{"id":20164912,"url":"https://github.com/multi-os-engine/vixl","last_synced_at":"2026-06-12T07:32:01.942Z","repository":{"id":72751173,"uuid":"65292466","full_name":"multi-os-engine/vixl","owner":"multi-os-engine","description":"Multi-OS Engine: VIXL","archived":false,"fork":false,"pushed_at":"2022-07-23T15:25:11.000Z","size":114462,"stargazers_count":1,"open_issues_count":0,"forks_count":1,"subscribers_count":6,"default_branch":"moe-master","last_synced_at":"2025-01-13T14:32:57.296Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"https://multi-os-engine.org","language":"C","has_issues":false,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"other","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/multi-os-engine.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2016-08-09T12:17:20.000Z","updated_at":"2017-09-30T10:49:27.000Z","dependencies_parsed_at":"2023-03-19T11:18:10.128Z","dependency_job_id":null,"html_url":"https://github.com/multi-os-engine/vixl","commit_stats":null,"previous_names":[],"tags_count":181,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/multi-os-engine%2Fvixl","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/multi-os-engine%2Fvixl/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/multi-os-engine%2Fvixl/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/multi-os-engine%2Fvixl/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/multi-os-engine","download_url":"https://codeload.github.com/multi-os-engine/vixl/tar.gz/refs/heads/moe-master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":241600490,"owners_count":19988715,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-11-14T00:36:04.689Z","updated_at":"2026-06-12T07:31:56.901Z","avatar_url":"https://github.com/multi-os-engine.png","language":"C","funding_links":[],"categories":[],"sub_categories":[],"readme":"VIXL: AArch64 Runtime Code Generation Library Version 1.10\n==========================================================\n\nContents:\n\n * Overview\n * Licence\n * Requirements\n * Known limitations\n * Usage\n\n\nOverview\n========\n\nVIXL contains three components.\n\n 1. A programmatic **assembler** to generate A64 code at runtime. The assembler\n    abstracts some of the constraints of the A64 ISA; for example, most\n    instructions support any immediate.\n 2. A **disassembler** that can print any instruction emitted by the assembler.\n 3. A **simulator** that can simulate any instruction emitted by the assembler.\n    The simulator allows generated code to be run on another architecture\n    without the need for a full ISA model.\n\nThe VIXL git repository can be found [on GitHub][vixl].\n\nChanges from previous versions of VIXL can be found in the\n[Changelog](doc/changelog.md).\n\n\nLicence\n=======\n\nThis software is covered by the licence described in the [LICENCE](LICENCE)\nfile.\n\n\nRequirements\n============\n\nTo build VIXL the following software is required:\n\n 1. Python 2.7\n 2. SCons 2.0\n 3. GCC 4.8+ or Clang 3.4+\n\nA 64-bit host machine is required, implementing an LP64 data model. VIXL has\nbeen tested using GCC on AArch64 Debian, GCC and Clang on amd64 Ubuntu\nsystems.\n\nTo run the linter stage of the tests, the following software is also required:\n\n 1. Git\n 2. [Google's `cpplint.py`][cpplint]\n\nRefer to the 'Usage' section for details.\n\n\nKnown Limitations\n=================\n\nVIXL was developed for JavaScript engines so a number of features from A64 were\ndeemed unnecessary:\n\n * Limited rounding mode support for floating point.\n * Limited support for synchronisation instructions.\n * Limited support for system instructions.\n * A few miscellaneous integer and floating point instructions are missing.\n\nThe VIXL simulator supports only those instructions that the VIXL assembler can\ngenerate. The `doc` directory contains a\n[list of supported instructions](doc/supported-instructions.md).\n\nThe VIXL simulator was developed to run on 64-bit amd64 platforms. Whilst it\nbuilds and mostly works for 32-bit x86 platforms, there are a number of\nfloating-point operations which do not work correctly, and a number of tests\nfail as a result.\n\nDebug Builds\n------------\n\nYour project's build system must define `VIXL_DEBUG` (eg. `-DVIXL_DEBUG`)\nwhen using a VIXL library that has been built with debug enabled.\n\nSome classes defined in VIXL header files contain fields that are only present\nin debug builds, so if `VIXL_DEBUG` is defined when the library is built, but\nnot defined for the header files included in your project, you will see runtime\nfailures.