JVM_IR don't use Intrinsics.stringPlus for 2-argument concatenation

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

@@ -41561,6 +41561,24 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @Test
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @Test
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @Test
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @Nested

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

@@ -147,13 +147,6 @@ private class JvmStringConcatenationLowering(val context: JvmBackendContext) : F
                 arguments.size == 1 ->
                     lowerInlineClassArgument(arguments[0]) ?: callToString(arguments[0].unwrapImplicitNotNull())
 
-                arguments.size == 2 && arguments[0].type.isStringClassType() ->
-                    irCall(backendContext.ir.symbols.intrinsicStringPlus).apply {
-                        putValueArgument(0, lowerInlineClassArgument(arguments[0]) ?: arguments[0].unwrapImplicitNotNull())
-                        // Unwrapping IMPLICIT_NOTNULL is not strictly necessary on 2nd argument (parameter type is `Any?`)
-                        putValueArgument(1, lowerInlineClassArgument(arguments[1]) ?: arguments[1])
-                    }
-
                 arguments.size < MAX_STRING_CONCAT_DEPTH -> {
                     irCall(toStringFunction).apply {
                         dispatchReceiver = appendWindow(arguments, irCall(constructor))

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmSymbols.kt

@@ -177,9 +177,6 @@ class JvmSymbols(
     override val throwKotlinNothingValueException: IrSimpleFunctionSymbol =
         intrinsicsClass.functions.single { it.owner.name.asString() == "throwKotlinNothingValueException" }
 
-    val intrinsicStringPlus: IrFunctionSymbol =
-        intrinsicsClass.functions.single { it.owner.name.asString() == "stringPlus" }
-
     val intrinsicsKotlinClass: IrClassSymbol =
         (intrinsicsClass.owner.declarations.single { it is IrClass && it.name.asString() == "Kotlin" } as IrClass).symbol
 

compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt

@@ -0,0 +1,17 @@
+fun stringPlus(x: String?, y: Any?) = x + y
+
+fun box(): String {
+    val t1 = stringPlus("a", "b")
+    if (t1 != "ab") return "Failed: t1=$t1"
+
+    val t2 = stringPlus("a", null)
+    if (t2 != "anull") return "Failed: t2=$t2"
+
+    val t3 = stringPlus(null, "b")
+    if (t3 != "nullb") return "Failed: t3=$t3"
+
+    val t4 = stringPlus(null, null)
+    if (t4 != "nullnull") return "Failed: t4=$t4"
+
+    return "OK"
+}

compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt

@@ -0,0 +1,17 @@
+fun stringPlus(x: String?, y: Any?) = x.plus(y)
+
+fun box(): String {
+    val t1 = stringPlus("a", "b")
+    if (t1 != "ab") return "Failed: t1=$t1"
+
+    val t2 = stringPlus("a", null)
+    if (t2 != "anull") return "Failed: t2=$t2"
+
+    val t3 = stringPlus(null, "b")
+    if (t3 != "nullb") return "Failed: t3=$t3"
+
+    val t4 = stringPlus(null, null)
+    if (t4 != "nullnull") return "Failed: t4=$t4"
+
+    return "OK"
+}

compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt

@@ -0,0 +1,17 @@
+fun stringPlus(x: String?, y: Any?) = "$x$y"
+
+fun box(): String {
+    val t1 = stringPlus("a", "b")
+    if (t1 != "ab") return "Failed: t1=$t1"
+
+    val t2 = stringPlus("a", null)
+    if (t2 != "anull") return "Failed: t2=$t2"
+
+    val t3 = stringPlus(null, "b")
+    if (t3 != "nullb") return "Failed: t3=$t3"
+
+    val t4 = stringPlus(null, null)
+    if (t4 != "nullnull") return "Failed: t4=$t4"
+
+    return "OK"
+}

