Skip to content

V
V8
Switch branch/tag
  1. 26 Jul, 2016 3 commits
    • bmeurer's avatar
      [turbofan] Fix overly aggressive dead code elimination. · 32346aae
      bmeurer authored 
      When we eliminate nodes during truncation analysis that have no value
uses, we must make sure that we do not eliminate speculative number
operations that would have side effects depending on the inputs, i.e.
for example a SpeculativeNumberMultiply(x,y) does ToNumber(x) and
ToNumber(y) first, so if either x or y could throw an exception during
ToNumber conversion, we must not eliminate the multiplication, even if
it has no value uses (some later pass may kill the actual machine
multiplication, but the checks on the inputs have to remain still).
So we check whether both x and y are PlainPrimitive, i.e. neither
Receiver nor Symbol, which could raise exceptions for ToNumber, and
only in that case we propagate the "unusedness" of the node to its
inputs.

This also uncovered a bug with the type of Dead, which must be None,
as this represents an impossible value, so we had to fix that too.

Also the dead code removal will not work correctly for constants (i.e.
pure nodes with no value inputs), as those might be cached and hence
we might resurrect them for an unrelated node lowering during
SimplifiedLowering and only later kill the actual node (replacing its
uses with Dead), which would then also replace the new use with Dead.
So that was fixed as well. This shouldn't change anything for the
result, as unused constants automagically disappear from the graph later
on anyways.

R=yangguo@chromium.org
BUG=chromium:631318

Review-Url: https://codereview.chromium.org/2182003002
Cr-Commit-Position: refs/heads/master@{#38038}
      32346aae
    • benwells's avatar
      Revert of MIPS: Fix '[turbofan] Prevent storing signalling NaNs into holey... · 73a5db9d
      benwells authored 
      Revert of MIPS: Fix '[turbofan] Prevent storing signalling NaNs into holey double arrays.' (patchset #2 id:20001 of https://codereview.chromium.org/2171303002/ )

Reason for revert:
This bug has an error in the toolchain.gypi file, the conditions clause is repeated. This has broken the DrMemory builder - see first failing chromium build https://build.chromium.org/p/chromium.memory.fyi/builders/Chromium%20Windows%20Builder%20%28DrMemory%29/builds/17857 which included a v8 roll.

For reference the errors are:
gyp: Key 'conditions' repeated at level 11 with key path 'target_defaults.conditions.6.1.target_conditions.0.1.conditions.0.1' while reading C:\b\build\slave\drm-cr\build\src\v8\gypfiles\toolchain.gypi while reading includes of C:\b\build\slave\drm-cr\build\src\v8\src\d8.gyp

gyp: Key 'conditions' repeated at level 11 with key path 'target_defaults.conditions.6.1.target_conditions.0.1.conditions.0.1' while reading C:\b\build\slave\drm-cr\build\src\v8\gypfiles\toolchain.gypi while reading includes of C:\b\build\slave\drm-cr\build\src\v8\src\v8.gyp

gyp: Key 'conditions' repeated at level 11 with key path 'target_defaults.conditions.6.1.target_conditions.0.1.conditions.0.1' while reading C:\b\build\slave\drm-cr\build\src\v8\gypfiles\toolchain.gypi while reading includes of C:\b\build\slave\drm-cr\build\src\v8\samples\samples.gyp

Original issue's description:
> MIPS: Fix '[turbofan] Prevent storing signalling NaNs into holey double arrays.'
>
> Port 6470ddad
>
> On MIPS different signaling NaN values must be used for hardware and simulator targets, even at snapshot generation when always simulator is used.
>
> Original commit message:
> This introduces SilenceNaN operator, which makes sure that we only
> store quiet NaNs into holey arrays. We omit the NaN silencing code
> at instruction selection time if the input is an operation that
> cannot possibly produce signalling NaNs.
>
> BUG=
>
> Committed: https://crrev.com/52f2ceb052f63324050c7a098e4398f510b54763
> Cr-Commit-Position: refs/heads/master@{#38030}

TBR=jarin@chromium.org,machenbach@google.com,akos.palfi@mattakis.com,ivica.bogosavljevic@imgtec.com,marija.antic@imgtec.com,ilija.pavlovic.imgtec@gmail.com,akos.palfi@imgtec.com,machenbach@chromium.org,balazs.kilvady@imgtec.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=

TBR=machenbach

Review-Url: https://codereview.chromium.org/2184573002
Cr-Commit-Position: refs/heads/master@{#38037}
      73a5db9d
    • v8-autoroll's avatar
      Update V8 DEPS. · 38764eac
      v8-autoroll authored 
      Rolling v8/build to cce24bcaab6481f479f4baf00b5ea36d78268bcd

Rolling v8/tools/mb to 11aa1bbe1b4fbae3694d14eb59b4eb98550bcbee

TBR=machenbach@chromium.org,vogelheim@chromium.org,hablich@chromium.org

Review-Url: https://codereview.chromium.org/2181913002
Cr-Commit-Position: refs/heads/master@{#38036}
      38764eac
  3. 25 Jul, 2016 37 commits