This adds a simple counter to Turbofan that's incremented throughout the compilation, hopefully
frequently enough so we can use it to detect divergence and performance bugs.
In addition, we assert that this counter never gets too high. That's the equivalent of a simple
timeout, just more deterministic. The limitations on Turbofan input size should guarantee that
we never exceed this limit. Since we probably do exceed it rarely, this check is only a DCHECK and
intended to detect performance and divergence issues, but not supposed to be performed in release
builds.
In addition, this CL adds UMA stats to observe the real world distribution of the tick measurement.
Bug: v8:9444
Change-Id: I182dac6ecac64715e3f5885ff5c7c17549351cd0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1695475
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62754}
There's no ambiguity and the shorter name makes things easier to read.
Bug: v8:7790
Change-Id: Ibcf3fd7f38a91e26a83cd335fad0ec80a5fe9be1
Reviewed-on: https://chromium-review.googlesource.com/c/1278392
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56623}
This is just a cleanup.
Bug: v8:7790
Change-Id: Ic0114451159b8c504f527f3cf3bdaed6a8cc8741
Reviewed-on: https://chromium-review.googlesource.com/1243103
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56206}
As a first step towards moving accesses to the broker, this moves
heap accesses from BitsetType::Lub to the broker.
Bug: v8:7790
Change-Id: Ie240b84b979717caae42cb8aa06ee8d9877a446d
Reviewed-on: https://chromium-review.googlesource.com/1088695
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53571}
This also includes the precise reducer name. Currently the information
is available in the node tooltip in turbolizer. The new shortcut 's' in
the graph view selects the nodes the currently selected nodes were created
from.
Bug: v8:7327
Change-Id: I7ca7327d0cfa112972e3567df6e4a223c8eff3c0
Reviewed-on: https://chromium-review.googlesource.com/1064059
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53258}
The idea is to mark all the branches and loads participating in array
bounds checks, and let them contribute-to/use the poisoning register.
In the code, the marks for array indexing operations now contain
"Critical" in their name. By default (--untrusted-code-mitigations),
we only instrument the "critical" operations with poisoning.
With that in place, we also remove the array masking approach based
on arithmetic.
Since we do not propagate the poison through function calls,
we introduce a node for poisoning an index that is passed through
function call - the typical example is the bounds-checked index
that is passed to the CharCodeAt builtin.
Most of the code in this CL is threads through the three levels of
protection (safe, critical, unsafe) for loads, branches and flags.
Bug: chromium:798964
Change-Id: Ief68e2329528277b3ba9156115b2a6dcc540d52b
Reviewed-on: https://chromium-review.googlesource.com/995413
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52883}
If a NumberConstant can be represented as a Smi, then lower it to a
IntPtrConstant node during simplified lowering. Thanks to this, all backends can
match Smi values that can also be encoded as immediates in the instruction
selector. Additionally, we can apply the same lowering to the CodeAssembler for
the snapshot.
As a result, we can remove `mov` instructions generated because Int32Matcher and
Int64Matcher didn't not recognize Smis:
For 32-bit target, it's common for Smis also be immediates: "if (a < 100) {}"
~~~
mov r1, #200 -> cmp r0, #200
cmp r0, r1 -> blt <>
blt <> ->
~~~
On Arm64 particularly, we lose opportunites to use `cbz`: "if (a == 0) {}"
~~~
movz x0, #0x0 -> cbz x1 <>
cmp x1, x0 ->
b.eq <> ->
~~~
Overall, we do not see an impact on benchmarks such as webtooling. However, we
do see noteworthy code size reduction, from 0.5% to 1.5%.
Bug:
Change-Id: I7fbb718ad51b9036c3514fa31c1326bdd6f2b0e6
Reviewed-on: https://chromium-review.googlesource.com/848814
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#50569}
