psi2ir: don't generate temporaries in dynamic array augmented assignment

In constructs such as 'd[i] += x', where both indexed get and indexed
set are dynamic calls, it's safe to generate augmented assignment body
directly, without temporary variables for array ('d') and index ('i').
Note that corresponding IntermediateValue's are OnceExpressionValue's,
which would throw an exception if this assumption is violated.

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/intermediate/ArrayAccessAssignmentReceiver.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.psi.KtExpression
 import org.jetbrains.kotlin.psi2ir.generators.CallGenerator
 import org.jetbrains.kotlin.psi2ir.generators.pregenerateValueArgumentsUsing
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
+import org.jetbrains.kotlin.resolve.calls.tasks.isDynamic
 import org.jetbrains.kotlin.types.KotlinType
 
 class ArrayAccessAssignmentReceiver(
@@ -42,32 +43,59 @@ class ArrayAccessAssignmentReceiver(
     private val origin: IrStatementOrigin
 ) : AssignmentReceiver {
 
+    private val indexedGetDescriptor = indexedGetResolvedCall?.resultingDescriptor
+    private val indexedSetDescriptor = indexedSetResolvedCall?.resultingDescriptor
+
     private val descriptor =
-        indexedGetResolvedCall?.resultingDescriptor
+        indexedGetDescriptor
-            ?: indexedSetResolvedCall?.resultingDescriptor
+            ?: indexedSetDescriptor
             ?: throw AssertionError("Array access should have either indexed-get call or indexed-set call")
 
     override fun assign(withLValue: (LValue) -> IrExpression): IrExpression {
         val kotlinType: KotlinType =
-            indexedGetResolvedCall?.run { resultingDescriptor.returnType!! }
+            indexedGetDescriptor?.returnType
-                ?: indexedSetResolvedCall?.run { resultingDescriptor.valueParameters.last().type }
+                ?: indexedSetDescriptor?.run { valueParameters.last().type }
                 ?: throw AssertionError("Array access should have either indexed-get call or indexed-set call")
 
         val hasResult = origin.isAssignmentOperatorWithResult()
         val resultType = if (hasResult) kotlinType else callGenerator.context.builtIns.unitType
         val irResultType = callGenerator.translateType(resultType)
+
+        if (indexedGetDescriptor?.isDynamic() != false && indexedSetDescriptor?.isDynamic() != false) {
+            return withLValue(
+                createLValue(kotlinType, OnceExpressionValue(irArray)) { _, irIndex ->
+                    OnceExpressionValue(irIndex)
+                }
+            )
+        }
+
         val irBlock = IrBlockImpl(startOffset, endOffset, irResultType, origin)
 
         val irArrayValue = callGenerator.scope.createTemporaryVariableInBlock(callGenerator.context, irArray, irBlock, "array")
 
-        val ktExpressionToIrIndexValue = HashMap<KtExpression, IntermediateValue>()
+        irBlock.inlineStatement(
+            withLValue(
+                createLValue(kotlinType, irArrayValue) { i, irIndex ->
+                    callGenerator.scope.createTemporaryVariableInBlock(callGenerator.context, irIndex, irBlock, "index$i")
+                }
+            )
+        )
 
+        return irBlock
+    }
+
+    private fun createLValue(
+        kotlinType: KotlinType,
+        irArrayValue: IntermediateValue,
+        createIndexValue: (Int, IrExpression) -> IntermediateValue
+    ): LValueWithGetterAndSetterCalls {
+        val ktExpressionToIrIndexValue = HashMap<KtExpression, IntermediateValue>()
         for ((i, irIndex) in irIndexExpressions.withIndex()) {
             ktExpressionToIrIndexValue[ktIndexExpressions[i]] =
-                    callGenerator.scope.createTemporaryVariableInBlock(callGenerator.context, irIndex, irBlock, "index$i")
+                createIndexValue(i, irIndex)
         }
 
