Optimize range operations for 'until' extension from stdlib (KT-9900)

NB: for-in-until loop is generated as precondition loop, because the
corresponding range is right-exclusive (and thus we have no problems
with integer overflows).

compiler/backend/src/org/jetbrains/kotlin/codegen/RangeCodegenUtil.java

@@ -134,6 +134,17 @@ public static boolean isPrimitiveNumberDownTo(@NotNull CallableDescriptor descri
         return true;
     }
 
+    public static boolean isPrimitiveNumberUntil(@NotNull CallableDescriptor descriptor) {
+        if (!isTopLevelInPackage(descriptor, "until", "kotlin.ranges")) return false;
+
+        ReceiverParameterDescriptor extensionReceiver = descriptor.getExtensionReceiverParameter();
+        if (extensionReceiver == null) return false;
+        ClassifierDescriptor extensionReceiverClassifier = extensionReceiver.getType().getConstructor().getDeclarationDescriptor();
+        if (!isPrimitiveNumberClassDescriptor(extensionReceiverClassifier)) return false;
+
+        return true;
+    }
+
     public static boolean isArrayOrPrimitiveArrayIndices(@NotNull CallableDescriptor descriptor) {
         if (!isTopLevelInPackage(descriptor, "indices", "kotlin.collections")) return false;
 

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/AbstractForInRangeLoopGenerator.kt

@@ -66,9 +66,13 @@ abstract class AbstractForInRangeLoopGenerator : AbstractForInProgressionOrRange
 
     override fun assignToLoopParameter() {}
 
-    override fun increment(loopExit: Label) {
+    override fun checkPostConditionAndIncrement(loopExit: Label) {
         checkPostCondition(loopExit)
 
+        incrementLoopVariable()
+    }
+
+    protected fun incrementLoopVariable() {
         if (loopParameterType === Type.INT_TYPE) {
             v.iinc(loopParameterVar, step)
         }

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/AbstractForLoopGenerator.kt

@@ -116,7 +116,7 @@ abstract class AbstractForLoopGenerator(
 
     protected abstract fun assignToLoopParameter()
 
-    protected abstract fun increment(loopExit: Label)
+    protected abstract fun checkPostConditionAndIncrement(loopExit: Label)
 
     fun body() {
         codegen.generateLoopBody(forExpression.body)
@@ -135,7 +135,7 @@ abstract class AbstractForLoopGenerator(
     fun afterBody(loopExit: Label) {
         codegen.markStartLineNumber(forExpression)
 
-        increment(loopExit)
+        checkPostConditionAndIncrement(loopExit)
 
         v.mark(bodyEnd)
     }

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/ForInArrayLoopGenerator.kt

@@ -74,7 +74,7 @@ class ForInArrayLoopGenerator(codegen: ExpressionCodegen, forExpression: KtForEx
         v.store(loopParameterVar, asmElementType)
     }
 
-    override fun increment(loopExit: Label) {
+    override fun checkPostConditionAndIncrement(loopExit: Label) {
         v.iinc(indexVar, 1)
     }
 }

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/ForInCharSequenceLoopGenerator.kt

@@ -67,7 +67,7 @@ class ForInCharSequenceLoopGenerator(codegen: ExpressionCodegen, forExpression:
         v.store(loopParameterVar, asmElementType)
     }
 
-    override fun increment(loopExit: Label) {
+    override fun checkPostConditionAndIncrement(loopExit: Label) {
         v.iinc(indexVar, 1)
     }
 

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/ForInProgressionExpressionLoopGenerator.kt

@@ -92,7 +92,7 @@ class ForInProgressionExpressionLoopGenerator(codegen: ExpressionCodegen, forExp
 
     override fun assignToLoopParameter() {}
 
-    override fun increment(loopExit: Label) {
+    override fun checkPostConditionAndIncrement(loopExit: Label) {
         checkPostCondition(loopExit)
 
         val loopParameter = loopParameter()

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/ForInUntilRangeLoopGenerator.kt

