FIR2IR: simplify operations with getStatementsOrigin

#KT-54989 Fixed

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/ConversionUtils.kt

@@ -725,35 +725,54 @@ fun FirDeclaration?.computeIrOrigin(predefinedOrigin: IrDeclarationOrigin? = nul
 }
 
 fun FirVariableAssignment.getIrAssignmentOrigin(): IrStatementOrigin {
-    val calleeReferenceSymbol = calleeReference?.toResolvedCallableSymbol() ?: return IrStatementOrigin.EQ
+    val callableName = getCallableNameFromIntClassIfAny() ?: return IrStatementOrigin.EQ
+    getIrPrefixPostfixOriginIfAny(callableName)?.let { return it }
+
+    val rValue = rValue as FirFunctionCall
+    val kind = rValue.source?.kind
+    if (kind == KtFakeSourceElementKind.DesugaredIncrementOrDecrement || kind == KtFakeSourceElementKind.DesugaredCompoundAssignment) {
+        if (callableName == OperatorNameConventions.PLUS) {
+            return IrStatementOrigin.PLUSEQ
+        } else if (callableName == OperatorNameConventions.MINUS) {
+            return IrStatementOrigin.MINUSEQ
+        }
+    }
+
+    return IrStatementOrigin.EQ
+}
+
+fun FirVariableAssignment.getIrPrefixPostfixOriginIfAny(): IrStatementOrigin? {
+    val callableName = getCallableNameFromIntClassIfAny() ?: return null
+    return getIrPrefixPostfixOriginIfAny(callableName)
+}
+
+private fun FirVariableAssignment.getIrPrefixPostfixOriginIfAny(
+    callableNameFromIntClass: Name
+): IrStatementOrigin? {
+    if (callableNameFromIntClass == OperatorNameConventions.INC) {
+        return if (source?.elementType == KtNodeTypes.PREFIX_EXPRESSION)
+            IrStatementOrigin.PREFIX_INCR
+        else
+            IrStatementOrigin.POSTFIX_INCR
+    } else if (callableNameFromIntClass == OperatorNameConventions.DEC) {
+        return if (source?.elementType == KtNodeTypes.PREFIX_EXPRESSION)
+            IrStatementOrigin.PREFIX_DECR
+        else
+            IrStatementOrigin.POSTFIX_DECR
+    }
+    return null
+}
+
+private fun FirVariableAssignment.getCallableNameFromIntClassIfAny(): Name? {
+    val calleeReferenceSymbol = calleeReference?.toResolvedCallableSymbol() ?: return null
     val rValue = rValue
     if (rValue is FirFunctionCall && calleeReferenceSymbol.callableId.isLocal) {
         val callableId = rValue.calleeReference.toResolvedCallableSymbol()?.callableId
         if (callableId?.classId == StandardClassIds.Int) {
-            val callableName = callableId.callableName
+            return callableId.callableName
-            if (callableName == OperatorNameConventions.INC) {
-                return if (source?.elementType == KtNodeTypes.PREFIX_EXPRESSION)
-                    IrStatementOrigin.PREFIX_INCR
-                else
-                    IrStatementOrigin.POSTFIX_INCR
-            } else if (callableName == OperatorNameConventions.DEC) {
-                return if (source?.elementType == KtNodeTypes.PREFIX_EXPRESSION)
-                    IrStatementOrigin.PREFIX_DECR
-                else
-                    IrStatementOrigin.POSTFIX_DECR
-            }
-
-            val kind = rValue.source?.kind
-            if (kind == KtFakeSourceElementKind.DesugaredIncrementOrDecrement || kind == KtFakeSourceElementKind.DesugaredCompoundAssignment) {
-                if (callableName == OperatorNameConventions.PLUS) {
-                    return IrStatementOrigin.PLUSEQ
-                } else if (callableName == OperatorNameConventions.MINUS) {
-                    return IrStatementOrigin.MINUSEQ
-                }
-            }
         }
     }
-    return IrStatementOrigin.EQ
+    return null
 }
 
 fun FirCallableDeclaration.contextReceiversForFunctionOrContainingProperty(): List<FirContextReceiver> =
@@ -764,4 +783,4 @@ fun FirCallableDeclaration.contextReceiversForFunctionOrContainingProperty(): Li
 
 fun IrActualizedResult?.extractFirDeclarations(): Set<FirDeclaration>? {
     return this?.actualizedExpectDeclarations?.mapNotNullTo(mutableSetOf()) { ((it as IrMetadataSourceOwner).metadata as FirMetadataSource).fir }
-}
+}

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt

@@ -851,25 +851,10 @@ class Fir2IrVisitor(
     }
 
     private fun List<FirStatement>.getStatementsOrigin(index: Int): IrStatementOrigin? {
-        if (index + 3 > size) return null
+        val incrementStatement = getOrNull(index + 1)
-
-        val statement0 = this[index]
-        if (statement0 !is FirProperty || !statement0.isLocal) return null
-        val unarySymbol = statement0.symbol
-        if (unarySymbol.callableId.callableName != SpecialNames.UNARY) return null
-        val variable = statement0.initializer?.toResolvedCallableSymbol() ?: return null
-
-        val statement2 = this[index + 2]
-        if (statement2 !is FirPropertyAccessExpression) return null
-        if (statement2.calleeReference.toResolvedCallableSymbol() != unarySymbol) return null
-
-        val incrementStatement = this[index + 1]
         if (incrementStatement !is FirVariableAssignment) return null
 
-        if (incrementStatement.calleeReference?.toResolvedCallableSymbol() != variable) return null
+        return incrementStatement.getIrPrefixPostfixOriginIfAny()
-
-        val origin = incrementStatement.getIrAssignmentOrigin()
-        return if (origin == IrStatementOrigin.EQ) null else origin
     }
 
     internal fun convertToIrBlockBody(block: FirBlock): IrBlockBody {