Rationale:
Finds general bounds on an induction variable by
looking at loop exits that use strict comparisons.
An intended client is bounds-check-elimination (AOT).
Change-Id: Icfd6481aad9669c15b78630e4322667cfce7c1ef
Reviewed-on: https://dart-review.googlesource.com/c/87485
Commit-Queue: Aart Bik <ajcbik@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Rationale:
Replacing the simple induction analysis in the range analyzer
with the new framework for finding induction variables removes
a lot of code and even saves some memory in the IR (for phis).
Note that this is only the first phase, i.e. using the new
framework for the same behavior in the range analyzer. In the
second phase, the new framework will be fully exploited to
compute more accurate ranges in many more cases.
Change-Id: Iae5bd5a155ef8592558b5bdb2388c5aa9da64e59
Reviewed-on: https://dart-review.googlesource.com/c/84500
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Aart Bik <ajcbik@google.com>
Rationale:
The more one knows about loops, the better!
This introduces a rigorous framework for detecting
induction variables (more precise "sequence" variables).
Even though this is already pretty general, in the
future we can expand this on a "need to" base, recognizing
more operators (shifts, negate, etc.) and more classes
of induction (perhaps geometric, polynomial, etc.).
Change-Id: I82a14515e8ae946d520ee470cd31046f6a58af7d
Reviewed-on: https://dart-review.googlesource.com/c/81743
Commit-Queue: Aart Bik <ajcbik@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Rationale:
Rather than relying on a separate loop detector, rely
on the new loop framework, which avoids code duplication
and ensures any improvement in loop detection/handling
will benefit this phase too. Note, most of the time, the
same loops are discovered with a few exceptions (which
is okay, since this is "just" heuristic usage). This CL
also simplifies loop detection a bit.
https://github.com/dart-lang/sdk/issues/34473
Change-Id: I1a1b19b99a698c74822473d2a1fe370287c1ade4
Reviewed-on: https://dart-review.googlesource.com/c/80523
Commit-Queue: Aart Bik <ajcbik@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Rationale:
Started a more structured implementation of detecting
loops and the loop hierarchy in the Dart flow graph.
This new framework can replace some of the more ad-hoc
approach taken now, as already started in this CL, and
also forms a foundation for more optimizations later.
https://github.com/dart-lang/sdk/issues/34473
Change-Id: I75130cb6863324910e3d068e4f2628c25fdf880c
Reviewed-on: https://dart-review.googlesource.com/c/79147
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
Commit-Queue: Aart Bik <ajcbik@google.com>
Martin Kustermann