\n\nExclusive-Access Instructions\n-----------------------------\n\nAll exclusive-access instructions are supported, but the simulator cannot\naccurately simulate their behaviour as described in the ARMv8 Architecture\nReference Manual.\n\n * A local monitor is simulated, so simulated exclusive loads and stores execute\n   as expected in a single-threaded environment.\n * The global monitor is simulated by occasionally causing exclusive-access\n   instructions to fail regardless of the local monitor state.\n * Load-acquire, store-release semantics are approximated by issuing a host\n   memory barrier after loads or before stores. The built-in\n   `__sync_synchronize()` is used for this purpose.\n\nThe simulator tries to be strict, and implements the following restrictions that\nthe ARMv8 ARM allows:\n\n * A pair of load-/store-exclusive instructions will only succeed if they have\n   the same address and access size.\n * Most of the time, cache-maintenance operations or explicit memory accesses\n   will clear the exclusive monitor.\n    * To ensure that simulated code does not depend on this behaviour, the\n      exclusive monitor will sometimes be left intact after these instructions.\n\nInstructions affected by these limitations:\n  `stxrb`, `stxrh`, `stxr`, `ldxrb`, `ldxrh`, `ldxr`, `stxp`, `ldxp`, `stlxrb`,\n  `stlxrh`, `stlxr`, `ldaxrb`, `ldaxrh`, `ldaxr`, `stlxp`, `ldaxp`, `stlrb`,\n  `stlrh`, `stlr`, `ldarb`, `ldarh`, `ldar`, `clrex`.\n\n\nUsage\n=====\n\nRunning all Tests\n-----------------\n\nThe helper script `tools/test.py` will build and run every test that is provided\nwith VIXL, in both release and debug mode. It is a useful script for verifying\nthat all of VIXL's dependencies are in place and that VIXL is working as it\nshould.\n\nBy default, the `tools/test.py` script runs a linter to check that the source\ncode conforms with the code style guide, and to detect several common errors\nthat the compiler may not warn about. This is most useful for VIXL developers.\nThe linter has the following dependencies:\n\n 1. Git must be installed, and the VIXL project must be in a valid Git\n    repository, such as one produced using `git clone`.\n 2. `cpplint.py`, [as provided by Google][cpplint], must be available (and\n    executable) on the `PATH`.\n\nIt is possible to tell `tools/test.py` to skip the linter stage by passing\n`--nolint`. This removes the dependency on `cpplint.py` and Git. The `--nolint`\noption is implied if the VIXL project is a snapshot (with no `.git` directory).\n\n\nBuilding and Running the Benchmarks\n-----------------------------------\n\nThere are three very basic benchmarks provided with VIXL:\n\n 1. bench-dataop, emitting adds\n 2. bench-branch, emitting branches\n 3. bench-branch-link, emitting branch-links\n\nBuild these benchmarks using `scons bench-dataop`, `scons bench-branch` and\n`scons bench-branch-link`. This will produce binaries called\n`bench-dataop_sim`, `bench-branch_sim` and `bench-branch-link_sim`. Run these\nwith an iteration count argument, for example `./bench-dataop_sim 10000000`. The\nbenchmarks do not report a result; time them using the UNIX `time` command.\n\nBuild the benchmarks natively for execution on an AArch64 target using `scons\n\u003cbenchmark name\u003e simulator=off`. This will produce binaries called\n`bench-dataop`, `bench-branch` and `bench-branch-link`. Run and time these in\nthe same way as the simulator versions.\n\n\nGetting Started\n---------------\n\nA short introduction to using VIXL can be found [here](doc/getting-started.md).\nExample source code is provided in the [examples](examples) directory. You can\nbuild all the examples with `scons examples` from the root directory, or use\n`scons --help` to get a detailed list of available build targets.\n\n\nUsing VIXL\n----------\n\nIn addition to [getting started](doc/getting-started.md) and the\n[examples](examples), you can find documentation and guides on various topics\nthat may be helpful [here](doc/topics/index.md).\n\n\n\n\n\n[cpplint]: http://google-styleguide.googlecode.com/svn/trunk/cpplint/cpplint.py\n           \"Google's cpplint.py script.\"\n\n[vixl]: https://github.com/armvixl/vixl\n        \"The VIXL repository on GitHub.\"\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmulti-os-engine%2Fvixl","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fmulti-os-engine%2Fvixl","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmulti-os-engine%2Fvixl/lists"}