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
o.x() and o[expr]()
other changes:
- Fix missing relocation info for StoreIC on global object.
- Generate only one common return sequence instead of always appending
"return <undefined>" at the end of each function: The first JS
return-statement will generate the common return sequence. All
other return-statements will generate a unconditional branch to the common
return sequence.
Review URL: http://codereview.chromium.org/340037
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3183 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The code for .result = (b.y = 99) where b is a global variable is:
push [esi+0x17]
mov ecx,0xf5c229ad ;; object: 0xf5c229ad <String[1]: b>
call LoadIC_Initialize
nop
mov [esp],eax
mov eax,0xc6
mov ecx,0xf5c25c41 ;; object: 0xf5c25c41 <String[1]: y>
call StoreIC_Initialize
nop
mov [esp],eax
pop [ebp+0xf4]
There is still some room for improvement in the generated code.
Other changes:
- Replaced switch-statement in FastCodeGenerator::VisitProperty with DropAndMove(...)
- Do not emit nop after IC calls on ARM.
Review URL: http://codereview.chromium.org/347001
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3180 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
- don't engage the processing thread of CPU profiling until the first time profiling is resumed, this saves us a thread allocation for the majority of users;
- don't log shared libraries addresses: this is useless for JS-only profiling, and also consumes time on startup.
Review URL: http://codereview.chromium.org/340013
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3154 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
String slices from RegExp replace results is now encoded in either one or two smis. Substrings are not used any more.
If the existing one smi encoding cannot hold the start/length information two smis are used the first having the negative length and the second having the start.
This is in preparation for removing string slices.
Review URL: http://codereview.chromium.org/342015
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3153 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Literals now have a location of temporary by default and are
responsible for moving themselves into their location like all other
expressions.
The constant location turned out not to allow us to avoid checking
subexpressions in AST interior nodes, and it turned out to require
checking after some normal calls to Visit (like for the arguments to a
call). With this change do not have to check after a call to Visit
that we got our result in the expected location.
Review URL: http://codereview.chromium.org/339004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3137 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
