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
Reaching definitions in (RD_in) is initially empty for all nodes. Gen
and kill sets are computed. AST node numbers are used for nodes to
refer to their definition number.
Also: two small changes to flow graph printing. Children of branch
nodes are visited in right-to-left order when performing depth first
search. Instructions are numbered locally within blocks so as to not
destroy AST node number before printing (it's useful to print the
definition).
Review URL: http://codereview.chromium.org/876001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4107 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
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
Add a (currently) syntactic predicate to AST expression nodes telling
whether they are 'trivial'. Trivial expressions have no side effects,
do not require storage to be allocated for them, and can be evaluated
out of order (because their value does not change between when they
are visited by the code generator as expressions in the AST and when
it is consumed).
Mark 'this' and literals as trivial. Allow them to be pushed on the
virtual frame. Make use of them to push 'this' more lazily in this
property assignments.
Review URL: http://codereview.chromium.org/647018
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3906 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change add simple local live variable information to
the fast code generator. It supports only AST nodes that
are accepted by the syntax checker.
Each variable use points to a variable definition structure
which contains the last use of the definition.
To determine whether a variable is live after a certain point
we can check whether its last use occurs later in the evaluation
order defined by the AST labeling number.
The new information is currently only printed out together with
the IR and not yet used for code generation.
Review URL: http://codereview.chromium.org/603004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3839 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Support a binary operation (bitwise OR) so long as it's not nested in
the left subexpression. This ensures that the expression stack never
has height greater than two and so can be kept fully in registers.
The bounded expression stack height and the absence of any side
effects on the fast path allows us to still bailout out to the very
beginning of the function if any of our fast-path checks fail.
Review URL: http://codereview.chromium.org/594008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3822 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change adds a post-order numbering to AST nodes that
are relevant for the fast code generator. It is only invoked
together with the fast compiler.
Also changed the ast printer to print the numbering for
testing purposes if it is present.
Review URL: http://codereview.chromium.org/553134
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3738 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
generator.
Contexts are no longer stored in the AST but in the code generator's
state. This means that the running the code generator selector is not
required to use the toplevel code generator (for instance, if we
already know that we can and should use it).
Review URL: http://codereview.chromium.org/546075
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3645 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Replace runtime call to NumberAdd with call to binary op stub.
Until now the top-level compiler always called a runtime function
for count operations.
In some places we expected in the JS builtins smis as arguments.
If we perform a count operation before all smis would get converted into
heap numbers by the runtime number add function and result in a runtime
assert.
Also: Add missing debugger information in the top-level compiler for
do-while loops.
Review URL: http://codereview.chromium.org/548029
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3610 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
* Rename the operation of filling a context with a value. Formerly it
was 'Move', now it's 'Apply' so as to avoid confusion with various
other Moves (eg, in the toplevel codegen, in the macro assemblers).
* Use the abstraction Drop rather than math on the stack pointer.
* Add a predicate on AST expression nodes to abstract a repeated test
whether we should us a regular (named) IC or a keyed IC.
Review URL: http://codereview.chromium.org/546006
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3580 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Condition block of do/while statements is a valid break location so it should have its own position. The block is represented by a regular Expression node so we cannot store the position in it, instead the position is stored in a separate field in DoWhileStatement AST node.
BUG=514
Review URL: http://codereview.chromium.org/385136
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3312 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
directly-applied function literals that are themselves compiled with
the top-level code generator.
The choice is guarded by a test that the function is anonymous (thus
not expected to be recursive) and not in a loop.
A compilation hint is set in the shared function info and used to make
the choice.
Review URL: http://codereview.chromium.org/341081
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3206 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
context. Test contexts are used for the left subexpressions of
short-circuited boolean operators. The right subexpressions inherit
their expression context from the binary op expression.
Compilation of short-circuited operations in effect and test context
is straightforward:
effect(e0 || e1) =
test(e0, L0, L1)
L1: effect(e1)
L0:
test(e0 || e1, L0, L1) =
test(e0, L0, L2)
L2: test(e1, L0, L1)
Because the value of the first subexpression may be needed as the
value of the whole expression in a value context, we introduce a
hybrid value/test contest (the value is needed if true, but not if
false).
value(e0 || e1) =
value/test(e0, L0, L1)
L1: value(e1)
L0:
The compilation of value/test and test/value (introduced by boolean
AND) is:
value/test(e0 || e1, L0, L1) =
value/test(e0, L0, L2)
L2: value/test(e1, L0, L1)
test/value(e0 || e1, L0, L1) =
test(e0, L0, L2)
L2: test/value(e1, L0, L1)
Boolean AND is the dual. The AST nodes themselves (not their parents)
are responsible for producing the proper result (effect, value, or
control flow) depending on their context.
Review URL: http://codereview.chromium.org/339082
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3187 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
context of the expressions they label. Introduce an "unintialized"
location to catch failure to assign any location at all.
Changed the object literal initialization on ARM to use a Store IC in
the same cases where it did on the other platforms. This was required
because the location of the literal property name is given an
"unitialized" location.
Review URL: http://codereview.chromium.org/339045
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3171 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
fast-mode code generator.
AST expression nodes are annotated with a location when doing the
initial syntactic check of the AST. In the current implementation,
expression locations are 'temporary' (ie, allocated to the stack) or
'nowhere' (ie, the expression's value is not needed though it must be
evaluated for side effects).
For the assignment '.result = true' on IA32, we had before (with the
true value already on top of the stack):
32 mov eax,[esp]
35 mov [ebp+0xf4],eax
38 pop eax
Now:
32 pop [ebp+0xf4]
======== On x64, before:
37 movq rax,[rsp]
41 movq [rbp-0x18],rax
45 pop rax
Now:
37 pop [rbp-0x18]
======== On ARM, before (with the true value in register ip):
36 str ip, [sp, #-4]!
40 ldr ip, [sp, #+0]
44 str ip, [fp, #-12]
48 add sp, sp, #4
Now:
36 str ip, [fp, #-12]
Review URL: http://codereview.chromium.org/267118
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3076 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
"jsregexp.h" and "jump-target.h" required "macro-assembler.h" to
always be included first. Instead the include of "macro-assembler.h"
has moved into those header files.
"dateparser-inl.h" required "dateparser.h" to always be included
first. Instead the include of "dateparser.h" has moved into
"dateparser-inl.h".
Review URL: http://codereview.chromium.org/267117
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3074 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
1. Change the AST node type CallNew to be a subclass of Expression
rather than Call. It's not really a call but it just happens to
have the same fields.
2. Change our error reporting for invalid left-hand sides in for-in
statements, pre- and postfix count expressions, and assignments.
Before we signaled a syntax error at compile time *unless* the LHS
was a function call or 'new' expression, in which case we signaled
a reference error at runtime. Now we signal a reference error at
runtime in all cases. This matches the JSC behavior in Safari 4.
Review URL: http://codereview.chromium.org/249039
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2994 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
During parsing functions are analyzed for statements of the form this.x = ...;. These assignments are categorized in two types: simple and non simple. The simple ones are where the right hand side is known to be either a constant or an argument to the function. If a function only contains statements of this type the property names are collected and for the simple assignments the index of the argument or the constant value assigned are stored as well.
When the initial map for a function is created and the function consists of only this type of assignemnts the initial map is created with a descriptor array describing these properties which will be known to always exist in an object created from the function.
The information on this property assignments is not collected during pre-parsing so if compiling using pre-parse data these optimization hints are not available.
Next step will be to use the information collected for the simple assignments to generate constructor code which will create and initialize the object from this information without calling the code for the function.
Review URL: http://codereview.chromium.org/172088
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2710 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
