When an array index (in an array access) is a simple "expression + constant", just embed the constant in the array access operation so that the full index expression is (potentially) no longer used and its live range can be much shorter.
This is effective in conjunction with array bounds check removal (otherwise the index is anyway used in the check).
Review URL: https://chromiumcodereview.appspot.com/10382055
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11596 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
As a special case, for checks on index expressions with the form (expr + constant) if a smaller constant is checked later in the DT also eliminate the check.
Finally, if a larger constant is checked later in the same BB do the more general check (larger constant) earlier instead of the less general one.
This will not cause useless deoptimizations because, since we are in the same BB, all the checks would have been executed anyway.
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/10032029
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11437 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Do proper dispatch on declaration type instead of mingling together
different code generation paths. Once we add more declaration forms,
this is more scalable.
In separate steps, I'd like to (1) clean up the logic for DeclareGlobal,
and (2) try to reduce the special handling of the name function var if
possible.
R=fschneider@chromium.org
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/9704054
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11331 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change allows hydrogen instructions to keep track of instructions
that dominate certain side-effects (GVN flags) in the hydrogen graph. We
use the GVN pass to keep track of side-effects because accurate flags
are already in place.
It also adds a new side-effect (kChangesNewSpacePromotion) indicating
whether an instruction can cause a GC and have objects be promoted to
old-space. An object allocated in new-space is sure to stay on paths not
having said side-effect.
R=erik.corry@gmail.com
TEST=mjsunit/compiler/inline-construct
Review URL: https://chromiumcodereview.appspot.com/10031031
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11270 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Modify PreProcessOsrEntry to work with OSR entries that have non-empty expression stack.
Modify graph builder to take for-in state from environment instead of directly referencing emitted instructions.
Extend %OptimizeFunctionOnNextCall with an argument to force OSR to make writing OSR tests easier: %OptimizeFunctionOnNextCall(f, "osr").
R=fschneider@chromium.org
TEST=test/mjsunit/compiler/optimized-for-in.js
Review URL: https://chromiumcodereview.appspot.com/9431030
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10796 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Only JSObject enumerables with enum cache (fast case properties, no interceptors, no enumerable properties on the prototype) are supported.
HLoadKeyedGeneric with keys produced by for-in enumeration are recognized and rewritten into direct property load by index. For this enum-cache was extended to store property indices in a separate array (see handles.cc).
New hydrogen instructions:
- HForInPrepareMap: checks for-in fast case preconditions and returns map that contains enum-cache;
- HForInCacheArray: extracts enum-cache array from the map;
- HCheckMapValue: map check with HValue map instead of immediate;
- HLoadFieldByIndex: load fast property by it's index, positive indexes denote in-object properties, negative - out of object properties;
Changed hydrogen instructions:
- HLoadKeyedFastElement: added hole check suppression for loads from internal FixedArrays that are knows to have no holes inside.
R=fschneider@chromium.org
BUG=
TEST=
Review URL: https://chromiumcodereview.appspot.com/9425045
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10794 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change enables optimization of top-level and eval-code. For this to work, it adds
support for declaring global variables in optimized code.
At the same time it disables the eager generation of deoptimization support data
in the full code generator (originally introduced in
r10040). This speeds up initial compilation and saves
memory for functions that won't be optimized. It requires
recompiling the function with deoptimization
support when we decide to optimize it.
Review URL: https://chromiumcodereview.appspot.com/9187005
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10700 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Until now we only could inline as specialized HIR instructions when called
as a method (e.g. Math.abs)
It is very common practice to abbreviate calls to those functions by defining
a global or local variable like:
var a = Math.abs;
var x = a(123);
This change allows inlining them when called as a function (global or local).
Review URL: https://chromiumcodereview.appspot.com/9365013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10640 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This CL introduces a third mode next to the non-strict
(henceforth called 'classic mode') and 'strict mode'
which is called 'extended mode' as in the current
ES.next specification drafts. The extended mode is based on
the 'strict mode' and adds new functionality to it. This
means that most of the semantics of these two modes
coincide.
The 'extended mode' is entered instead of the 'strict mode'
during parsing when using the 'strict mode' directive
"use strict" and when the the harmony-scoping flag is
active. This should be changed once it is fully specified how the 'extended mode' is entered.
This change introduces a new 3 valued enum LanguageMode
(see globals.h) corresponding to the modes which is mostly
used by the frontend code. This includes the following
components:
* (Pre)Parser
* Compiler
* SharedFunctionInfo, Scope and ScopeInfo
* runtime functions: StoreContextSlot,
ResolvePossiblyDirectEval, InitializeVarGlobal,
DeclareGlobals
The old enum StrictModeFlag is still used in the backend
when the distinction between the 'strict mode' and the 'extended mode' does not matter. This includes:
* SetProperty runtime function, Delete builtin
* StoreIC and KeyedStoreIC
* StubCache
Review URL: http://codereview.chromium.org/8417035
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10062 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change fixes a off-by-one level error when dropping the
function from the environment. The function of the outermost
environment was not dropped.
BUG=v8:1785
TEST=test/mjsunit/compiler/regress-inline-callfunctionstub.js
Review URL: http://codereview.chromium.org/8341019
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9789 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change is based on my previous change enabling inlining calls-as-function
fixing the bugs related to deoptimization.
The function value on top of the environment was dropped too late in the old code.
As a result we could get a wrong value on top after deoptimization.
This change includes r9619. It was reverted because of test failures that are fixed
with this patch.
Review URL: http://codereview.chromium.org/8360001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9758 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This time, we initially leave the HTypeof instruction in the Hydrogen graph,
even for the special cases. We later try to remove this instruction (and any
HConstant) in the canonicalization pass, if possible. Always removing the
HTypeof during the initial graph construction is wrong if e.g. it is used in an
HSimulate.
The removals can be generalized a bit, but this will happen in a separate CL.
TEST=mjsunit/optimized-typeof.js
Review URL: http://codereview.chromium.org/8334021
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9688 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Previously, comparisons against null/undefined and comparisons of the result of
typeof against a constant string were done syntactically. Now we do this via
pattern matching on the hydrogen graph, which opens up more opportunities for
better code generation, e.g. the following comparisons are now recognized to be
special:
var bar = typeof foo;
var baz = "undefined";
if (bar == baz) ...
var blah = undefined;
if (hurz == blah) ...
If we did this handling of special cases even later at lithium generation time,
even more cases could be recognized, but this would involve bigger changes and
this CL handles most common cases.
Review URL: http://codereview.chromium.org/8242002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9612 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This eliminates compile-errors when assigning Handle<SerializedScopeInfo> to
Handle<Object> in a place where the declaration was not available because
variables.h was not included.
As a result I had to also move the enum Variable::Mode to v8globals.h and
rename it to VariableMode.
Review URL: http://codereview.chromium.org/8221004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9575 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
