Optimize defaults format: avoid reduntant stack normalization operations

compiler/backend/src/org/jetbrains/kotlin/codegen/FunctionCodegen.java

@@ -938,8 +938,6 @@ public class FunctionCodegen {
         InstructionAdapter iv = new InstructionAdapter(mv);
         genDefaultSuperCallCheckIfNeeded(iv, functionDescriptor, defaultMethod);
 
-        loadExplicitArgumentsOnStack(OBJECT_TYPE, isStatic, signature, generator);
-
         List<JvmMethodParameterSignature> mappedParameters = signature.getValueParameters();
         int capturedArgumentsCount = 0;
         while (capturedArgumentsCount < mappedParameters.size() &&
@@ -968,7 +966,15 @@ public class FunctionCodegen {
 
                 iv.mark(loadArg);
             }
+        }
 
+        // load arguments after defaults generation to avoid redundant stack normalization operations
+        loadExplicitArgumentsOnStack(OBJECT_TYPE, isStatic, signature, generator);
+
+        for (int index = 0; index < valueParameters.size(); index++) {
+            ValueParameterDescriptor parameterDescriptor = valueParameters.get(index);
+            Type type = mappedParameters.get(capturedArgumentsCount + index).getAsmType();
+            int parameterIndex = frameMap.getIndex(parameterDescriptor);
             generator.putValueIfNeeded(type, StackValue.local(parameterIndex, type));
         }
 

compiler/testData/codegen/bytecodeText/defaultMethodBody.kt

@@ -0,0 +1,5 @@
+fun test(a: Int, z: String = try{"1"} catch (e: Exception) {"2"}) {
+    "Default body"
+}
+
+//1 ILOAD 0\s*ALOAD 1\s*INVOKESTATIC DefaultMethodBodyKt\.test \(ILjava/lang/String;\)V

compiler/tests/org/jetbrains/kotlin/codegen/BytecodeTextTestGenerated.java

@@ -120,6 +120,12 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
         doTest(fileName);
     }
 
+    @TestMetadata("defaultMethodBody.kt")
+    public void testDefaultMethodBody() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/defaultMethodBody.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("falseSmartCast.kt")
     public void testFalseSmartCast() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/falseSmartCast.kt");