JVM_IR generate range-based loop closer to Java counter loop

KT-48435 KT-48507

compiler/testData/codegen/bytecodeText/forLoop/unsigned/stepNonConstOnNonLiteralProgression.kt

@@ -1,5 +1,15 @@
 // TARGET_BACKEND: JVM_IR
 // WITH_RUNTIME
+
+// IMPORTANT!
+// Please, when your changes cause failures in bytecodeText tests for 'for' loops,
+// examine the resulting bytecode shape carefully.
+// Range and progression-based loops generated with Kotlin compiler should be
+// as close as possible to Java counter loops ('for (int i = a; i < b; ++i) { ... }').
+// Otherwise it may result in performance regression due to missing HotSpot optimizations.
+// Run Kotlin compiler benchmarks (https://github.com/Kotlin/kotlin-benchmarks)
+// with compiler built from your changes if you are not sure.
+
 fun one() = 1
 
 fun box(): String {
@@ -13,28 +23,6 @@ fun box(): String {
 // For "step" progressions in JVM IR, a call to getProgressionLastElement() is made to compute the "last" value.
 // If "step" is called on a non-literal progression, there is a check to see if that progression's step value is < 0.
 // If the step is non-constant, there is a check that it is > 0, and if not, an IllegalArgumentException is thrown.
-//
-// Expected lowered form of loop:
-//
-//   // Additional statements:
-//   val nestedFirst = uintProgression.first
-//   val nestedLast = uintProgression.last
-//   val nestedStep = uintProgression.step
-//   var stepArg = one()
-//   if (stepArg <= 0) throw IllegalArgumentException("Step must be positive, was: $stepArg.")
-//   if (nestedStep <= 0) stepArg = -stepArg
-//
-//   // Standard form of loop over progression
-//   var inductionVar = nestedFirst
-//   val last = getProgressionLastElement(nestedFirst, nestedLast, stepArg)
-//   if ((stepArg > 0 && inductionVar <= last) || (stepArg < 0 && last <= inductionVar)) {
-//     // Loop is not empty
-//     do {
-//       val i = inductionVar
-//       inductionVar += stepArg
-//       // Loop body
-//     } while (i != last)
-//   }
 
 // 0 iterator
 // 0 getStart
@@ -47,10 +35,15 @@ fun box(): String {
 // 1 ATHROW
 // 2 INVOKESTATIC kotlin/UnsignedKt.uintCompare
 // 3 IFGT
-// 1 IF_ICMPNE
+// 1 IF_ICMPEQ
 // 2 IFLE
 // 1 IFGE
 // 7 IF
 // 1 INEG
 // 0 INVOKESTATIC kotlin/UInt.constructor-impl
 // 0 INVOKE\w+ kotlin/UInt.(un)?box-impl
+// 25 ILOAD
+// 15 ISTORE
+// 1 IADD
+// 0 ISUB
+// 0 IINC