Revert "JVM IR: Implement CHECK_NOT_NULL as a lowering"

This reverts commit dcd72b06d8.

Using a temporary variable has an effect on casts and GC.

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

@@ -326,7 +326,6 @@ private val jvmFilePhases = listOf(
     polymorphicSignaturePhase,
     varargPhase,
     arrayConstructorPhase,
-    checkNotNullPhase,
 
     lateinitNullableFieldsPhase,
     lateinitDeclarationLoweringPhase,

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/intrinsics/IrCheckNotNull.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.backend.jvm.intrinsics
+
+import org.jetbrains.kotlin.backend.jvm.codegen.*
+import org.jetbrains.kotlin.codegen.AsmUtil
+import org.jetbrains.kotlin.codegen.intrinsics.IntrinsicMethods
+import org.jetbrains.kotlin.ir.expressions.IrFunctionAccessExpression
+import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.org.objectweb.asm.Label
+import org.jetbrains.org.objectweb.asm.Type
+
+private fun ExpressionCodegen.checkTopValueForNull() {
+    mv.dup()
+    if (state.unifiedNullChecks) {
+        mv.invokestatic(IntrinsicMethods.INTRINSICS_CLASS_NAME, "checkNotNull", "(Ljava/lang/Object;)V", false)
+    } else {
+        val ifNonNullLabel = Label()
+        mv.ifnonnull(ifNonNullLabel)
+        mv.invokestatic(IntrinsicMethods.INTRINSICS_CLASS_NAME, "throwNpe", "()V", false)
+        mv.mark(ifNonNullLabel)
+    }
+}
+
+object IrCheckNotNull : IntrinsicMethod() {
+    override fun invoke(expression: IrFunctionAccessExpression, codegen: ExpressionCodegen, data: BlockInfo): PromisedValue? {
+        val arg0 = expression.getValueArgument(0)!!.accept(codegen, data)
+        if (AsmUtil.isPrimitive(arg0.type)) return arg0
+        return object : PromisedValue(codegen, arg0.type, expression.type) {
+            override fun materializeAt(target: Type, irTarget: IrType, castForReified: Boolean) =
+                arg0.materialized().also { codegen.checkTopValueForNull() }.materializeAt(target, irTarget, castForReified)
+
+            override fun discard() =
+                arg0.materialized().also { codegen.checkTopValueForNull() }.discard()
+        }
+    }
+}

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/intrinsics/IrIntrinsicMethods.kt

@@ -110,6 +110,7 @@ class IrIntrinsicMethods(val irBuiltIns: IrBuiltIns, val symbols: JvmSymbols) {
                 irBuiltIns.booleanNotSymbol.toKey()!! to Not,
                 irBuiltIns.noWhenBranchMatchedExceptionSymbol.toKey()!! to IrNoWhenBranchMatchedException,
                 irBuiltIns.illegalArgumentExceptionSymbol.toKey()!! to IrIllegalArgumentException,
+                irBuiltIns.checkNotNullSymbol.toKey()!! to IrCheckNotNull,
                 irBuiltIns.andandSymbol.toKey()!! to AndAnd,
                 irBuiltIns.ororSymbol.toKey()!! to OrOr,
                 irBuiltIns.dataClassArrayMemberHashCodeSymbol.toKey()!! to IrDataClassArrayMemberHashCode,

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

@@ -1,56 +0,0 @@
-/*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
- * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
- */
-
-package org.jetbrains.kotlin.backend.jvm.lower
-
-import org.jetbrains.kotlin.backend.common.FileLoweringPass
-import org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext
-import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
-import org.jetbrains.kotlin.backend.common.lower.irIfThen
-import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
-import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
-import org.jetbrains.kotlin.ir.builders.*
-import org.jetbrains.kotlin.ir.declarations.IrFile
-import org.jetbrains.kotlin.ir.expressions.IrCall
-import org.jetbrains.kotlin.ir.expressions.IrExpression
-import org.jetbrains.kotlin.ir.expressions.IrGetValue
-
-internal val checkNotNullPhase = makeIrFilePhase(
-    ::CheckNotNullLowering,
-    name = "CheckNotNullLowering",
-    description = "Lower calls to the CHECK_NOT_NULL intrinsic, which are generated by psi2ir for \"!!\" expressions."
-)
-
-private class CheckNotNullLowering(private val backendContext: JvmBackendContext) : FileLoweringPass, IrElementTransformerVoidWithContext() {
-    override fun lower(irFile: IrFile) = irFile.transformChildrenVoid()
-
-    override fun visitCall(expression: IrCall): IrExpression {
-        if (expression.symbol != backendContext.irBuiltIns.checkNotNullSymbol)
-            return super.visitCall(expression)
-
-        expression.transformChildrenVoid()
-        return backendContext.createIrBuilder(currentScope!!.scope.scopeOwnerSymbol, expression.startOffset, expression.endOffset).irBlock {
-            val valueArgument = expression.getValueArgument(0)!!
-
-            // For a null-check on a variable we should not introduce a temporary, since null checks are
-            // optimized by RedundantNullCheckMethodTransformer, which remembers that the argument variable
-            // is non-nullable if this call succeeds.
-            val argument = if (valueArgument is IrGetValue) valueArgument.symbol.owner else irTemporary(valueArgument)
-
-            // Starting with Kotlin 1.4 null-checks are lowered to calls to the "checkNotNull" intrinsic, which
-            // throws a NullPointerException on failure. Prior to Kotlin 1.4 we instead inline the null-check and
-            // call the "throwNpe" intrinsic on failure which throws a KotlinNullPointerException.
-            if (backendContext.state.unifiedNullChecks) {
-                +irCall(backendContext.ir.symbols.checkNotNull).apply {
-                    putValueArgument(0, irGet(argument))
-                }
-            } else {
-                +irIfThen(irEqualsNull(irGet(argument)), irCall(backendContext.ir.symbols.throwNpe))
-            }
-
-            +irImplicitCast(irGet(argument), expression.type)
-        }
-    }
-}