Currently we avoid checking for the hole value after array loads, if the
result is only used by instructions that definitely deoptimize in case
of the hole value (HChange instructions).
This change performs the same procedure for loading from deleteable/read-only
global variable where we can also avoid the check in the same cases.
Review URL: http://codereview.chromium.org/8054008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9453 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
It's not safe to use an immediate heap object in generated unless we take
pains to ensure it's not in new space. Continue using the caller's context
for inlined functions on all platforms except IA32.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9427 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In some special (but probably very common) cases we can do better than loading
from a global cell for these global properties by emitting the corresponding
constant directly. This opens up opportunities for further improvements, coming
in a separate CL...
Review URL: http://codereview.chromium.org/7992002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9409 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
We have to check for uninitialized uses before phi-elimination. Otherwise we
may miss such a use and result in using the hole value instead. This
causes a NULL-dereference or assertion failure.
BUG=96989
TEST=mjsunit/compiler/regress-96989.js
Review URL: http://codereview.chromium.org/7974009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9337 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Although this patch is not small, most parts of it are rather mechanical:
* First of all, the concept of a 'nil-like' value is introduced, which can be
null or undefined. They are treated symmetrically regarding comparisons, so
it makes sense to handle them in a uniform manner. It is a mystery why
JavaScript defines two of those beasts, when even *one* is a design wart...
* Extended and renamed a few things which now handle undefined in addition to
null.
* Made the parts of the full code generator and the hydrogen generation which
deal with comparisons a bit more similar regarding their handling of special
cases.
* Refactored the syntactical detection of special cases for comparisons,
hopefully making them a bit more readable and less copy-n-paste-oriented.
Things like this should really be a one-liner in any sane programming
language... :-P
* Cut down the length of the argument lists of a few functions to something
less insane, making them more easily understandable locally. This involves
minor code duplication, but this was a good tradeoff and can be remedied
later if necessary.
* Replaced some boolean arguments with more readable enums.
* Fixed a TODO: Values which are definitely a Smi or unboxed can never be equal
to null or undefined.
Review URL: http://codereview.chromium.org/7918012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9323 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The Great Master Plan is to move the recognition of special cases for
comparisons further down the compilation pipeline where more information is
available. This is a first step into this direction: The special handling of
equality comparisons involving null is pushed from the parser to the code
generators, removing the need for a special AST node. (There are rumors from
usually well-informed sources that this node type is actually a relic of ancient
crankshaft days...)
The next steps will be the unification of null/undefined handling and pushing
the special case handling in crankshaft even further down the pipeline, enabling
the recognition of cases like "var foo=null; if (foo === bar) ...", but these
will be in separate CLs.
Review URL: http://codereview.chromium.org/7887037
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9293 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Removed an unneeded check for phis: There are never HValues in the work list
which are not convertible to integer and are not a phi. (But even if they were,
ignoring IsConvertibleToInteger() then looks like the wrong thing to do.)
Review URL: http://codereview.chromium.org/7857033
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9225 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Refactor Context::Lookup so it is more obvious. Change the comment in
contexts.h so it no longer indicates that it can return an arguments
object (it can't) and clean up the call sites that had leftover dead code.
BUG=
TEST=
Review URL: http://codereview.chromium.org/7782030
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9223 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When we propagate the information that a value is not convertible to integer,
there is no need for a separate fixed-point computation, we can do things the
"Millikin way" (tm), folding as much computation as possible into a single pass:
;-) We already have the phi node reachability information, so we can easily
propagate this while doing the representation histogram computation.
Review URL: http://codereview.chromium.org/7754010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9212 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The use-def relation between phis is mainly "forwards" (i.e. from phis with
smaller IDs to ones with larger IDs), so the fixed point computation terminates
faster when iterate through the phis in a "backwards" manner. This is quite
visible in complex Mandreel-generated code, where a few hundred phis with
non-trivial use-def chains are generated.
Review URL: http://codereview.chromium.org/7848012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9185 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The changes to scopes and parser introduce a VariableProxy
wrapping the function-name variable for function literals.
It seems the easiest way to get an AST id for the HSimulate
after context-slot stores in declarations.
Review URL: http://codereview.chromium.org/7826009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9112 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
We have to emit code for declarations later into the body block
(and not into the start block) so that the environment contains
the correct values.
In order to capture the environment effect of the declarations
that generate code (function declarations) I inserted a separate
AST id and a HSimulate after the declarations are visited.
Also fixes handling deopt in named function expressions:
BUG=v8:1647
TEST=test/mjsunit/regress/regress-fundecl.js, test/mjsunit/regress/regress-1647.js
Review URL: http://codereview.chromium.org/7776009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9083 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Changes GetGlobalReceiver() to GetDefaultReceiver(func) that returns undefined
for strict and native functions, and the function's context's global proxy
for "normal" functions.
BUG=v8:1547
TEST=cctest/api-test/ForeignFunctionReceiver
Review URL: http://codereview.chromium.org/7741042
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9030 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This eliminate redundant HChange instructions and allows range information of
converted values propagated across control-flow splits.
It fixes the performance regression on code like:
if (x > 1) {
y = x - 1;
}
where we should eliminate the overflow check on the sub inside the if-statement.
Review URL: http://codereview.chromium.org/7709025
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8997 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This improves our static type information by calculating the result type
of conversions (HChange) during range analysis. It allows e.g. to eliminate
the write barrier in the following example where it was not possible before:
function f(x) {
var y = x + 1;
if (y > 0 && y < 100) {
a[0] = y;
}
}
* Fix bug in Range::Copy. The minus-zero flags has to be preserved by default.
Review URL: http://codereview.chromium.org/7634022
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8994 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Some AST nodes (Property, Call, etc.) store either a list of receiver
types or a monomorphic receiver type. This patch merges the two fields
using a small pointer list. GetMonomorphicReceiverType() is now a
purely convenience function returning the first and only recorded
type.
This saves about 500K (of about 39M) on average when compiling V8
benchmark as measured by a simple patch adding a zone allocation
counter (https://gist.github.com/1149397).
R=kmillikin@chromium.org
Review URL: http://codereview.chromium.org/7655017
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8993 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Remove the try/finally used for with and catch. Instead of using
try/finally to handle break and continue from with or catch,
statically track nesting dept and clean up when compiling break or
continue.
And instead of using try/finally to handle throw to handler in a frame
whose pc is inside a with or catch, store the context that the handler
should run in in the handler itself.
BUG=
TEST=
Review URL: http://codereview.chromium.org/7618007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8922 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
