small optimizaton of toString for primitive types (no boxing needed)

compiler/backend/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -48,6 +48,7 @@ import org.jetbrains.jet.lang.resolve.BindingContextUtils;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
 import org.jetbrains.jet.lang.resolve.calls.*;
 import org.jetbrains.jet.lang.resolve.constants.CompileTimeConstant;
+import org.jetbrains.jet.lang.resolve.java.AsmTypeConstants;
 import org.jetbrains.jet.lang.resolve.java.JvmAbi;
 import org.jetbrains.jet.lang.resolve.java.JvmClassName;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.*;
@@ -998,7 +999,7 @@ public class ExpressionCodegen extends JetVisitor<StackValue, StackValue> implem
                 }
             }
             v.invokevirtual("java/lang/StringBuilder", "toString", "()Ljava/lang/String;");
-            return StackValue.onStack(expressionType(expression));
+            return StackValue.onStack(AsmTypeConstants.JAVA_STRING_TYPE);
         }
     }
 

compiler/backend/src/org/jetbrains/jet/codegen/intrinsics/ToString.java

@@ -20,11 +20,11 @@ import com.intellij.psi.PsiElement;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.asm4.Type;
 import org.jetbrains.asm4.commons.InstructionAdapter;
-import org.jetbrains.jet.lang.resolve.java.AsmTypeConstants;
 import org.jetbrains.jet.codegen.ExpressionCodegen;
 import org.jetbrains.jet.codegen.StackValue;
 import org.jetbrains.jet.codegen.state.GenerationState;
 import org.jetbrains.jet.lang.psi.JetExpression;
+import org.jetbrains.jet.lang.resolve.java.AsmTypeConstants;
 
 import java.util.List;
 
@@ -42,8 +42,14 @@ public class ToString implements IntrinsicMethod {
             StackValue receiver,
             @NotNull GenerationState state
     ) {
-        receiver.put(AsmTypeConstants.OBJECT_TYPE, v);
+        if (receiver.type.getSort() == Type.OBJECT || receiver.type.getSort() == Type.ARRAY) {
-        v.invokestatic("java/lang/String", "valueOf", "(Ljava/lang/Object;)Ljava/lang/String;");
+            receiver.put(AsmTypeConstants.OBJECT_TYPE, v);
+            v.invokestatic("java/lang/String", "valueOf", "(Ljava/lang/Object;)Ljava/lang/String;");
+        }
+        else {
+            receiver.put(receiver.type, v);
+            v.invokestatic("java/lang/String", "valueOf", "(" + receiver.type.getDescriptor() + ")Ljava/lang/String;");
+        }
         return StackValue.onStack(AsmTypeConstants.JAVA_STRING_TYPE);
     }
 }

compiler/testData/codegen/intrinsics/tostring.kt

@@ -0,0 +1,11 @@
+fun box(): String {
+    if (239.toByte().toString() != (239.toByte() as Byte?).toString()) return "byte failed"
+    if (239.toShort().toString() != (239.toShort() as Short?).toString()) return "short failed"
+    if (239.toInt().toString() != (239.toInt() as Int?).toString()) return "int failed"
+    if (239.toLong().toString() != (239.toLong() as Long?).toString()) return "long failed"
+    if (239.toDouble().toString() != (239.toDouble() as Double?).toString()) return "double failed"
+    if (true.toString() != (true as Boolean?).toString()) return "boolean failed"
+    if ('a'.toChar().toString() != ('a'.toChar() as Char?).toString()) return "char failed"
+    
+    return "OK"
+}

compiler/tests/org/jetbrains/jet/codegen/PrimitiveTypesTest.java

@@ -448,4 +448,8 @@ public class PrimitiveTypesTest extends CodegenTestCase {
     public void testEmptyRanges() throws Exception {
         blackBoxFile("emptyRanges.kt");
     }
+
+    public void testToString() throws Exception {
+        blackBoxFile("intrinsics/tostring.kt");
+    }
 }