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
Introducing a virtual-frame-inl.h file containing some platform-independent
virtual frame function which are small enough to be inlined.
Removed unnecessary #include of virtual-frame.h from register-allocator-inl.h
and added the necessary explicit includes in a number of files.
Review URL: http://codereview.chromium.org/660104
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3962 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Each frame element gets a new attribute with number type information. A frame element can be:
- smi
- heap number
- number (i.e. either of the above)
- or something else.
The type information is propagated along with all virtual frame operations.
Results popped from the frame carry the number information with them.
Two optimizations in the code generator make use of the new
information:
- GenericBinaryOpSyub omits map checks if input operands are numbers.
- Boolean conversion for numbers: Emit inline code for converting a number (smi or heap number) to boolean. Do not emit call to ToBoolean stub in this case.
Review URL: http://codereview.chromium.org/545007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3861 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
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
fast code generator is optimized for compilation time and code size.
Currently it is only implemented on IA32. It is potentially triggered
for any code in the global scope (including code eval'd in the global
scope). It performs a syntactic check and chooses to compile in fast
mode if the AST contains only supported constructs and matches some
other constraints.
Initially supported constructs are
* ExpressionStatement,
* ReturnStatement,
* VariableProxy (variable references) to parameters and
stack-allocated locals,
* Assignment with lhs a parameter or stack-allocated local, and
* Literal
This allows compilation of literals at the top level and not much
else.
All intermediate values are allocated to temporaries and the stack is
used for all temporaries. The extra memory traffic is a known issue.
The code generated for 'true' is:
0 push ebp
1 mov ebp,esp
3 push esi
4 push edi
5 push 0xf5cca135 ;; object: 0xf5cca135 <undefined>
10 cmp esp,[0x8277efc]
16 jnc 27 (0xf5cbbb1b)
22 call 0xf5cac960 ;; code: STUB, StackCheck, minor: 0
27 push 0xf5cca161 ;; object: 0xf5cca161 <true>
32 mov eax,[esp]
35 mov [ebp+0xf4],eax
38 pop eax
39 mov eax,[ebp+0xf4]
42 mov esp,ebp ;; js return
44 pop ebp
45 ret 0x4
48 mov eax,0xf5cca135 ;; object: 0xf5cca135 <undefined>
53 mov esp,ebp ;; js return
55 pop ebp
56 ret 0x4
Review URL: http://codereview.chromium.org/273050
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3067 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The profile is taken together with constructors profile. In theory, it
should represent a complete heap graph. However, this takes a lot of memory,
so it is reduced to a more compact, but still useful form. Namely:
- objects are aggregated by their constructors, except for Array and Object
instances, that are too hetereogeneous;
- for Arrays and Objects, initially every instance is concerned, but then
they are grouped together based on their retainer graph paths similarity (e.g.
if two objects has the same retainer, they are considered equal);
Review URL: http://codereview.chromium.org/200132
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2903 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
-fstrict-aliasing is enabled by mainline gcc at -O2 and higher, but in Apple
gcc, it must be enabled explicitly. This results in a 1.5% improvement in V8
benchmark scores.
This also removes the -fno-exceptions and -fno-rtti settings from v8.gyp for
the Mac, and removes -fno-rtti from v8.gyp for Linux, because these settings
have become part of Chromium's common.gypi, included here, as of r23304 at the
latest. The settings in v8.gyp have become redundant.
Review URL: http://codereview.chromium.org/174154
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2734 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
system can't currently process stacks produced by gcc -fomit-frame-pointer
properly. The drawback outweighs the 2% performance improvement. Once
the crash reporting system is able to handle this optimization, it should be
revisited.
Review URL: http://codereview.chromium.org/173123
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2733 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
generated in one-pass from the source AST, code is generated from the
CFG. Enabled by the flag --multipass and disabled by default.
Rudimentary and currently only supports literal expressions and return
statements. There are some other known limitations (e.g., missing
support for tracing).
Review URL: http://codereview.chromium.org/159695
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2596 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