-        val irLValue = LValueWithGetterAndSetterCalls(
+        return LValueWithGetterAndSetterCalls(
             callGenerator,
             descriptor,
             { indexedGetCall()?.fillArrayAndIndexArguments(irArrayValue, indexedGetResolvedCall!!, ktExpressionToIrIndexValue) },
@@ -75,9 +103,6 @@ class ArrayAccessAssignmentReceiver(
             callGenerator.translateType(kotlinType),
             startOffset, endOffset, origin
         )
-        irBlock.inlineStatement(withLValue(irLValue))
-
-        return irBlock
     }
 
     override fun assign(value: IrExpression): IrExpression {

compiler/testData/ir/irJsText/dynamic/dynamicArrayAugmentedAssignment.txt

@@ -2,53 +2,28 @@ FILE fqName:<root> fileName:/dynamicArrayAugmentedAssignment.kt
   FUN name:testArrayAugmentedAssignment visibility:public modality:FINAL <> (d:dynamic) returnType:kotlin.Unit flags:
     VALUE_PARAMETER name:d index:0 type:dynamic flags:
     BLOCK_BODY
-      BLOCK type=kotlin.Unit origin=PLUSEQ
+      DYN_OP operator=PLUSEQ type=kotlin.Unit
-        VAR IR_TEMPORARY_VARIABLE name:tmp0_array type:dynamic flags:val
+        receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-          GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
+          receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-        VAR IR_TEMPORARY_VARIABLE name:tmp1_index0 type:kotlin.String flags:val
+          0: CONST String type=kotlin.String value="KEY"
-          CONST String type=kotlin.String value="KEY"
+        0: CONST String type=kotlin.String value="+="
-        DYN_OP operator=PLUSEQ type=kotlin.Unit
+      DYN_OP operator=MINUSEQ type=kotlin.Unit
-          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
+        receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            receiver: GET_VAR 'tmp0_array: dynamic' type=dynamic origin=null
+          receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-            0: GET_VAR 'tmp1_index0: String' type=kotlin.String origin=null
+          0: CONST String type=kotlin.String value="KEY"
-          0: CONST String type=kotlin.String value="+="
+        0: CONST String type=kotlin.String value="-="
-      BLOCK type=kotlin.Unit origin=MINUSEQ
+      DYN_OP operator=MULEQ type=kotlin.Unit
-        VAR IR_TEMPORARY_VARIABLE name:tmp2_array type:dynamic flags:val
+        receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-          GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
+          receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-        VAR IR_TEMPORARY_VARIABLE name:tmp3_index0 type:kotlin.String flags:val
+          0: CONST String type=kotlin.String value="KEY"
-          CONST String type=kotlin.String value="KEY"
+        0: CONST String type=kotlin.String value="*="
-        DYN_OP operator=MINUSEQ type=kotlin.Unit
+      DYN_OP operator=DIVEQ type=kotlin.Unit
-          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
+        receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            receiver: GET_VAR 'tmp2_array: dynamic' type=dynamic origin=null
+          receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-            0: GET_VAR 'tmp3_index0: String' type=kotlin.String origin=null
+          0: CONST String type=kotlin.String value="KEY"
-          0: CONST String type=kotlin.String value="-="
+        0: CONST String type=kotlin.String value="/="
-      BLOCK type=kotlin.Unit origin=MULTEQ
+      DYN_OP operator=MODEQ type=kotlin.Unit
-        VAR IR_TEMPORARY_VARIABLE name:tmp4_array type:dynamic flags:val
+        receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-          GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
+          receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-        VAR IR_TEMPORARY_VARIABLE name:tmp5_index0 type:kotlin.String flags:val
+          0: CONST String type=kotlin.String value="KEY"
-          CONST String type=kotlin.String value="KEY"
+        0: CONST String type=kotlin.String value="%="
-        DYN_OP operator=MULEQ type=kotlin.Unit
-          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            receiver: GET_VAR 'tmp4_array: dynamic' type=dynamic origin=null
-            0: GET_VAR 'tmp5_index0: String' type=kotlin.String origin=null
-          0: CONST String type=kotlin.String value="*="
-      BLOCK type=kotlin.Unit origin=DIVEQ
-        VAR IR_TEMPORARY_VARIABLE name:tmp6_array type:dynamic flags:val
-          GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-        VAR IR_TEMPORARY_VARIABLE name:tmp7_index0 type:kotlin.String flags:val
-          CONST String type=kotlin.String value="KEY"
-        DYN_OP operator=DIVEQ type=kotlin.Unit
-          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            receiver: GET_VAR 'tmp6_array: dynamic' type=dynamic origin=null
-            0: GET_VAR 'tmp7_index0: String' type=kotlin.String origin=null
-          0: CONST String type=kotlin.String value="/="
-      BLOCK type=kotlin.Unit origin=PERCEQ
-        VAR IR_TEMPORARY_VARIABLE name:tmp8_array type:dynamic flags:val
-          GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-        VAR IR_TEMPORARY_VARIABLE name:tmp9_index0 type:kotlin.String flags:val
-          CONST String type=kotlin.String value="KEY"
-        DYN_OP operator=MODEQ type=kotlin.Unit
-          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            receiver: GET_VAR 'tmp8_array: dynamic' type=dynamic origin=null
-            0: GET_VAR 'tmp9_index0: String' type=kotlin.String origin=null
-          0: CONST String type=kotlin.String value="%="

