JVM_IR simplify null check on trivially initialized vals only

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -39842,6 +39842,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @Test
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @Test
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {

compiler/ir/backend.jvm/lower/src/org/jetbrains/kotlin/backend/jvm/lower/JvmSafeCallChainFoldingLowering.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.dump
 import org.jetbrains.kotlin.ir.util.hasAnnotation
+import org.jetbrains.kotlin.ir.util.isTrivial
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 import org.jetbrains.kotlin.load.java.JvmAnnotationNames
@@ -83,6 +84,7 @@ class JvmSafeCallChainFoldingLowering(val context: JvmBackendContext) : FileLowe
     //              c
     //      }
     // which can be further simplified depending on the nullability of subexpressions in 'a?.foo() ?: b?.bar()?.qux() ?: c'.
+    // We should perform such simplification carefully, since a value of a non-null type can be uninitialized at runtime.
     // In bytecode this produces a chain of temporary STORE-LOAD and IFNULL checks that can be optimized to a compact sequence
     // of stack operations and IFNULL checks.
 
@@ -119,7 +121,7 @@ class JvmSafeCallChainFoldingLowering(val context: JvmBackendContext) : FileLowe
         IrConstImpl.boolean(startOffset, endOffset, context.irBuiltIns.booleanType, false)
 
     private fun irValNotNull(startOffset: Int, endOffset: Int, irVariable: IrVariable): IrExpression =
-        if (irVariable.type.isJvmNullable())
+        if (irVariable.type.isJvmNullable() || irVariable.initializer?.isTrivial() != true)
             IrGetValueImpl(startOffset, endOffset, irVariable.symbol).irEqEqNull().irNot()
         else
             irTrue(startOffset, endOffset)

compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt

@@ -0,0 +1,18 @@
+abstract class Base() {
+    init {
+        foo()
+    }
+
+    abstract fun foo()
+}
+
+class Derived(val x: String) : Base() {
+    override fun foo() {
+        x?.length
+    }
+}
+
+fun box(): String {
+    Derived("")
+    return "OK"
+}

compiler/testData/codegen/bytecodeText/nullCheckOptimization/safeCallAndElvisChains.kt

@@ -14,5 +14,5 @@ class A(val x: String) {
 
 // JVM_IR_TEMPLATES
 // 4 IFNULL
-// 0 IFNONNULL
+// 2 IFNONNULL
 // 0 ACONST_NULL

compiler/testData/codegen/bytecodeText/temporaryVals/notNullReceiversInChain.kt

@@ -6,8 +6,8 @@ fun test(na: A?) =
     na?.b?.c?.s
 
 // JVM_IR_TEMPLATES
-// 1 DUP
+// 3 DUP
-// 1 IFNULL
+// 3 IFNULL
 // 0 IFNONNULL
 // 1 ACONST_NULL
 

compiler/testData/codegen/bytecodeText/temporaryVals/safeCallChain1.kt

@@ -6,6 +6,6 @@ fun test(an: A?) = an?.b?.c?.s
 
 // JVM_IR_TEMPLATES
 // 0 ASTORE
-// 1 IFNULL
+// 3 IFNULL
 // 0 IFNONNULL
 // 1 ACONST_NULL

compiler/testData/codegen/bytecodeText/temporaryVals/safeCallChainMemberExt1.kt

@@ -13,5 +13,5 @@ object Host {
 // JVM_IR_TEMPLATES
 // 0 ASTORE
 // 1 ACONST_NULL
-// 1 IFNULL
+// 3 IFNULL
 // 0 IFNONNULL

compiler/testData/codegen/bytecodeText/temporaryVals/safeCallChainMemberExt2.kt

@@ -17,5 +17,5 @@ fun test(an: A?) = an?.b?.c?.s
 // JVM_IR_TEMPLATES
 // 0 ASTORE
 // 1 ACONST_NULL
-// 1 IFNULL
+// 3 IFNULL
 // 0 IFNONNULL

compiler/testData/codegen/bytecodeText/temporaryVals/safeCallElvisSafeCallElvisSomething.kt

@@ -3,7 +3,7 @@ fun test(a: Any?, b: Any?, c: String) =
 
 // JVM_IR_TEMPLATES
 // 2 IFNULL
-// 0 IFNONNULL
+// 1 IFNONNULL
 // 0 ACONST_NULL
 
 // JVM_TEMPLATES

compiler/testData/codegen/bytecodeText/temporaryVals/safeCallWithElvis.kt

@@ -9,8 +9,8 @@ fun test(a: Any?) =
 // 0 valueOf
 
 // JVM_IR_TEMPLATES
-// 1 DUP
+// 2 DUP
-// 1 IFNULL
+// 2 IFNULL
 // 0 ACONST_NULL
 // 0 IFNONNULL
 

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -39686,6 +39686,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @Test
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @Test
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -39842,6 +39842,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @Test
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @Test
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {

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

@@ -31768,6 +31768,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {
             runTest("compiler/testData/codegen/box/safeCall/safeCallNotEqPrimitive.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/es6/semantics/IrJsCodegenBoxES6TestGenerated.java

@@ -26918,6 +26918,11 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {
             runTest("compiler/testData/codegen/box/safeCall/safeCallNotEqPrimitive.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -26324,6 +26324,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {
             runTest("compiler/testData/codegen/box/safeCall/safeCallNotEqPrimitive.kt");

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

@@ -26249,6 +26249,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {
             runTest("compiler/testData/codegen/box/safeCall/safeCallNotEqPrimitive.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/wasm/semantics/IrCodegenBoxWasmTestGenerated.java

@@ -15618,6 +15618,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/safeCall/safeCallEqPrimitive.kt");
         }
 
+        @TestMetadata("safeCallIOnUninitializedNonNullValue.kt")
+        public void testSafeCallIOnUninitializedNonNullValue() throws Exception {
+            runTest("compiler/testData/codegen/box/safeCall/safeCallIOnUninitializedNonNullValue.kt");
+        }
+
         @TestMetadata("safeCallNotEqPrimitive.kt")
         public void testSafeCallNotEqPrimitive() throws Exception {
             runTest("compiler/testData/codegen/box/safeCall/safeCallNotEqPrimitive.kt");