last-exclusive progressions (i.e., "until" progressions and loop over
array indices).
This change makes it possible to correctly implement the handling of
"step" progressions. Computing the last element of a stepped progression
requires that the last is inclusive.
Also invert the while loop (into if + do-while) that is used when
lowering for-loops over progressions that cannot overflow. This keeps
the performance characteristics closer to the ForLoopsLowering in
kotlin-native, since the goal is to converge to this shared version.
Also used IrType instead of KotlinType, where possible.
https://github.com/JetBrains/kotlin/pull/2390https://github.com/JetBrains/kotlin/pull/2305
do-while with enclosing "not empty" check).
Also do not add additional "not empty" condition for `until` loops when
the given bound is a constant != MIN_VALUE.
non-specialized progressions, including "step" progressions.
DefaultProgressionHandler uses the "first/last/step" properties of
the progression when building the loop header.
Also deleted StepHandler. Since the HeaderInfo.needLastCalculation is
only set to true for handling step progressions, deleted that property
and all associated logic around it.
