From 2680111125a4cce28e530f401760b778ea62a786 Mon Sep 17 00:00:00 2001
From: Pavel Kunyavskiy <pavel.kunyavskiy@jetbrains.com>
Date: Tue, 18 May 2021 14:22:16 +0300
Subject: [PATCH] [K/N] Fix order of lowerings to enable when on enum
 optimisation

EnumWhenLowering searches for pattern, which is destroyed by
BuiltinOperatorLowering, so first one should happen before second.
---
 .../backend/konan/KonanLoweringPhases.kt      | 23 +++++++++++++++----
 .../kotlin/backend/konan/ToplevelPhases.kt    |  2 ++
 .../backend/konan/lower/EnumClassLowering.kt  |  8 -------
 3 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanLoweringPhases.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanLoweringPhases.kt
index 8c4587e6225..ef7e0c00c6b 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanLoweringPhases.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanLoweringPhases.kt
@@ -288,13 +288,28 @@ internal val functionReferencePhase = makeKonanFileLoweringPhase(
         prerequisite = setOf(delegationPhase, localFunctionsPhase) // TODO: make weak dependency on `testProcessorPhase`
 )
 
-internal val enumClassPhase = makeKonanFileOpPhase(
-        { context, irFile -> EnumClassLowering(context).run(irFile) },
+internal val enumWhenPhase = makeKonanFileLoweringPhase(
+        ::NativeEnumWhenLowering,
+        name = "EnumWhen",
+        description = "Enum when lowering",
+        prerequisite = setOf(enumConstructorsPhase, functionReferencePhase)
+)
+
+internal val enumClassPhase = makeKonanFileLoweringPhase(
+        ::EnumClassLowering,
         name = "Enums",
         description = "Enum classes lowering",
-        prerequisite = setOf(enumConstructorsPhase, functionReferencePhase) // TODO: make weak dependency on `testProcessorPhase`
+        prerequisite = setOf(enumConstructorsPhase, functionReferencePhase, enumWhenPhase) // TODO: make weak dependency on `testProcessorPhase`
 )
 
+internal val enumUsagePhase = makeKonanFileLoweringPhase(
+        ::EnumUsageLowering,
+        name = "EnumUsage",
+        description = "Enum usage lowering",
+        prerequisite = setOf(enumConstructorsPhase, functionReferencePhase, enumClassPhase)
+)
+
+
 internal val singleAbstractMethodPhase = makeKonanFileLoweringPhase(
         ::NativeSingleAbstractMethodLowering,
         name = "SingleAbstractMethod",
@@ -306,7 +321,7 @@ internal val builtinOperatorPhase = makeKonanFileLoweringPhase(
         ::BuiltinOperatorLowering,
         name = "BuiltinOperators",
         description = "BuiltIn operators lowering",
-        prerequisite = setOf(defaultParameterExtentPhase, singleAbstractMethodPhase)
+        prerequisite = setOf(defaultParameterExtentPhase, singleAbstractMethodPhase, enumWhenPhase)
 )
 
 internal val interopPhase = makeKonanFileLoweringPhase(
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt
index 9f00fba0f2a..b6ca06e7320 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ToplevelPhases.kt
@@ -217,9 +217,11 @@ internal val allLoweringsPhase = NamedCompilerPhase(
                             delegationPhase,
                             functionReferencePhase,
                             singleAbstractMethodPhase,
+                            enumWhenPhase,
                             builtinOperatorPhase,
                             finallyBlocksPhase,
                             enumClassPhase,
+                            enumUsagePhase,
                             interopPhase,
                             varargPhase,
                             compileTimeEvaluatePhase,
diff --git a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/EnumClassLowering.kt b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/EnumClassLowering.kt
index 78c0623c439..4843cb4d0b9 100644
--- a/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/EnumClassLowering.kt
+++ b/kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/lower/EnumClassLowering.kt
@@ -120,14 +120,6 @@ internal class EnumUsageLowering(val context: Context)
 
 internal class EnumClassLowering(val context: Context) : FileLoweringPass {
 
-    fun run(irFile: IrFile) {
-        // EnumWhenLowering should be performed before EnumUsageLowering because
-        // the latter performs lowering of IrGetEnumValue
-        NativeEnumWhenLowering(context).lower(irFile)
-        lower(irFile)
-        EnumUsageLowering(context).lower(irFile)
-    }
-
     override fun lower(irFile: IrFile) {
         irFile.transformChildrenVoid(object : IrElementTransformerVoid() {
             override fun visitClass(declaration: IrClass): IrStatement {