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.codegen.forLoop
+
+import org.jetbrains.kotlin.codegen.ExpressionCodegen
+import org.jetbrains.kotlin.codegen.StackValue
+import org.jetbrains.kotlin.psi.KtExpression
+import org.jetbrains.kotlin.psi.KtForExpression
+import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
+import org.jetbrains.kotlin.resolve.scopes.receivers.ReceiverValue
+import org.jetbrains.org.objectweb.asm.Label
+import org.jetbrains.org.objectweb.asm.Type
+
+class ForInUntilRangeLoopGenerator(
+        codegen: ExpressionCodegen,
+        forExpression: KtForExpression,
+        loopRangeCall: ResolvedCall<*>
+) : AbstractForInRangeLoopGenerator(codegen, forExpression) {
+    private val from: ReceiverValue = loopRangeCall.extensionReceiver!!
+    private val to: KtExpression = ExpressionCodegen.getSingleArgumentExpression(loopRangeCall)!!
+
+    override fun storeRangeStartAndEnd() {
+        loopParameter().store(codegen.generateReceiverValue(from, false), v)
+        StackValue.local(endVar, asmElementType).store(codegen.gen(to), v)
+    }
+
+    override fun checkEmptyLoop(loopExit: Label) {}
+
+    override fun checkPreCondition(loopExit: Label) {
+        loopParameter().put(asmElementType, v)
+        v.load(endVar, asmElementType)
+        if (asmElementType.sort == Type.LONG) {
+            v.lcmp()
+            v.ifge(loopExit)
+        }
+        else {
+            v.ificmpge(loopExit)
+        }
+    }
+
+    override fun checkPostConditionAndIncrement(loopExit: Label) {
+        incrementLoopVariable()
+    }
+}

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/ForLoopGenerators.kt

@@ -68,6 +68,8 @@ private fun ExpressionCodegen.createOptimizedForLoopGeneratorOrNull(
             ForInRangeLiteralLoopGenerator(this, forExpression, loopRangeCall)
         RangeCodegenUtil.isPrimitiveNumberDownTo(loopRangeCallee) ->
             ForInDownToProgressionLoopGenerator(this, forExpression, loopRangeCall)
+        RangeCodegenUtil.isPrimitiveNumberUntil(loopRangeCallee) ->
+            ForInUntilRangeLoopGenerator(this, forExpression, loopRangeCall)
         RangeCodegenUtil.isArrayOrPrimitiveArrayIndices(loopRangeCallee) ->
             ForInArrayIndicesRangeLoopGenerator(this, forExpression, loopRangeCall)
         RangeCodegenUtil.isCollectionIndices(loopRangeCallee) ->

compiler/backend/src/org/jetbrains/kotlin/codegen/forLoop/IteratorForLoopGenerator.kt

@@ -83,5 +83,5 @@ class IteratorForLoopGenerator(codegen: ExpressionCodegen, forExpression: KtForE
         StackValue.local(loopParameterVar, loopParameterType).store(value, v)
     }
 
-    override fun increment(loopExit: Label) {}
+    override fun checkPostConditionAndIncrement(loopExit: Label) {}
 }

compiler/testData/codegen/box/ranges/forInUntil/forInUntilChar.kt

@@ -0,0 +1,28 @@
+// IGNORE_BACKEND: JS
+// see KT-17700
+
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    testChar()
+    testNullableChar()
+    return "OK"
+}
+
+private fun testChar() {
+    var sum = ""
+    for (ch in '1' until '5') {
+        sum = sum + ch
+    }
+    assertEquals("1234", sum)
+}
+
+private fun testNullableChar() {
+    var sum = ""
+    for (ch: Char? in '1' until '5') {
+        sum = sum + (ch ?: break)
+    }
+    assertEquals("1234", sum)
+}

compiler/testData/codegen/box/ranges/forInUntil/forInUntilChar0.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    for (ch in (-10).toChar() until '\u0000') {
+        throw AssertionError("This loop shoud not be executed")
+    }
+    return "OK"
+}

