To avoid deopts a few extra changes were needed:
o Enable megamorphic state for special property loads on
primitives. We used to flip between monomorphic stubs.
o Extract pure string (no string wrapper support) version of the
string length stub.
Review URL: http://codereview.chromium.org/6334015
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6472 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Code generated for checks starting with primitive receivers skips one step
in the usual prototype checking algorithm, so the holder must always be set.
Not setting the holder did not cause an immediate failure because our
primitives have additional hidden prototypes before the real prototypes.
These extra objects in the chain usually contain no properties and so
allowed the right holders to be selected.
Review URL: http://codereview.chromium.org/6353014
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6459 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This patch adds H- and L-variants of StringCharCodeAt and StringLength.
StringCharCodeAt is used to inline a constant function call of
String.prototype.charCodeAt and to implement the corresponding inline
runtime function. It does not yet use the recently introduced extra IC
state. (We can specialize on string encoding and avoid deopts because
of out of bounds accesses.)
StringLength needs more work because the stub version of it also
supports strings wrappers and it matters in some cases. (We have to
separate the string only case.)
Review URL: http://codereview.chromium.org/6243008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6408 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix CalculateEmitStore HashMap use.
The hash maps are setup to store strings or smis but instead Literal is being in them. It seems to only work by accident.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6279 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This fixes V8 issue 989.
Before, assignments used the AST ID of the assignment expression to
mark the side effect of the store, which became a target for
deoptimization bailout for code after the assignment. In effect
contexts this environment included the value of the assignment, which
was unexpected by the unoptimized code.
Now we introduce a new assignment ID for AST node types that include
an assignment (Assignment, CountOperation, and ForInStatement) and use
it for the side effect of the store.
Review URL: http://codereview.chromium.org/5682010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5990 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
For some reason, the scope's arguments and arguments shadow were
variable proxies, which resulted in all references to the arguments
shadow being shared in the AST. This makes it hard to put per-node
state on the AST nodes.
I took the opportunity to remove Variable::AsVariable which has
confused people in the past, and to rename Variable::slot to the more
accurate Variable::AsSlot.
Review URL: http://codereview.chromium.org/3432022
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@5517 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4631 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4320 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4307 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4246 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4227 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4224 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4205 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4116 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
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
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3163 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3051 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3048 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
