More specifically on 64-bit platforms, when other heuristic fail:
- in AOT mode unbox all int typed phis.
- in JIT mode unbox all non-Smi int typed phis i.e. mixed
Mint/Smi phis.
This brings treatment of int phis closer to how we treat other
boxed phis.
This considerably improves AOT code quality for loops which
our current conservative heuristic does not currently hit,
for example:
void foo(int start, int end) {
for (var i = start; i < end; i++) {
}
}
Code like this would use a boxed Phi previously which does not make
sense.
In JIT mode to really benefit from aggressive unboxing we
might need to shift from over-reliance on Smi operations, e.g.
when phi is unboxed we want to cascade that through and unbox
operations which are performed on it transitively. This requires
much more sophisticated algorithm and is outside of scope for this
change.
In AOT we in general treat all arithmetic operations as operations
over 64-bit int values so unboxing phis makes more sense.
As a result of this change we see small improvement in code size:
flutter_gallery_app_so_gzip_size -0.2392%
TEST=ci
Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try
Change-Id: Iae9a16f353e53f649da4e665d2812ad47099a674
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/187860
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
After constant propagation is performed on the callee function body
during inlining, there are extra opportunities for specializing
calls. Unspecialized calls are not inlined, so it is important to
specialize those calls during inlining to open further opportunities
for inlining.
With this extra pass inliner is able to inline get:length after
specializing inlined List.generate constructor, and eliminate
bounds check from the initialization loop.
This change improves micro-benchmark creating 100,000 lists using
List<int>.generate(1000, (int x) => x, growable: false);
in AOT mode on x64 from 308ms to 167ms.
This makes it on par with pre-NNBD fixed-size list initialization:
var result = List<int>(1000);
for (var i = 0; i < 1000; i++) {
result[i] = i;
}
In fact, after all optimizations final flow graph (and generated
code) for List.generate and explicit loop become very similar.
This change has no effect on Flutter gallery size in release mode.
Issue: https://github.com/dart-lang/sdk/issues/42283
Change-Id: I3566386608733226e1c11cb5d6892cd869e564d7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/151466
Commit-Queue: Vyacheslav Egorov <vegorov@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
In cases where the same target function is used for multiple
CID ranges, we only perform the inlining once. However, if the
CID range used for the initial inlining is a single CID, we will
set the type of the redefinition to that CID.
Detect this case and clear the concrete type associated with
the redefinition if it was given one.
Change-Id: I9f9bdd7c21e0dc1ac537f8facece0010630bd9aa
Cq-Include-Trybots: luci.dart.try:vm-kernel-win-debug-x64-try,vm-kernel-win-release-ia32-try,vm-kernel-win-product-x64-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/105221
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
In cases where the same target function is used for multiple
CID ranges, we only perform the inlining once. However, if the
CID range used for the initial inlining is a single CID, we will
set the type of the redefinition to that CID.
Detect this case and clear the concrete type associated with
the redefinition if it was given one.
Change-Id: I3c27c46c71e10e71624ce3b969cb741eb9b2915f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/104781
Commit-Queue: Teagan Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Ryan Macnak