Bit tests with a memory operand should be avoided on Intel processors.
On Atom bts with a memory operand has 10~11 cycles latency and on Core 2
it has 5~6 cycles latency, and also produces multiple uops.
If the bit base operand is a register the latency is 1 cycle instead.
This CL improves several cases from Kraken 1.1 benchmark on Atom. For example,
12% for imaging-desaturate, 8% for audio-fft, and 5% for audio-beat-detection.
Review URL: http://codereview.chromium.org//7048003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7987 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When the stub return a heap number we do a state transition to
a version HEAP_NUMBER that can handle -0.
There is room for further improvement in the typefeedback for the
case of -0. This change however does not address this and only fixes
the acute issue.
Review URL: http://codereview.chromium.org/7037025
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7944 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Better support for 'polymorphic' JS and external arrays
Allow keyed store/load stubs to switch between external array and fast JS arrays without forcing a state transition to the generic stub.
There CL consists of two pieces of functionality. First, code stubs for fast element arrays don't immediately transition to the MEGAMORPHIC state when there's a map mismatch. Second, two ICs are cached per map for fast elements, the MONOMORPHIC version, and a new MEGAMORPHIC version that handles two or more different maps and dispatches to shared stubs to perform the array operation.
Review URL: http://codereview.chromium.org/7036016
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7935 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
As a side note, this change has some positive impact on the performace, e.g. imaging-darkroom is 8.3% faster and ws-ieee754conv is even 19.9% faster. No idea why the speedup is so big in some cases, but never look a gift horse in the mouth... ;-)
Review URL: http://codereview.chromium.org/7042004
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7926 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Allow keyed store/load stubs to switch between external array and fast JS arrays without forcing a state transition to the generic stub.
There CL consists of two pieces of functionality. First, code stubs for fast element arrays don't immediately transition to the MEGAMORPHIC state when there's a map mismatch. Second, two ICs are cached per map for fast elements, the MONOMORPHIC version, and a new MEGAMORPHIC version that handles two or more different maps. Currently, the only array types supported by the MEGAMORPHIC stub are fast elements for objects and JSArrays.
BUG=
TEST=
Review URL: http://codereview.chromium.org/6894003
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7917 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The profiler did not correctly identify when there was a JS frame
on the stack after an exception was thrown.
I also refactored the code to use PopTryHandler macro-instructions on all platforms
BUG=73722
TEST=No more valgrind errors related to v8::internal::StackFrameIterator.
Review URL: http://codereview.chromium.org/7019010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7910 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
1) Add new type JSProxy for representing proxy objects.
Currently devoid of functionality, i.e., all properties are undefined.
2) Some rudimentary global $Proxy functions to create proxies.
Next step: Hook up getProperty and getOwnProperty handlers. Will probably
require introducing a new LookupResult type, which is a mixture of
INTERCEPTOR (handles any property) and CALLBACK (calls back to JS).
Can we unify this somehow?
TODO: Should probably rename existing Proxy type to something like
"Foreign", to avoid confusion.
Review URL: http://codereview.chromium.org/6932068
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7887 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is IA32 only for now.
Added a random value to each assembler instance (JIT cookie) to be used for constant splitting. Added safe versions of setting a register with an immediate value and for pushing an immediate value. Used these functions where user controlled immediate values could be emitted in the code stream. I also used it for immediates which are an argument number even though the number of formal arguments is currently limited to 16k.
I found no compares directly with user controlled constants.
I am not sure whether the test is that useful, but it might catch some changes missing constant splitting.
Review URL: http://codereview.chromium.org//7005031
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7868 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This allows us to get rid of totally fake LAST_STRING_TYPE and makes
it possible to test for symbols.
I considered splitting HCheckInstanceType into two instructions, but
it seems nice to be able to hide the instance type implementation
details from the hydrogen level.
Review URL: http://codereview.chromium.org/6964011
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7840 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
If the result of an fast elements load is converted to an untagged
representation we can omit the hole check if the value is not used
anywhere else except for HChange instructions converting it to
an untagged representation since those will deoptimize for the hole
value anyway.
Review URL: http://codereview.chromium.org/6964012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7827 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Use a special slot for HContext, and fetch the value from there each time it is used. Allocate space for special slots in every HEnvironment. Fill them with constant undefined. Do not copy them to LEnvironment.
BUG=
TEST=
Review URL: http://codereview.chromium.org/6929066
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7807 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In my previous change I mixed up "compare" and "equals". This made us
miss the fast length check before comparing strings for equality.
Now we have a separate helper for "equals". It shares some of the
inner loop details with "compare". I'll see if this can be cleaned up
without making it unreadable.
Review URL: http://codereview.chromium.org/6928020
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7794 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The only difference to revision 7763 is the implementation in the
builtins file for arm and x64, plus a move of Array.prototype.toString
and Array.prototype.toLocaleString from should throw on null or
undefined to the non generic test cases in the function-call test (due
to us not currently supporting generic cases with these to functions)
Review URL: http://codereview.chromium.org/6928007
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7786 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
