of having a list of virtual frame pointers in the jump
target we have one virtual frame, which is the frame that
all have to merge to to branch to that frame.  The virtual
frame in the JumpTarget is inside the JumpTarget, rather than
being an allocated object that is pointed to.  Unfortunately
this means that the JumpTarget class has to be able to see
the size of a VirtualFrame object to compile, which in turn
lead to a major reorganization of related .h files.  The
actual change of functionality in this change is intended
to be minimal (we now assert that the virtual frames match
when using JumpTarget instead of just assuming that they do).
Review URL: http://codereview.chromium.org/1961004

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The stack check has been moved from the Accept function dispatching on
the AST node type, earlier to the Visit function dispatching on the
visitor type.

This allows very simple non-recursive visitors (not taking extra
arguments or returning values) via the convention of calling "Visit"
if one wants the stack check and "Accept" if one does not.  Recursive
calls should all be via "Visit".

Review URL: http://codereview.chromium.org/1567007

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Cut down on the number of arguments passed to the various binary operation
code generator functions by passing along the expression itself, rather than
a subset of its fields.

Review URL: http://codereview.chromium.org/1592001

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The flow graph has been simplified to remove the special branch, join,
and exit nodes.  All nodes are now basic blocks (possibly empty to
preserve edge-split form) with a distinguished entry and exit block.

Most trivial expressions are not added to the flow graph as
instructions.  The assigned variable analyzer has been changed to
sometimes work right-to-left so that right subexpressions can be
marked as trivial.

The reaching definitions analysis has been temporarily removed, and
the analyses that depended on it (primitivity analysis, dead code
marking) as well.

Review URL: http://codereview.chromium.org/1530003

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Review URL: http://codereview.chromium.org/1233003

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As part of aggressive dead code elimination, we initially assume all
flow-graph instructions are not live.  We mark those that are critical
and recursively all their children.  The children of variable
references (VariableProxies occurring as rvalues) include all their
reaching definitions.

Review URL: http://codereview.chromium.org/1159005

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Previously we marked compare operations that occurred as for loop
conditions so as to avoid inlining the floating-point code for them.
Begin marking all expressions that occur as any loop condition
(because they are never dead code).

Review URL: http://codereview.chromium.org/1074009

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This change adds a data-flow pass to statically determine
if a variable contains a primitive type.

It requires building the flow graph and computing reaching
definitions as pre-requisites. The analysis annotates all
VariableProxy nodes with the result.

Review URL: http://codereview.chromium.org/1132005

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  their place.
- Add one field to the SharedFunctionInfo to remember the number of
  literals used in this function.

Review URL: http://codereview.chromium.org/669240

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This change adds the option to peel off the first iteration of inner loops.

Loop peeling is off by default and can enabled by a flag. It also requires building a flow graph.

As part of this I added the possibility to clone AST nodes.

Review URL: http://codereview.chromium.org/998001

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After computing RD_in for all flow graph nodes, push the reaching
definitions through the basic blocks to annotate all variable
references in the AST.

Review URL: http://codereview.chromium.org/889003

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IsPrimitive reflects that an expression's value is known statically to
be one of the ECMA-262-3 JS types other than Object (e.g., Undefined,
Null, Boolean, String, or Number).

The type conversions ToPrimitive, ToNumber, ToInteger, ToInt32,
ToUInt32, ToUint16, ToString, or ToObject cannot invoke user code for
primitive input values.  ToObject throws a TypeError if its input is
Undefined or Null.

Review URL: http://codereview.chromium.org/912002

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This change fixes a bug with the arguments object that occurred with
r4087 and r4088. The fix is not marking the arguments variable as trivial
since it can have side effects.


Review URL: http://codereview.chromium.org/851002

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Review URL: http://codereview.chromium.org/805005

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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

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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

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Review URL: http://codereview.chromium.org/549207

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Review URL: http://codereview.chromium.org/507051


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location to an Expression AST node from the node's parent to the node
itself.

This allows an inherited code generation context from a parent node to
be passed arbitrarily far down the tree (eg, the subexpression of a
unary not is in the same context as the unary expression itself, the
then and else subexpressions of the ternary operator are in the same
context as the whole expression, and so forth).

We do not yet take advantage of this in the backend (eg, the right
subexpression of short-circuited OR is still compiled by using the
parent's destination location, rather than the subexpression's
itself).

Review URL: http://codereview.chromium.org/340005

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implementation is not yet complete (it prints only the node name for
some AST constructs) and does not serialize everything needed to
reconstitute the AST.

It is motivated by a desire to prototype source-to-source
transformations in JavaScript itself (or anything else that can grok
JSON), but it should have other uses too.

Feedback is welcome.
Review URL: http://codereview.chromium.org/131101

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while, and for loops.

Previously they were distinguished by a type field, which required
runtime asserts to avoid invalid nodes (since not all loop types have
the same internal structure).  Now they C++ type system is used to
require well-formed loop ASTs.

Because they do not share compilation code, we had very large
functions in the code generators that merely did a runtime dispatch to
a specific implementation based on the type.
Review URL: http://codereview.chromium.org/269049

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differentiating between Call and CallEval except in the code
generator, and the difference can be detected from a regular Call AST
node at code generation time.

Review URL: http://codereview.chromium.org/245042

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Review URL: http://codereview.chromium.org/159633

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This allows Function.prototype.apply to not allocate the objects 
and copy the arguments directly from the stack.
Review URL: http://codereview.chromium.org/147075

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This issue was raised by Brett Wilson while reviewing my changelist for readability. Craig Silverstein (one of C++ SG maintainers) confirmed that we should declare one namespace per line. Our way of namespaces closing seems not violating style guides (there is no clear agreement on it), so I left it intact.

Review URL: http://codereview.chromium.org/115756


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  the properties as well.  This fixes some failing tests.
- Moved json parsing into native code.


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Review URL: http://codereview.chromium.org/48006

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Review URL: http://codereview.chromium.org/46088

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blocks labeled by "break", "continue", and "return".  BreakTargets are
the only jump targets that appear in the AST, the only ones that can
be uninitialized, and the only ones that can be shadowed.
Review URL: http://codereview.chromium.org/42008

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Review URL: http://codereview.chromium.org/40295

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Optimizing nested, constant object literals (like JSON objects) by building one large object template for the entire object instead of one for each sub-object.
Review URL: http://codereview.chromium.org/39184

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Choice nodes may know that they are never not at the start of input.
This can remove start_of_input assertions in cases where they are statically known to fail.
The initial loop is unrolled once if the regexp might check for the start of input. Only the first iteration may be at the start, the following loop knows that it isn't.


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also revealed a bug or two that had to be fixed.


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Review URL: http://codereview.chromium.org/12673

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Review URL: http://codereview.chromium.org/12427

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