This is a large patch that contains all of the core changes for
renderroot splitting.
Differential Revision: https://phabricator.services.mozilla.com/D20701
--HG--
extra : moz-landing-system : lando
This is a large patch that contains all of the core changes for
renderroot splitting.
Differential Revision: https://phabricator.services.mozilla.com/D20701
--HG--
extra : moz-landing-system : lando
We already take steps in `IndexOf` to avoid bounds checks--by using
direct pointer accesses--and we should do the same thing for binary
searches as well.
In many places, nsTArray::IndexOf is followed by accessing that element
(hopefully with `Elements() + index`, which skips unnecessary bounds checks.)
But this pattern introduces operations that could be avoided:
- IndexOf converts the address of the found element into an index,
- The caller must test for a special `NoIndex` value,
- On success, accesses convert that index back into the original address.
This patch introduces new 'ApplyIf...' functions that combine all these
operations in a more efficient ensemble: If the sought element is found, it is
passed by reference to a given callable object (usually a lambda); if not
found, another callable is invoked.
Depending on what they need, the first callable may take one of these parameter
lists: (), (size_t), (maybe-const elem_type&), (size_t, maybe-const elem_type&).
On top of removing the pointer->index->pointer operations in most cases,
invoking callables directly from ApplyIf is safer, as the array is guaranteed to
be untouched at this time.
Also, being templates taking function objects, in most cases the compiler should
be able to inline and optimize the search and its callables' code.
This patch gives example uses in nsTArray::Contains, and in
FrameProperties::GetInternal, SetInternal.
And FrameProperties::Has now calls Contains, which is more efficient because
the former code would compute an index (or NoIndex), and then convert that index
to a bool; whereas the new code directly produces a bool from within the search
algorithm.
Differential Revision: https://phabricator.services.mozilla.com/D2758
--HG--
extra : moz-landing-system : lando
When removing an element that exists in the array, there's no need to
perform extra bounds checks for actually removing the element; the
presence of the element guarantees that we have a valid index and a
valid range to remove. So split RemoveElementsAt into a safe interface
and an unsafe interface, and let RemoveElement call the latter as an
internal optimization. The same logic applies to RemoveElementSorted.
We call RemoveElement depressingly often, so this is a nice little win.
Same approach as the other bug, mostly replacing automatically by removing
'using mozilla::Forward;' and then:
s/mozilla::Forward/std::forward/
s/Forward</std::forward</
The only file that required manual fixup was TestTreeTraversal.cpp, which had
a class called TestNodeForward with template parameters :)
MozReview-Commit-ID: A88qFG5AccP
This was done automatically replacing:
s/mozilla::Move/std::move/
s/ Move(/ std::move(/
s/(Move(/(std::move(/
Removing the 'using mozilla::Move;' lines.
And then with a few manual fixups, see the bug for the split series..
MozReview-Commit-ID: Jxze3adipUh
When this was added, the xpcom glue was still a thing, and there was a
distinction between things that would build with mozalloc available and
others. There is no such distinction anymore. Anything that has access
to xpcom has access to infallible allocator functions.
--HG--
extra : rebase_source : 04bce114e940c53709275d0354ea7240df4a051e
nsTArray::AppendElement{,s} uses an IncrementLength method to adjust the
length of the array after appending elements. There are checks in
IncrementLength to ensure that we're not incrementing the length stored
in the static empty header object; these checks are necessary in cases
such as appending a zero-length array to another zero-length array.
But we do not need this check when we're calling AppendElement: we know
the header is obviously not the empty header, because we increased the
length of the array by one for the newly appended element. Incrementing
the length can therefore be inlined, saving ~90K of codesize on x86-64
Linux.
This adds release bounds checking to ReplaceElementsAt, InsertElementAt, and
InsertElementsAt to make sure the insertion point is within the current array
bounds.
MozReview-Commit-ID: 1pFr8LuOROI
Barret Rennie
Sylvestre Ledru
Csoregi Natalia
Narcis Beleuzu
Cameron McCormack
Ciure Andrei
Jon Coppeard
Doug Thayer
Nathan Froyd
Ehsan Akhgari
Gerald Squelart
Nika Layzell
Cosmin Sabou
Brindusan Cristian
Kris Maglione
Andreea Pavel
Andi-Bogdan Postelnicu
Emilio Cobos Álvarez
Markus Stange
Sebastian Hengst
Tristan Bourvon
Bas Schouten
Andrew McCreight
Miko Mynttinen
Daniel Holbert
Adrian Wielgosik
Mike Hommey
Boris Zbarsky
Eric Rahm
Henri Sivonen