Skip call to the underlying value of inline class

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

@@ -1672,14 +1672,13 @@ public class ExpressionCodegen extends KtVisitor<StackValue, StackValue> impleme
         if (descriptor instanceof PropertyDescriptor) {
             PropertyDescriptor propertyDescriptor = (PropertyDescriptor) descriptor;
 
-            // `this` is represented as first parameter of function in erased inline class
-            boolean isThisOfErasedInlineClass =
-                    contextKind() == OwnerKind.ERASED_INLINE_CLASS &&
+            boolean isUnderlyingPropertyOfInlineClass =
                     InlineClassesUtilsKt.isInlineClass(propertyDescriptor.getContainingDeclaration()) &&
                     JvmCodegenUtil.hasBackingField(propertyDescriptor, contextKind(), bindingContext);
-            if (isThisOfErasedInlineClass) {
-                Type underlyingRepresentationType = typeMapper.mapType(propertyDescriptor.getType());
-                return StackValue.local(0, underlyingRepresentationType);
+
+            if (isUnderlyingPropertyOfInlineClass) {
+                KotlinType propertyType = propertyDescriptor.getType();
+                return StackValue.underlyingValueOfInlineClass(typeMapper.mapType(propertyType), propertyType, receiver);
             }
 
             Collection<ExpressionCodegenExtension> codegenExtensions = ExpressionCodegenExtension.Companion.getInstances(state.getProject());

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

@@ -291,6 +291,14 @@ public abstract class StackValue {
         return new CollectionElement(collectionElementReceiver, type, kotlinType, getter, setter, codegen);
     }
 
+    public static UnderlyingValueOfInlineClass underlyingValueOfInlineClass(
+            @NotNull Type type,
+            @Nullable KotlinType kotlinType,
+            @NotNull StackValue receiver
+    ) {
+        return new UnderlyingValueOfInlineClass(type, kotlinType, receiver);
+    }
+
     @NotNull
     public static Field field(@NotNull Type type, @NotNull Type owner, @NotNull String name, boolean isStatic, @NotNull StackValue receiver) {
         return field(type, null, owner, name, isStatic, receiver, null);
@@ -1004,6 +1012,24 @@ public abstract class StackValue {
         }
     }
 
+    public static class UnderlyingValueOfInlineClass extends StackValueWithSimpleReceiver {
+
+        public UnderlyingValueOfInlineClass(
+                @NotNull Type type,
+                @Nullable KotlinType kotlinType,
+                @NotNull StackValue receiver
+        ) {
+            super(type, kotlinType, false, false, receiver, true);
+        }
+
+        @Override
+        public void putSelector(
+                @NotNull Type type, @Nullable KotlinType kotlinType, @NotNull InstructionAdapter v
+        ) {
+            coerceTo(type, kotlinType, v);
+        }
+    }
+
     public static class CollectionElementReceiver extends StackValue {
         private final Callable callable;
         private final boolean isGetter;

compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyInsideInlineClass.kt

@@ -0,0 +1,16 @@
+// !LANGUAGE: +InlineClasses
+
+inline class UInt(val value: Int) {
+    operator fun plus(other: UInt) = UInt(value + other.value)
+    fun otherValue(other: UInt) = other.value
+}
+
+fun box(): String {
+    val a = UInt(10)
+    val b = UInt(20)
+    if (a.otherValue(b) != 20) return "fail 1"
+
+    if ((a + b).value != 30) return "fail 2"
+
+    return "OK"
+}

compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyOfInlineClass.kt

@@ -0,0 +1,16 @@
+// !LANGUAGE: +InlineClasses
+
+inline class UInt(val value: Int)
+
+fun box(): String {
+    val a = UInt(123)
+    if(a.value != 123) return "fail"
+
+    val c = a.value.hashCode()
+    if (c.hashCode() != 123.hashCode()) return "fail"
+
+    val b = UInt(100).value + a.value
+    if (b != 223) return "faile"
+
+    return "OK"
+}

compiler/testData/codegen/bytecodeText/inlineClasses/skipCallToUnderlyingValueOfInlineClass.kt

@@ -0,0 +1,17 @@
+// !LANGUAGE: +InlineClasses
+
+inline class UInt(val value: Int)
+
+fun test(u1: UInt, u2: UInt) {
+    val a = u1.value
+
+    val b = u1.value.hashCode() // box int to call hashCode
+    val c = u1.value + u2.value
+}
+
+// 0 INVOKESTATIC UInt\$Erased.getValue
+// 0 INVOKESTATIC UInt\$Erased.box
+// 0 INVOKEVIRTUAL UInt.unbox
+
+// 1 valueOf
+// 0 intValue

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -10467,6 +10467,18 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             doTest(fileName);
         }
 
+        @TestMetadata("referToUnderlyingPropertyInsideInlineClass.kt")
+        public void testReferToUnderlyingPropertyInsideInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyInsideInlineClass.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("referToUnderlyingPropertyOfInlineClass.kt")
+        public void testReferToUnderlyingPropertyOfInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyOfInlineClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("UIntArraySortExample.kt")
         public void testUIntArraySortExample() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/UIntArraySortExample.kt");

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

@@ -10467,6 +10467,18 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("referToUnderlyingPropertyInsideInlineClass.kt")
+        public void testReferToUnderlyingPropertyInsideInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyInsideInlineClass.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("referToUnderlyingPropertyOfInlineClass.kt")
+        public void testReferToUnderlyingPropertyOfInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyOfInlineClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("UIntArraySortExample.kt")
         public void testUIntArraySortExample() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/UIntArraySortExample.kt");

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

@@ -1974,6 +1974,12 @@ public class BytecodeTextTestGenerated extends AbstractBytecodeTextTest {
             doTest(fileName);
         }
 
+        @TestMetadata("skipCallToUnderlyingValueOfInlineClass.kt")
+        public void testSkipCallToUnderlyingValueOfInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/inlineClasses/skipCallToUnderlyingValueOfInlineClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("uIntArrayIteratorWithoutBoxing.kt")
         public void testUIntArrayIteratorWithoutBoxing() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeText/inlineClasses/uIntArrayIteratorWithoutBoxing.kt");

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

@@ -10467,6 +10467,18 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             doTest(fileName);
         }
 
+        @TestMetadata("referToUnderlyingPropertyInsideInlineClass.kt")
+        public void testReferToUnderlyingPropertyInsideInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyInsideInlineClass.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("referToUnderlyingPropertyOfInlineClass.kt")
+        public void testReferToUnderlyingPropertyOfInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyOfInlineClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("UIntArraySortExample.kt")
         public void testUIntArraySortExample() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/UIntArraySortExample.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -11451,6 +11451,18 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             doTest(fileName);
         }
 
+        @TestMetadata("referToUnderlyingPropertyInsideInlineClass.kt")
+        public void testReferToUnderlyingPropertyInsideInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyInsideInlineClass.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("referToUnderlyingPropertyOfInlineClass.kt")
+        public void testReferToUnderlyingPropertyOfInlineClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/referToUnderlyingPropertyOfInlineClass.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("UIntArraySortExample.kt")
         public void testUIntArraySortExample() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/inlineClasses/UIntArraySortExample.kt");