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kotlin/compiler/testData/codegen/bytecodeText/forLoop/primitiveProgression.kt

62 lines
1.6 KiB
Kotlin
Vendored

fun f() {
for (i in 0..5 step 2) {
}
// JVM non-IR: `step 1` suppresses optimized code generation for 'for-in-downTo'
// JVM IR: No getProgressionLastElement() call required for `step 1`, equivalent to `5 downTo 1`
for (i in 5 downTo 1 step 1) {
}
}
// JVM non-IR does NOT specifically handle "step" progressions. The stepped progressions in the above code are constructed and their
// first/last/step properties are retrieved.
// JVM IR has an optimized handler for "step" progressions and elides the construction of the stepped progressions.
//
// Expected lowered form of `for (i in 0..5 step 2)`:
//
// // Standard form of loop over progression
// var inductionVar = 0
// val last = getProgressionLastElement(0, 5, 2)
// val step = 2
// if (inductionVar <= last) {
// // Loop is not empty
// do {
// val i = inductionVar
// inductionVar += step
// // Loop body
// } while (i != last)
// }
//
// Expected lowered form of `for (i in 5 downTo 1 step 1)`:
//
// // Standard form of loop over progression
// var inductionVar = 5
// val last = 1
// val step = -1
// if (last <= inductionVar) { // Optimized out in bytecode
// // Loop is not empty
// do {
// val i = inductionVar
// inductionVar += step
// // Loop body
// } while (last <= inductionVar)
// }
// 0 iterator
// JVM_TEMPLATES
// 2 getFirst
// 2 getLast
// 2 getStep
// JVM_IR_TEMPLATES
// 0 getStart
// 0 getEnd
// 0 getFirst
// 0 getLast
// 0 getStep
// 1 IF_ICMPGT
// 1 IF_ICMPNE
// 1 IF_ICMPLE
// 3 IF
// 1 INVOKESTATIC kotlin/internal/ProgressionUtilKt.getProgressionLastElement \(III\)I