Home | History | Annotate | only in /external/vixl
Up to higher level directory
NameDateSize
.gitignore03-Dec-2014115
Android.mk03-Dec-20145.3K
benchmarks/03-Dec-2014
doc/03-Dec-2014
examples/03-Dec-2014
LICENCE03-Dec-20141.6K
MODULE_LICENSE_BSD_LIKE03-Dec-20140
README.md03-Dec-20144K
SConstruct03-Dec-20146.9K
src/03-Dec-2014
test/03-Dec-2014
tools/03-Dec-2014

README.md

      1 VIXL: AArch64 Runtime Code Generation Library Version 1.4
      2 =========================================================
      3 
      4 Contents:
      5 
      6  * Requirements
      7  * Overview
      8  * Known limitations
      9  * Usage
     10 
     11 
     12 Requirements
     13 ============
     14 
     15 To build VIXL the following software is required:
     16 
     17  1. Python 2.7
     18  2. SCons 2.0
     19  3. GCC 4.4+
     20 
     21 A 64-bit host machine is required, implementing an LP64 data model. VIXL has
     22 only been tested using GCC on Ubuntu systems.
     23 
     24 To run the linter stage of the tests, the following software is also required:
     25 
     26  1. Git
     27  2. [Google's `cpplint.py`][cpplint]
     28 
     29 Refer to the 'Usage' section for details.
     30 
     31 
     32 Overview
     33 ========
     34 
     35 VIXL is made of three components.
     36 
     37  1. A programmatic assembler to generate A64 code at runtime. The assembler
     38     abstracts some of the constraints of the A64 ISA, for example most
     39     instructions support any immediate.
     40  2. A disassembler which can print any instruction emitted by the assembler.
     41  3. A simulator which can simulate any instruction emitted by the assembler.
     42     The simulator allows generated code to be run on another architecture
     43     without the need for a full ISA model.
     44 
     45 The VIXL git repository can be found [on GitHub][vixl]. Changes from previous
     46 versions of VIXL can be found in the [Changelog](doc/changelog.md).
     47 
     48 
     49 Known Limitations
     50 =================
     51 
     52 VIXL was developed to target JavaScript engines so a number of features from A64
     53 were deemed unnecessary:
     54 
     55  * No Advanced SIMD support.
     56  * Limited rounding mode support for floating point.
     57  * Limited support for synchronisation instructions.
     58  * Limited support for system instructions.
     59  * A few miscellaneous integer and floating point instructions are missing.
     60 
     61 The VIXL simulator supports only those instructions that the VIXL assembler can
     62 generate. The `doc` directory contains a
     63 [list of supported instructions](doc/supported-instructions.md).
     64 
     65 The VIXL simulator was developed to run on 64-bit amd64 platforms. Whilst it
     66 builds and mostly works for 32-bit x86 platforms, there are a number of
     67 floating-point operations which do not work correctly, and a number of tests
     68 fail as a result.
     69 
     70 Usage
     71 =====
     72 
     73 
     74 Running all Tests
     75 -----------------
     76 
     77 The helper script `tools/presubmit.py` will build and run every test that is
     78 provided with VIXL, in both release and debug mode. It is a useful script for
     79 verifying that all of VIXL's dependencies are in place and that VIXL is working
     80 as it should.
     81 
     82 By default, the `tools/presubmit.py` script runs a linter to check that the
     83 source code conforms with the code style guide, and to detect several common
     84 errors that the compiler may not warn about. This is most useful for VIXL
     85 developers. The linter has the following dependencies:
     86 
     87  1. Git must be installed, and the VIXL project must be in a valid Git
     88     repository, such as one produced using `git clone`.
     89  2. `cpplint.py`, [as provided by Google][cpplint], must be available (and
     90     executable) on the `PATH`. Only revision 104 has been tested with VIXL.
     91 
     92 It is possible to tell `tools/presubmit.py` to skip the linter stage by passing
     93 `--nolint`. This removes the dependency on `cpplint.py` and Git. The `--nolint`
     94 option is implied if the VIXL project is a snapshot (with no `.git` directory).
     95 
     96 
     97 Building and Running the Benchmarks
     98 -----------------------------------
     99 
    100 There are two very basic benchmarks provided with VIXL:
    101 
    102  1. bench\_dataop, emitting adds
    103  2. bench\_branch, emitting branches
    104 
    105 To build one benchmark: `scons target=bench_xxx`, then run it as
    106 `./bench_xxx_sim <number of iterations>`. The benchmarks do not report a
    107 figure; they should be timed using the `time` command.
    108 
    109 
    110 Getting Started
    111 ---------------
    112 
    113 A short introduction to using VIXL can be found [here](doc/getting-started.md).
    114 Example source code is provided in the `examples` directory. Build this using
    115 `scons target=examples` from the root directory.
    116 
    117 
    118 
    119 [cpplint]: https://google-styleguide.googlecode.com/svn-history/r104/trunk/cpplint/cpplint.py
    120            "Google's cpplint.py script."
    121 
    122 [vixl]: https://github.com/armvixl/vixl
    123         "The VIXL repository on GitHub."
    124