This change adds a pass over the AST that computes the
set of assigned variables for locals and parameters for each expression.

The result of this analysis is used to for two purposes:
1. Recognize variables that are trivial subexpressions. A left sub-expression
   of a binary operation is trivial if it is a local variable or a parameter
   and it is not assigned in the right sub-expression. In the case of a 
   trivial left sub-expression we evaluate the right first.
   Currently only binary operations and compare operations are considered
   when finding trivial left sub-expressions.

2. Recogize certain simple for-loops with a constant trip count where the loop
   variable is always within smi range. If the loop count variable is not
   assigned in the body of the loop (except in the update expression the
   for-loop). This allows omitting smi checks on operation using the loop
   count variable.

Review URL: http://codereview.chromium.org/669155

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4087 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Visitor stack overflow is used to signal an unsupported construct in
the flow graph.  Check for it in more places.  Make the utility
functions for appending to graphs handle more cases if they can be
handled correctly.

Remove the entry node in favor of a block with a NULL predecessor as
single entry.  Represent the empty flow graph as a single empty block.
Add empty blocks lazily where needed to preserve edge-split form.

Review URL: http://codereview.chromium.org/804003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4086 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=fschneider@chromium.org

Review URL: http://codereview.chromium.org/802003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4085 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

While the flow graph is experimental, it's easier to be able to ignore
some problematic syntactic constructs.  Reduce the ones that can occur
in constructed flow graphs.

Review URL: http://codereview.chromium.org/790004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4084 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

probably want to remove this again if and when Dromaeo is
fixed so this strategy doesn't pay off.
Review URL: http://codereview.chromium.org/817001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4083 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/821001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4082 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/778005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4081 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=erik.corry@gmail.com
Review URL: http://codereview.chromium.org/802002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4078 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

It causes regressions on test shell tests.

TBR=antonm@chromium.org
Review URL: http://codereview.chromium.org/819001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4075 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

r4071 made BitVector zone-allocated, but the BitVector tests were not
changed to allocate a Zone.

Review URL: http://codereview.chromium.org/818001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4072 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Change the BitVector utility class to allow allocation via 'new' in the
Zone.  Change the backing store to be always zone-allocated.

Review URL: http://codereview.chromium.org/730001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4071 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/747002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4070 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/668246

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4069 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Now this builtin checks if it should go into fast case or resort to JS ArrayPush builtin.

Review URL: http://codereview.chromium.org/660298

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4068 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

stats to make sure PRIVATE_EXTERNAL_ASCII_STRING_TYPE fits.
Review URL: http://codereview.chromium.org/726002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4067 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

A separate object type for the code cache have been added. This object has two different code caches. The first one (default_cache) is a fixed array organized in the same way as the as the code cache was before. The second cache (global_access_cache) is for code stubs to access the global object. This cache is organized as a hash table taking the property name and code flags as the key.

The reason for separating the global access stubs into a hash table representation is that the number of these is not bounded in the same was as the other types.

This is a remake of r3952 (http://codereview.chromium.org/652119) which have the additional ability to look for the index of code stubs for access to the global object.

BUG=http://code.google.com/p/v8/issues/detail?id=613

Review URL: http://codereview.chromium.org/717001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4066 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Add a simple boolean helper function for Variables and Slots.

Review URL: http://codereview.chromium.org/722001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4065 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Before computing reaching definitions, the set of all definitions in a
function must be collected and they must be numbered.  Have the flow
graph builder collect definitions for stack-allocated variables into a
list, and implicitly number them with their list index.

Review URL: http://codereview.chromium.org/668257

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4064 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/668259

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4063 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

interactions between idle notifications for background tabs
and the context disposal GCs even further.
Review URL: http://codereview.chromium.org/698003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4062 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The fast case of looking up the string convertion of the smi did not handle the case where left/reghe operands could be in eax/edx instead of edx/eax which is the default.

Also got rid of creating an internal frame for calling string and instead patched the argument on the stack and performed a tail call.

BUG=http://code.google.com/p/v8/issues/detail?id=636
TEST=test/mjsunit/regress/regress-636.js
Review URL: http://codereview.chromium.org/720001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4061 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Added zone-inl.h to jsregexp.h since it relies on calling new ZoneList which again relies on calling the static new method on Zone (defined in zone-inl.h but declared in zone.h).
Review URL: http://codereview.chromium.org/719001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4060 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Added zone-inl.h to test-heap-profiler to fix test build failure after header file refactoring in revision 4058. 
Review URL: http://codereview.chromium.org/698002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4059 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Remove messages.h from v8.h and include it explicitly in only the few places
it is needed.  Many files relied on getting handles-inl.h implicitly from
messages.h through v8.h, so include handles-inl.h explicitly in v8.h
instead.

Remove zone-inl.h from header files where it is not needed, can be replaced
by a forward declaration, or can be replaced by zone.h (specifically,
factory.h and heap.h).  Include zone.h or zone-inl.h in header files where
it was implicitly included via heap.h or factory.h.  Prefer zone.h over
zone-inl.h in header files where possible by including zone-inl.h in .cc
files.

Review URL: http://codereview.chromium.org/668248

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4058 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/668258

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4057 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Simplify AST analysis of side-effect-free int32 expressions.
Review URL: http://codereview.chromium.org/668256

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4056 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/669272

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4055 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Also changed name of GeneratePow and the %_ call name to follow convention based on MathSin and MathCos. Moved GeneratePow down to the other methods. 

Review URL: http://codereview.chromium.org/661179

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4054 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=fschneider@chromium.org

Review URL: http://codereview.chromium.org/669271

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4053 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

A variable usage analysis pass was run on toplevel and lazily-compiled
code but never used.  Remove this pass and the data structures it
builds.

The representation of variable usage for Variables has been changed
from a struct containing a (weighted) count of reads and writes to a
simple flag.  VariableProxies are always used, as before.  The unused
"object uses" is removed.

Review URL: http://codereview.chromium.org/669270

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4052 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The flow graph is built by walking the AST.  Edges are labeled with
instructions (AST nodes).  Normal nodes have a single predecessor edge and a
single (labeled) successor edge.  Branch nodes are explicit, they have a
single predecessor edge and a pair of (unlabeled) successor edges.  Merge
nodes are explicit, they have a pair of predecessor edges and a single
(unlabeled) successor edge.

There is a distinguished (normal) entry node and a distinguished (special)
exit node with arbitrarily many predecessor edges and no successor edges.

The graph is intended to support graph-based analysis and transformation.

Review URL: http://codereview.chromium.org/660449

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4051 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/661469

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4050 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

how many pending context disposals there are.
Review URL: http://codereview.chromium.org/669266

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4049 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/669161

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4048 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/668203

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4047 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Makes NumberInfo into a real class.
Fix bug where NumberInfo was lost in ToRegister.
Allow 17 bits in safe Smis instead of 16.
Review URL: http://codereview.chromium.org/668151

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4046 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/652027

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4045 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: http://codereview.chromium.org/669164

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4044 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=sgjesse@chromium.org

Review URL: http://codereview.chromium.org/668160

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4043 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=sgjesse@chromium.org

Review URL: http://codereview.chromium.org/669162

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4042 ce2b1a6d-e550-0410-aec6-3dcde31c8c00