From fdbcb64d398f78bf396480f3f93a47f3ec47db18 Mon Sep 17 00:00:00 2001
From: Xin Wang <scaventz@outlook.com>
Date: Tue, 25 Jan 2022 23:06:49 +0800
Subject: [PATCH] JVM_IR: frame optimization for cast to IntProgression

#KT-29199
---
 .../optimization/boxing/BoxingInterpreter.kt     | 16 +++++++++++++++-
 .../codegen/FirBytecodeTextTestGenerated.java    |  6 ++++++
 .../codegen/bytecodeText/mergedProgression.kt    |  7 +++++++
 .../codegen/IrBytecodeTextTestGenerated.java     |  6 ++++++
 4 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 compiler/testData/codegen/bytecodeText/mergedProgression.kt

diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.kt b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.kt
index 30f8992f0f6..5b18f7bd2bb 100644
--- a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.kt
+++ b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.kt
@@ -35,6 +35,7 @@ import org.jetbrains.org.objectweb.asm.Type
 import org.jetbrains.org.objectweb.asm.tree.AbstractInsnNode
 import org.jetbrains.org.objectweb.asm.tree.InsnList
 import org.jetbrains.org.objectweb.asm.tree.MethodInsnNode
+import org.jetbrains.org.objectweb.asm.tree.TypeInsnNode
 import org.jetbrains.org.objectweb.asm.tree.analysis.BasicValue
 
 open class BoxingInterpreter(
@@ -136,7 +137,10 @@ open class BoxingInterpreter(
     override fun unaryOperation(insn: AbstractInsnNode, value: BasicValue): BasicValue? {
         checkUsedValue(value)
 
-        return if (insn.opcode == Opcodes.CHECKCAST && isExactValue(value))
+        return if (insn.opcode == Opcodes.CHECKCAST
+            && isExactValue(value)
+            && !isCastToProgression(insn) // operations such as cast kotlin/ranges/IntRange to kotlin/ranges/IntProgression, should be allowed
+        )
             value
         else
             super.unaryOperation(insn, value)
@@ -147,6 +151,16 @@ open class BoxingInterpreter(
                 value is CleanBoxedValue ||
                 value.type != null && isProgressionClass(value.type)
 
+    private fun isCastToProgression(insn: AbstractInsnNode): Boolean {
+        assert(insn.opcode == Opcodes.CHECKCAST) { "Expected opcode Opcodes.CHECKCAST, but ${insn.opcode} found" }
+        val desc = (insn as TypeInsnNode).desc
+        return desc in setOf(
+            "kotlin/ranges/CharProgression",
+            "kotlin/ranges/IntProgression",
+            "kotlin/ranges/LongProgression"
+        )
+    }
+
     override fun merge(v: BasicValue, w: BasicValue) =
         mergeStackValues(v, w)
 
diff --git a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBytecodeTextTestGenerated.java b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBytecodeTextTestGenerated.java
index 91e194203cf..2fc1f051761 100644
--- a/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBytecodeTextTestGenerated.java
+++ b/compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBytecodeTextTestGenerated.java
@@ -367,6 +367,12 @@ public class FirBytecodeTextTestGenerated extends AbstractFirBytecodeTextTest {
         runTest("compiler/testData/codegen/bytecodeText/maxStackAfterOptimizations.kt");
     }
 
+    @Test
+    @TestMetadata("mergedProgression.kt")
+    public void testMergedProgression() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeText/mergedProgression.kt");
+    }
+
     @Test
     @TestMetadata("noAccessorForProtectedInSamePackageCrossinline.kt")
     public void testNoAccessorForProtectedInSamePackageCrossinline() throws Exception {
diff --git a/compiler/testData/codegen/bytecodeText/mergedProgression.kt b/compiler/testData/codegen/bytecodeText/mergedProgression.kt
new file mode 100644
index 00000000000..fbfd9e4bcea
--- /dev/null
+++ b/compiler/testData/codegen/bytecodeText/mergedProgression.kt
@@ -0,0 +1,7 @@
+// TARGET_BACKEND: JVM_IR
+
+fun test(a: Int, b: Int, flag: Boolean) =
+    (if (flag) a..b else a downTo b).map { it + 1 }
+
+// 0 java/util/Iterator.next \(\)Ljava/lang/Object;
+// 1 kotlin/collections/IntIterator.nextInt \(\)I
diff --git a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBytecodeTextTestGenerated.java b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBytecodeTextTestGenerated.java
index 9fc2223c142..9cf47372f2c 100644
--- a/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBytecodeTextTestGenerated.java
+++ b/compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBytecodeTextTestGenerated.java
@@ -367,6 +367,12 @@ public class IrBytecodeTextTestGenerated extends AbstractIrBytecodeTextTest {
         runTest("compiler/testData/codegen/bytecodeText/maxStackAfterOptimizations.kt");
     }
 
+    @Test
+    @TestMetadata("mergedProgression.kt")
+    public void testMergedProgression() throws Exception {
+        runTest("compiler/testData/codegen/bytecodeText/mergedProgression.kt");
+    }
+
     @Test
     @TestMetadata("noAccessorForProtectedInSamePackageCrossinline.kt")
     public void testNoAccessorForProtectedInSamePackageCrossinline() throws Exception {