compiler/testData/ir/irJsText/dynamic/dynamicArrayIncrementDecrement.txt

@@ -3,42 +3,22 @@ FILE fqName:<root> fileName:/dynamicArrayIncrementDecrement.kt
     VALUE_PARAMETER name:d index:0 type:dynamic flags:
     BLOCK_BODY
       VAR name:t1 type:dynamic flags:val
-        BLOCK type=dynamic origin=PREFIX_INCR
+        DYN_OP operator=PREFIX_INCREMENT type=dynamic
-          VAR IR_TEMPORARY_VARIABLE name:tmp0_array type:dynamic flags:val
+          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
+            receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-          VAR IR_TEMPORARY_VARIABLE name:tmp1_index0 type:kotlin.String flags:val
+            0: CONST String type=kotlin.String value="prefixIncr"
-            CONST String type=kotlin.String value="prefixIncr"
-          DYN_OP operator=PREFIX_INCREMENT type=dynamic
-            receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-              receiver: GET_VAR 'tmp0_array: dynamic' type=dynamic origin=null
-              0: GET_VAR 'tmp1_index0: String' type=kotlin.String origin=null
       VAR name:t2 type:dynamic flags:val
-        BLOCK type=dynamic origin=PREFIX_DECR
+        DYN_OP operator=PREFIX_DECREMENT type=dynamic
-          VAR IR_TEMPORARY_VARIABLE name:tmp2_array type:dynamic flags:val
+          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
+            receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-          VAR IR_TEMPORARY_VARIABLE name:tmp3_index0 type:kotlin.String flags:val
+            0: CONST String type=kotlin.String value="prefixDecr"
-            CONST String type=kotlin.String value="prefixDecr"
-          DYN_OP operator=PREFIX_DECREMENT type=dynamic
-            receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-              receiver: GET_VAR 'tmp2_array: dynamic' type=dynamic origin=null
-              0: GET_VAR 'tmp3_index0: String' type=kotlin.String origin=null
       VAR name:t3 type:dynamic flags:val
-        BLOCK type=dynamic origin=POSTFIX_INCR
+        DYN_OP operator=POSTFIX_INCREMENT type=dynamic
-          VAR IR_TEMPORARY_VARIABLE name:tmp4_array type:dynamic flags:val
+          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
+            receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-          VAR IR_TEMPORARY_VARIABLE name:tmp5_index0 type:kotlin.String flags:val
+            0: CONST String type=kotlin.String value="postfixIncr"
-            CONST String type=kotlin.String value="postfixIncr"
-          DYN_OP operator=POSTFIX_INCREMENT type=dynamic
-            receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-              receiver: GET_VAR 'tmp4_array: dynamic' type=dynamic origin=null
-              0: GET_VAR 'tmp5_index0: String' type=kotlin.String origin=null
       VAR name:t4 type:dynamic flags:val
-        BLOCK type=dynamic origin=POSTFIX_DECR
+        DYN_OP operator=POSTFIX_DECREMENT type=dynamic
-          VAR IR_TEMPORARY_VARIABLE name:tmp6_array type:dynamic flags:val
+          receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-            GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
+            receiver: GET_VAR 'value-parameter d: dynamic' type=dynamic origin=null
-          VAR IR_TEMPORARY_VARIABLE name:tmp7_index0 type:kotlin.String flags:val
+            0: CONST String type=kotlin.String value="postfixDecr"
-            CONST String type=kotlin.String value="postfixDecr"
-          DYN_OP operator=POSTFIX_DECREMENT type=dynamic
-            receiver: DYN_OP operator=ARRAY_ACCESS type=dynamic
-              receiver: GET_VAR 'tmp6_array: dynamic' type=dynamic origin=null
-              0: GET_VAR 'tmp7_index0: String' type=kotlin.String origin=null