compiler/testData/codegen/box/ranges/forInUntil/forInUntilInt.kt

@@ -0,0 +1,25 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    testIntInIntUntilInt()
+    testNullableIntInIntUntilInt()
+    return "OK"
+}
+
+private fun testIntInIntUntilInt() {
+    var sum = 0
+    for (i in 1 until 5) {
+        sum = sum * 10 + i
+    }
+    assertEquals(1234, sum)
+}
+
+private fun testNullableIntInIntUntilInt() {
+    var sum = 0
+    for (i: Int? in 1 until 5) {
+        sum = sum * 10 + (i?.toInt() ?: break)
+    }
+    assertEquals(1234, sum)
+}

compiler/testData/codegen/box/ranges/forInUntil/forInUntilLesserInt.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    for (i in 10 until 0) {
+        throw AssertionError("This loop should not be executed")
+    }
+    return "OK"
+}

compiler/testData/codegen/box/ranges/forInUntil/forInUntilLong.kt

@@ -0,0 +1,43 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun testLongInLongUntilLong() {
+    var sum = 0
+    for (i in 1L until 5L) {
+        sum = sum * 10 + i.toInt()
+    }
+    assertEquals(1234, sum)
+}
+
+fun testLongInLongUntilInt() {
+    var sum = 0
+    for (i in 1L until 5.toInt()) {
+        sum = sum * 10 + i.toInt()
+    }
+    assertEquals(1234, sum)
+}
+
+fun testLongInIntUntilLong() {
+    var sum = 0
+    for (i in 1.toInt() until 5L) {
+        sum = sum * 10 + i.toInt()
+    }
+    assertEquals(1234, sum)
+}
+
+fun testNullableLongInIntUntilLong() {
+    var sum = 0
+    for (i: Long? in 1.toInt() until 5L) {
+        sum = sum * 10 + (i?.toInt() ?: break)
+    }
+    assertEquals(1234, sum)
+}
+
+fun box(): String {
+    testLongInLongUntilLong()
+    testLongInIntUntilLong()
+    testLongInLongUntilInt()
+    testNullableLongInIntUntilLong()
+    return "OK"
+}

compiler/testData/codegen/box/ranges/forInUntil/forInUntilMaxint.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    for (i in Int.MAX_VALUE until Int.MAX_VALUE) {
+        throw AssertionError("This loop shoud not be executed")
+    }
+    return "OK"
+}

compiler/testData/codegen/box/ranges/forInUntil/forInUntilMinint.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    for (i in 0 until Int.MIN_VALUE) {
+        throw AssertionError("This loop shoud not be executed")
+    }
+    return "OK"
+}

compiler/testData/codegen/box/ranges/forInUntil/forInUntilMinlong.kt

@@ -0,0 +1,10 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    for (i in 0 until Long.MIN_VALUE) {
+        throw AssertionError("This loop shoud not be executed")
+    }
+    return "OK"
+}

compiler/testData/codegen/box/ranges/forInUntil/forIntInIntUntilSmartcastInt.kt

@@ -0,0 +1,21 @@
+// WITH_RUNTIME
+
+import kotlin.test.assertEquals
+
+fun box(): String {
+    testIntInIntUntilSmartcastInt()
+    return "OK"
+}
+
+private fun testIntInIntUntilSmartcastInt() {
+    var sum = 0
+
+    val a: Any = 5
+    if (a is Int) {
+        for (i: Int in 1 until a) {
+            sum = sum * 10 + i
+        }
+    }
+
+    assertEquals(1234, sum)
+}

compiler/testData/codegen/bytecodeText/forLoop/forInUntil.kt

@@ -0,0 +1,16 @@
+// WITH_RUNTIME
+
+fun test(): Int {
+    var sum = 0
+    for (i in 1 until 6) {
+        sum = sum * 10 + i
+    }
+    return sum
+}
+
+// 0 iterator
+// 0 getStart
+// 0 getEnd
+// 0 getFirst
+// 0 getLast
+// 1 IF

compiler/testData/codegen/bytecodeText/intRangeNoBoxing.kt

@@ -1,6 +1,7 @@
 fun Int.until(other: Int) = this..other - 1
 fun foo() {
-    for (i in 1 until 2) {
+    val range = 1 until 2
+    for (i in range) {
     }
 
     for (i in 1..2 step 4) {}