compiler/testData/codegen/bytecodeText/boxingOptimization/maxMinByOrNull.kt

@@ -33,19 +33,8 @@ fun box(): String {
 // 1 IFGE
 // 1 IFLE
 
-// JVM_TEMPLATES
-// -- no boxing but lots of StringBuilder calls
 // 0 valueOf
 // 0 Intrinsics.stringPlus
 // 4 StringBuilder.<init>
 // 8 StringBuilder.append
 // 4 StringBuilder.toString
-
-// JVM_IR_TEMPLATES
-// -- perform boxing and call Intrinsics.stringPlus instead
-// -- of having inlined string builder allocation, appends, and toString
-// 4 valueOf
-// 4 Intrinsics.stringPlus
-// 0 StringBuilder.<init>
-// 0 StringBuilder.append
-// 0 StringBuilder.toString

compiler/testData/codegen/bytecodeText/stringOperations/nullableStringPlus.kt

@@ -1,3 +1,9 @@
 fun foo(x: String?, y: Any?) = x + y
 
+// JVM_TEMPLATES
 // 1 stringPlus
+
+// JVM_IR_TEMPLATES
+// 1 NEW java/lang/StringBuilder
+// 2 INVOKEVIRTUAL java/lang/StringBuilder\.append \(Ljava/lang/Object;\)Ljava/lang/StringBuilder;
+// 1 INVOKEVIRTUAL java/lang/StringBuilder\.toString \(\)Ljava/lang/String;

compiler/testData/codegen/bytecodeText/stringOperations/stringPlus.kt

@@ -1,5 +1,3 @@
-// IGNORE_BACKEND: JVM
-
 fun f(s: String?, t: String): String {
     return s.plus(t)
 }
@@ -12,6 +10,9 @@ fun h(s: String, t: Any?): String {
     return s + t
 }
 
-// 0 valueOf
+// JVM_TEMPLATES
-// 0 NEW java/lang/StringBuilder
+// 1 INVOKESTATIC kotlin/jvm/internal/Intrinsics.stringPlus
-// 3 INVOKESTATIC kotlin/jvm/internal/Intrinsics.stringPlus
+// - used in 's.plus(t)'
+
+// JVM_IR_TEMPLATES
+// 0 INVOKESTATIC kotlin/jvm/internal/Intrinsics.stringPlus

compiler/testData/debug/stepping/smapInlineInIntrinsicArgument.kt

@@ -26,11 +26,13 @@ fun fail() : String {
 // LINENUMBERS
 // test.kt:4 box
 // test.kt:12 box
+// test.kt:4 box
 // test.kt:5 box
 // test.kt:16 fail
 // test.kt:4 box
 // test.kt:7 box
 // test.kt:16 fail
+// test.kt:7 box
 // test.kt:8 box
 // test.kt:12 box
 // test.kt:7 box

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

@@ -41405,6 +41405,24 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @Test
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @Test
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @Test
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @Nested

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

@@ -41561,6 +41561,24 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @Test
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @Test
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @Test
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @Nested

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

@@ -33275,6 +33275,21 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/super")

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

@@ -27800,6 +27800,21 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/super")

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

@@ -27206,6 +27206,21 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/super")

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

@@ -27131,6 +27131,21 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/super")

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

@@ -16415,6 +16415,21 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
         public void testSurrogatePair() throws Exception {
             runTest("compiler/testData/codegen/box/strings/surrogatePair.kt");
         }
+
+        @TestMetadata("twoArgumentNullableStringOperatorPlus.kt")
+        public void testTwoArgumentNullableStringOperatorPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringOperatorPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentNullableStringPlus.kt")
+        public void testTwoArgumentNullableStringPlus() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentNullableStringPlus.kt");
+        }
+
+        @TestMetadata("twoArgumentStringTemplate.kt")
+        public void testTwoArgumentStringTemplate() throws Exception {
+            runTest("compiler/testData/codegen/box/strings/twoArgumentStringTemplate.kt");
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/super")