tree 1593fb926606899b7a22399d12e24da5ec6fa018
parent cb90e3a29041ea55c4b5eb3d1477aa360381a1f1
author Aart Bik <ajcbik@google.com> 1510597877 -0800
committer Aart Bik <ajcbik@google.com> 1511210797 -0800

Recognize countable "break" loops

Rationale:
A particular break loop is generated by e.g. Kotlin
(or it can be expressed in Java as well) if the upper
(or lower) bound is inclusive, but a comparison test
would be too dangerous. The ART compiler often has
better range analysis (e.g. after inlining) to convert
such constructs back to countable loops, which are
more amenable to optimizations. For instance, we get
more than 200% improvement on the KotlinMicroLoops
benchmark, while close to 70 loops are recognized
in the Kotlin support library itself.

Bug: 67601686

Test: test-art-host test-art-target
Change-Id: I67e5c832df57e096efe2cf43a8579d9c10ca33e6