Until now we conservatively chose a double representation if
at least one use occurs in a double operation. This causes performance
degradation in many cases where there are mixes uses (integer and double)
e.g.:
for (int i = 0; i < 10; i++) {
var t = i / 3.5;
a[i] = t;
}
where the use in i/3 requires a double, where as the keyed store requires i
as an integer.
For these cases we want to have i as an integer and convert it only before the
double division.
In order to avoid unconditional deoptimization in some rare cases, we check
phis if there is any conversion that will always fail when converting a
heap-number constant to int32.
Review URL: http://codereview.chromium.org/6905166
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7757 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Always use CpuFeaturesImpliedByCompiler() when selecting CPU features. This checks both for CAN_USE_ARMV7_INSTRUCTIONS and CAN_USE_VFP_INSTRUCTIONS and for GCC preprocessor symbols. This will support using the CAN_USE_XXX for a simulator build used for generating a snapshot followed by a crosscompile using -march= and -mfpu= for selecting the (minimal) target device CPU features. The snapshot will use instructions based on the CAN_USE_XXX whereas the target will at least use features based on both CAN_USE_XXX and -march= and -mfpu=, but will try runtime CPU feature detection a well looking for somethis better.
Remove the compiler based CPU feature detection from the OS::CpuFeaturesImpliedByPlatform() as it did not belong there. Also was already in the CpuFeaturesImpliedByCompiler().
Add the variable 'v8_can_use_vfp_instructions' to the GYP file which can be used to turn on CAN_USE_VFP_INSTRUCTIONS when building V8. I did not add any -mfpu= cflags for this, as there are several options here (e.g. vfp and neon).
R=erik.corry@gmail.com, karlklose@chromium.org
BUG=none
TEST=none
Review URL: http://codereview.chromium.org//6904164
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7754 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
- It was calculating start_block and end_block incorrectly.
- It was not considering the case when end_block is a loop header itself when searching for the header of the outermost loop.
These bugs do not affect correctness of the allocation but can severely degrade it's quality (cause spills in loop bodies).
Review URL: http://codereview.chromium.org/6901148
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7737 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Switched to using binary low-level log instead of the textual log used
by the ticks processor. The binary log contains code-related events,
code object names, and their bodies. When writing to the log we ask
glibc to use a larger buffer. To avoid complex processing of the
snapshot log (which is still textual) the serializer emits final
snapshot position to code name mappings that can be quickly be read
without replaying the snapshot log. (This might be useful for the
ticks processor.)
Review URL: http://codereview.chromium.org/6904127
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7729 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This is for mobile platforms where application footprint size is
important. To avoid including compression libraries into V8, we assume
that the host machine have them (true for Linux), and rely on embedder
to provide decompressed data.
Currently, only snapshot data can be comressed. It is also possible to
compress libraries sources, but it is more involved and will be
addressed in another CL.
BUG=none
TEST=none
Review URL: http://codereview.chromium.org/6901090
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7724 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Add option armeabi to the SCons build for selecting the floating point variant to use. Also add externally defined CCFLAGS environment for all targets. Run test.py with option -S armeabi=hardfloat to test with hardfloat enabled.
Make selecting hardfloat EABI variant a build-time option instead of a runtime option.
Add a simple check of the EABI variant during V8 initialization to exit if the compilation was not configured correctly. The reason for this is that GCC does not provide a compile time symbol defining the EABI variant. This check is not fool-proof as it cannot check the compilation configuration used for the snapshot if any.
R=karlklose@chromium.org, erik.corry@gmail.com
BUG=none
TEST=none
Review URL: http://codereview.chromium.org//6905098
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7715 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The corner case is calling a function named 'eval' that is looked up at
runtime and found in a non-global context (but not an extension object).
The bug is that we used the function itself as the receiver rather than
using the global object.
R=ager@chromium.org
TEST=has been added to the eval mjsunit test
Review URL: http://codereview.chromium.org/6893057
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7696 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
