If a function contains more than a certain number of locals (IA32: 9, X64: 6, ARM: 4)
a loop for initializing the locals with 'undefined' is more compact.
For less locals we unroll that loop by emitting a sequence of push instructions.
Review URL: http://codereview.chromium.org/515012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3521 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This only wins us around 1% in performance, but it makes the code more
compact. We don't currently have a way to represent in the virtual
frame that a slot contains a value from the root array. Adding this
would probably make the code more compact.
Review URL: http://codereview.chromium.org/174639
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
deferred code snippets are highly stylized. They always make a call
to a stub or the runtime and then return. This change takes advantage
of that.
Creating a deferred code object now captures a snapshot of the
registers in the virtual frame. The registers are automatically saved
on entry to the deferred code and restored on exit.
The clients of deferred code must ensure that there is no change to
the registers in the virtual frame (eg, by allocating which can cause
spilling) or to the stack pointer. That is currently the case.
As a separate change, I will add either code to verify this constraint
or else code to forbid any frame effect.
The deferred code itself does not use the virtual frame or register
allocator (or even the code generator). It is raw macro assembler
code.
Review URL: http://codereview.chromium.org/118226
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2112 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2038 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
