vasilito
cb424d7448
verify-patch-sanity.py validates every active recipe .patch has internally- consistent hunk line counts — catching the 'malformed patch at line N' failure at commit/CI/preflight time instead of hours into a cook. This cycle hit that class three times (qtwaylandscanner, sddm, xwayland), each only discovered when cookbook tried to apply the patch. Running it across the repo found 29 latent malformed patches (validated against GNU patch: e.g. relibc/P3-sysv-ipc reproduces 'malformed patch at line 22'). They were harmless only because they sit in vendored recipes (baked, not re- applied) — but would fail on any version-bump re-derivation. --fix recounts the hunk headers (body untouched) and repaired all 29. Wired into build-preflight.sh (Phase 1.0D) and redbear-ci.yml, with a unit test (test-patch-sanity.sh). Skips archived/legacy trees and unvalidatable formats (empty placeholders, bare-@@ git hunks).
52 lines
2.3 KiB
ReStructuredText
52 lines
2.3 KiB
ReStructuredText
.. _libc_gpu_motivation:
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==========================
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Motivation and Limitations
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==========================
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.. contents:: Table of Contents
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:depth: 4
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:local:
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Motivation
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==========
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This project aims to provide a large subset of the C standard library to users
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of GPU accelerators. We deliberately choose to only implement a subset of the C
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library as some features are not expressly useful or easily implemented on the
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GPU. This will be discussed further in `Limitations <libc_gpu_limitations>`_.
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The main motivation behind this project is to provide the well understood C
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library as a firm base for GPU development.
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The main idea behind this project is that programming GPUs can be as
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straightforward as programming on CPUs. This project aims to validate the GPU as
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a more general-purpose target. The implementations here will also enable more
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complex implementations of other libraries on the GPU, such as ``libc++``.
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Host services and C library features are currently provided sparsely by the
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different GPU vendors. We wish to provide these functions more completely and
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make their implementations available in a common format. This is useful for
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targets like OpenMP offloading or SYCL which wish to unify the offloading
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toolchain. We also aim to provide these functions in a format compatible with
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offloading in ``Clang`` so that we can treat the C library for the GPU as a
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standard static library.
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A valuable use for providing C library features on the GPU is for testing. For
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this reason we build `tests on the GPU <libc_gpu_testing>`_ that can run a unit
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test as if it were being run on the CPU. This also helps users port applications
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that traditionally were run on the CPU. With this support, we can expand test
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coverage for the GPU backend to the existing LLVM C library tests.
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.. _libc_gpu_limitations:
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Limitations
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===========
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We only implement a subset of the standard C library. The GPU does not
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currently support thread local variables in all cases, so variables like
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``errno`` are atomic and global. Furthermore, the GPU under the OpenCL execution
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model cannot safely provide a mutex interface. This means that features like
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file buffering are not implemented on the GPU. We can also not easily provide
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threading features on the GPU due to the execution model so these will be
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ignored, as will features like ``locale`` or ``time``.
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