[Liboil] Orc-0.4.7 released
ds at entropywave.com
Thu Aug 19 01:16:46 PDT 2010
ORC - The Oil Runtime Compiler
(and OIL stands for Optimized Inner Loops)
Entropy Wave Inc (http://entropywave.com/) presents Orc, the sucessor
to Liboil - The Library of Optimized Inner Loops.
Orc is a library and set of tools for compiling and executing
very simple programs that operate on arrays of data. The "language"
is a generic assembly language that represents many of the features
available in SIMD architectures, including saturated addition and
subtraction, and many arithmetic operations.
At this point, developers interested in using Orc should look at the
examples and try out a few Orc programs in an experimental branch
of their own projects. And provide feedback on how it works. There
will likely be some major changes in ease of use from a developer's
perspective over the next few releases.
The 0.4 series of Orc releases will be API and ABI compatible, and
will be incompatible with the 0.5 series when it comes out. The first
release of the 0.5 series is anticipated to coincide with the release
of GStreamer 1.0.
Changes in 0.4.7
- Lots of specialized new opcodes and opcode prefixes.
- Important fixes for ARM backend
- Improved emulation of programs (much faster)
- Implemented fallback rules for almost all opcodes for
SSE and NEON backends
- Performance improvements for SSE and NEON backends.
- Many fixes to make larger programs compile properly.
- 64-bit data types are now fully implemented, although
there are few operations on them.
Loads and stores are now handled by separate opcodes (loadb,
storeb, etc). For compatibility, these are automatically
included where necessary. This allowed new specialized
loading opcodes, for example, resampling a source array
for use in scaling images.
Opcodes may now be prefixed by "x2" or "x4", indicating that
a operation should be done on 2 or 4 parts of a proportionally
larger value. For example, "x4 addusb" performs 4 saturated
unsigned additions on each of the four bytes of 32-bit
quantities. This is useful in pixel operations.
The MMX backend is now (semi-) automatically generated from
the SSE backend.
The orcc tool has a new option "--inline", which creates inline
versions of the Orc stub functions. The orcc tool also recognizes
a new directive '.init', which instructs the compiler to generate
an initialization function, which when called at application init
time, compiles all the generated functions. This allows the
generated stub functions to avoid checking if the function has
already been compiled. The use of these two features can
dramatically decrease the cost of calling Orc functions.
Known Bugs: Orc generates code that crashes on 64-bit OS/X.
Plans for 0.4.8: (was 2.5 for 4 this time around, not too bad!)
Document all the new features in 0.4.7. Instruction scheduler.
Code and API cleanup.
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