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[turbofan] Ignore pretenure flag for JSCreateClosure.

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As part of https://chromium-review.googlesource.com/902283 I changed the
JSCreateClosure lowering to respect the pretenure flag on the operator,
but that tanks some benchmarks heavily, as the Parser marks closures
like

  args[l] = function(...) { ... }

for old-space allocation, which backfires for short-living closures.

Bug: v8:7253, chromium:810132
Change-Id: I66f048553d9f2a70b2691537e726128f3fb01563
Reviewed-on: https://chromium-review.googlesource.com/910849
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51203}
This commit is contained in:
Benedikt Meurer 2018-02-09 10:41:28 +01:00 committed by Commit Bot
parent c19b7703a1
commit 8b8e353ca1
1 changed files with 12 additions and 1 deletions
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13
src/compiler/js-create-lowering.cc
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@ -928,10 +928,21 @@ Reduction JSCreateLowering::ReduceJSCreateClosure(Node* node) {
DCHECK(!function_map->IsInobjectSlackTrackingInProgress());
DCHECK(!function_map->is_dictionary_map());
// TODO(turbofan): We should use the pretenure flag from {p} here,
// but currently the heuristic in the parser works against us, as
// it marks closures like
//
// args[l] = function(...) { ... }
//
// for old-space allocation, which doesn't always make sense. For
// example in case of the bluebird-parallel benchmark, where this
// is a core part of the *promisify* logic (see crbug.com/810132).
PretenureFlag pretenure = NOT_TENURED;
// Emit code to allocate the JSFunction instance.
STATIC_ASSERT(JSFunction::kSizeWithoutPrototype == 7 * kPointerSize);
AllocationBuilder a(jsgraph(), effect, control);
a.Allocate(function_map->instance_size(), p.pretenure(), Type::Function());
a.Allocate(function_map->instance_size(), pretenure, Type::Function());
a.Store(AccessBuilder::ForMap(), function_map);
a.Store(AccessBuilder::ForJSObjectPropertiesOrHash(),
jsgraph()->EmptyFixedArrayConstant());