Support const-bounded for loop generation for reversed 'until'

compiler/backend/src/org/jetbrains/kotlin/codegen/range/PrimitiveNumberRangeIntrinsicRangeValue.kt

@@ -76,7 +76,8 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
             forExpression: KtForExpression,
             startValue: StackValue,
             endExpression: KtExpression,
-            step: Int
+            step: Int,
+            isStartInclusive: Boolean = true
     ): ForLoopGenerator? {
         val endConstValue = codegen.getCompileTimeConstant(endExpression).safeAs<IntegerValueConstant<*>>() ?: return null
 
@@ -86,7 +87,7 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
                 if (isProhibitedIntConstEndValue(step, endIntValue))
                     null
                 else
-                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endIntValue, step)
+                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endIntValue, step, isStartInclusive)
             }
 
             is ShortValue -> {
@@ -94,7 +95,7 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
                 if (isProhibitedIntConstEndValue(step, endIntValue))
                     null
                 else
-                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endIntValue, step)
+                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endIntValue, step, isStartInclusive)
             }
 
             is IntValue -> {
@@ -102,7 +103,7 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
                 if (isProhibitedIntConstEndValue(step, endIntValue))
                     null
                 else
-                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endIntValue, step)
+                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endIntValue, step, isStartInclusive)
             }
 
             is CharValue -> {
@@ -110,7 +111,7 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
                 if (isProhibitedCharConstEndValue(step, endCharValue))
                     null
                 else
-                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endCharValue.toInt(), step)
+                    createConstBoundedIntForLoopGenerator(codegen, forExpression, startValue, endCharValue.toInt(), step, isStartInclusive)
             }
 
             is LongValue -> {
@@ -118,7 +119,7 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
                 if (isProhibitedLongConstEndValue(step, endLongValue))
                     null
                 else
-                    createConstBoundedLongForLoopGenerator(codegen, forExpression, startValue, endLongValue, step)
+                    createConstBoundedLongForLoopGenerator(codegen, forExpression, startValue, endLongValue, step, isStartInclusive)
             }
 
             else -> null
@@ -130,12 +131,13 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
             forExpression: KtForExpression,
             startValue: StackValue,
             endIntValue: Int,
-            step: Int
+            step: Int,
+            isStartInclusive: Boolean
     ): ForLoopGenerator? =
             ForInDefinitelySafeSimpleProgressionLoopGenerator(
                     codegen, forExpression,
                     startValue = startValue,
-                    isStartInclusive = true,
+                    isStartInclusive = isStartInclusive,
                     endValue = StackValue.integerConstant(endIntValue, asmElementType),
                     isEndInclusive = true,
                     step = step
@@ -146,12 +148,13 @@ abstract class PrimitiveNumberRangeIntrinsicRangeValue(
             forExpression: KtForExpression,
             startValue: StackValue,
             endLongValue: Long,
-            step: Int
+            step: Int,
+            isStartInclusive: Boolean
     ): ForLoopGenerator? =
             ForInDefinitelySafeSimpleProgressionLoopGenerator(
                     codegen, forExpression,
                     startValue = startValue,
-                    isStartInclusive = true,
+                    isStartInclusive = isStartInclusive,
                     endValue = StackValue.constant(endLongValue, asmElementType),
                     isEndInclusive = true,
                     step = step

compiler/backend/src/org/jetbrains/kotlin/codegen/range/PrimitiveNumberUntilRangeValue.kt

@@ -17,9 +17,12 @@
 package org.jetbrains.kotlin.codegen.range
 
 import org.jetbrains.kotlin.codegen.ExpressionCodegen
+import org.jetbrains.kotlin.codegen.generateCallSingleArgument
 import org.jetbrains.kotlin.codegen.range.forLoop.ForInSimpleProgressionLoopGenerator
+import org.jetbrains.kotlin.codegen.range.forLoop.ForLoopGenerator
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.psi.KtForExpression
+import org.jetbrains.kotlin.resolve.calls.callUtil.getReceiverExpression
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
 
 class PrimitiveNumberUntilRangeValue(rangeCall: ResolvedCall<out CallableDescriptor>) :
@@ -32,5 +35,20 @@ class PrimitiveNumberUntilRangeValue(rangeCall: ResolvedCall<out CallableDescrip
             ForInSimpleProgressionLoopGenerator.fromBoundedValueWithStep1(codegen, forExpression, getBoundedValue(codegen))
 
     override fun createForInReversedLoopGenerator(codegen: ExpressionCodegen, forExpression: KtForExpression) =
+            createConstBoundedForInReversedUntilGenerator(codegen, forExpression) ?:
             ForInSimpleProgressionLoopGenerator.fromBoundedValueWithStepMinus1(codegen, forExpression, getBoundedValue(codegen))
+
+    private fun createConstBoundedForInReversedUntilGenerator(
+            codegen: ExpressionCodegen,
+            forExpression: KtForExpression
+    ): ForLoopGenerator? {
+        val endExpression = rangeCall.getReceiverExpression() ?: return null
+        return createConstBoundedForLoopGeneratorOrNull(
+                codegen, forExpression,
+                codegen.generateCallSingleArgument(rangeCall),
+                endExpression,
+                step = -1,
+                isStartInclusive = false
+        )
+    }
 }

compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntilWithNonConstBounds.kt

@@ -0,0 +1,31 @@
+// WITH_RUNTIME
+import kotlin.test.*
+
+fun intLow() = 1
+fun intHigh() = 5
+fun longLow() = 1L
+fun longHigh() = 5L
+fun charLow() = '1'
+fun charHigh() = '5'
+
+fun box(): String {
+    var sum = 0
+    for (i in (intLow() until intHigh()).reversed()) {
+        sum = sum * 10 + i
+    }
+    assertEquals(4321, sum)
+
+    var sumL = 0L
+    for (i in (longLow() until longHigh()).reversed()) {
+        sumL = sumL * 10 + i
+    }
+    assertEquals(4321L, sumL)
+
+    var sumC = 0
+    for (i in (charLow() until charHigh()).reversed()) {
+        sumC = sumC * 10 + i.toInt() - '0'.toInt()
+    }
+    assertEquals(4321, sumC)
+
+    return "OK"
+}

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -15318,6 +15318,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntil.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("forInReversedUntilWithNonConstBounds.kt")
+            public void testForInReversedUntilWithNonConstBounds() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntilWithNonConstBounds.kt");
+                doTest(fileName);
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/ranges/forInUntil")

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -15318,6 +15318,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntil.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("forInReversedUntilWithNonConstBounds.kt")
+            public void testForInReversedUntilWithNonConstBounds() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntilWithNonConstBounds.kt");
+                doTest(fileName);
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/ranges/forInUntil")

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

@@ -15318,6 +15318,12 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntil.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("forInReversedUntilWithNonConstBounds.kt")
+            public void testForInReversedUntilWithNonConstBounds() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntilWithNonConstBounds.kt");
+                doTest(fileName);
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/ranges/forInUntil")

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

@@ -16734,6 +16734,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntil.kt");
                 doTest(fileName);
             }
+
+            @TestMetadata("forInReversedUntilWithNonConstBounds.kt")
+            public void testForInReversedUntilWithNonConstBounds() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/ranges/forInReversed/forInReversedUntilWithNonConstBounds.kt");
+                doTest(fileName);
+            }
         }
 
         @TestMetadata("compiler/testData/codegen/box/ranges/forInUntil")