Files
kotlin-fork/compiler/testData/codegen/bytecodeText/forLoop/stepped/stepNonConst.kt
T
Mark Punzalan b1ce21bc55 ForLoopsLowering: Reduce unnecessary temporary variables for the
"checked step" (check for a positive step arg) and "negated step"
(negate the step arg when the nested step is negative).
2020-07-22 22:32:29 +02:00

44 lines
1.1 KiB
Kotlin
Vendored

// TARGET_BACKEND: JVM_IR
fun one() = 1
fun box(): String {
for (i in 1..7 step one()) {
}
return "OK"
}
// For "step" progressions in JVM IR, a call to getProgressionLastElement() is made to compute the "last" value.
// 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:
// var stepArg = one()
// if (stepArg <= 0) throw IllegalArgumentException("Step must be positive, was: $stepArg.")
//
// // Standard form of loop over progression
// var inductionVar = 1
// val last = getProgressionLastElement(1, 7, stepArg)
// if (inductionVar <= last) {
// // Loop is not empty
// do {
// val i = inductionVar
// inductionVar += stepArg
// // Loop body
// } while (i != last)
// }
// 0 iterator
// 0 getStart
// 0 getEnd
// 0 getFirst
// 0 getLast
// 0 getStep
// 1 INVOKESTATIC kotlin/internal/ProgressionUtilKt.getProgressionLastElement
// 1 NEW java/lang/IllegalArgumentException
// 1 ATHROW
// 1 IF_ICMPGT
// 1 IF_ICMPNE
// 1 IFGT
// 3 IF