethodInliner = true;
	addSnippetClassDecl(
	"static class A { ",
	" static int f;",
	" static { if (4-f ==0) f=4; }",
	" static boolean t() { return true; }",
	" static boolean f() { return false; }",
	" static boolean notInlineable() { if (4-f == 0) return true;return false;}",
	"}");

	addSnippetClassDecl(
	"static class B { ",
	" static boolean inlineableOr() { return A.t() \|\| A.notInlineable(); }",
	" static boolean inlineableAnd() { return A.t() && A.notInlineable(); }",
	"}");

	optimize("void", "B.inlineableAnd();")
	.intoString("EntryPoint$A.$clinit();\nEntryPoint$A.notInlineable();");
	optimize("void", "B.inlineableOr();")
	.intoString("EntryPoint$A.$clinit();");
	}

	public void testOptimizeStringCalls() throws Exception {
	// Note: we're limited here by the methods declared in the mock String in
	// JJSTestBase#addBuiltinClasses

	// String.length
	optimize("int", "return \"abc\".length();").intoString("return 3;");
	optimize("int", "return s.length();").intoString("return EntryPoint.s.length();");

	// String.charAt
	optimize("char", "return \"abc\".charAt(1);").intoString("return 'b';");
	optimize("char", "return s.charAt(1);").intoString("return EntryPoint.s.charAt(1);");

	// String.toString
	optimize("String", "return s.toString();").intoString("return EntryPoint.s;");
	optimize("String", "return o.toString();").intoString("return EntryPoint.o.toString();");

	// String.hashCode: never optimized
	optimize("int", "return \"abc\".hashCode();").intoString("return \"abc\".hashCode();");
	optimize("int", "return s.hashCode();").intoString("return EntryPoint.s.hashCode();");
	}

	public void testSubtractFromZero() throws Exception {
	optimize("int", "return 0 - i;").intoString("return -EntryPoint.i;");
	optimize("long", "return 0 - l;").intoString("return -EntryPoint.l;");
	// Verify that float/double subtracts from zero aren't replaced, since they
	// are needed for obscure IEEE754 functionality -- specifically, converting
	// 0.0 - v into -v means the sign of the result is the opposite of the input
	// rathe than always being positive.
	optimize("float", "return 0.0F - f;").intoString("return 0.0f - EntryPoint.f;");
	optimize("double", "return 0.0 - d;").intoString("return 0.0 - EntryPoint.d;");
	}

	public void testMultiExpression_RedundantClinitRemoval() throws Exception {
	addSnippetClassDecl(
	"static class A { "
	+ "static int f1;"
	+ "static int f2;"
	+ "static { f1 = 1; }"
	+ "static void m1() { } "
	+ "}" +
	"static class B extends A { "
	+ "static int f3;"
	+ "static int f4;"
	+ "static { f3 = 1; }"
	+ "static void m2() { } "
	+ "}");

	optimizeExpressions(true, "void", "A.m1()", "A.m1()").intoString("EntryPoint$A.$clinit();\n"
	+ "EntryPoint$A.m1();\n"
	+ "EntryPoint$A.m1();");
	optimizeExpressions(true, "void", "B.m2()", "A.m1()").intoString("EntryPoint$B.$clinit();\n"
	+ "EntryPoint$B.m2();\n"
	+ "EntryPoint$A.m1();");
	optimizeExpressions(true, "void", "A.m1()", "B.m2()").intoString("EntryPoint$A.$clinit();\n"
	+ "EntryPoint$A.m1();\n"
	+ "EntryPoint$B.$clinit();\n"
	+ "EntryPoint$B.m2();");
	}

	private boolean runMethodInliner;

	@Override
	protected boolean optimizeMethod(JProgram program, JMethod method) {

	if (runMethodInliner) {
	MethodInliner.exec(program);
	}

	OptimizerStats result = DeadCodeElimination.exec(program, method);
	if (result.didChange()) {
	// Make sure we converge in one pass.
	assertFalse(DeadCodeElimination.exec(program, method).didChange());
	}
	return result.didChange();
	}
	}