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).
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ReStructuredText
150 lines
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========
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stdfix.h
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========
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.. include:: ../check.rst
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Standards and Goals
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-------------------
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- stdfix.h is specified in the `ISO/IEC TR 18037:2008 <https://www.iso.org/standard/51126.html>`_,
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C extensions to support embedded processors .
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- Its `specifications <https://standards.iso.org/ittf/PubliclyAvailableStandards/c051126_ISO_IEC_TR_18037_2008.zip>`_.
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- Our goal is to implement a complete set of math functions for fixed point
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types, most of them are currently not included in the ISO/IEC TR
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18037:2008 standard. Our math functions for fixed point types are modeled
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after the C99/C23 math functions for floating point types.
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---------------
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Source location
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---------------
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- The main source for fixed-point functions is located at:
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``libc/src/stdfix`` with subdirectories for internal implementations.
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---------------------
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Implementation Status
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---------------------
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Requirements
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============
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- In order to build LLVM libc to support fixed-point arithmetics, we need the
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compiler to support the basic fixed-point types `_Fract` and `_Accum` in
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C++.
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- For the users to be able to use the generated headers, their compiler needs
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to support `_Fract` and `_Accum` types in C or C++.
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- This compiler support is checked at the beginning of
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`libc/include/llvm-libc-macros/stdfix-macros.h <https://github.com/llvm/llvm-project/tree/main/libc/include/llvm-libc-macros/stdfix-macros.h>`_.
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Predefined Macros
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=================
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- We use the macro `LIBC_COMPILER_HAS_FIXED_POINT` to specify whether the
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compiler support the fixed-point types.
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- Other predefined precision macros specified in section 7.18a.3 are defined
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in `libc/include/llvm-libc-macros/stdfix-macros.h <https://github.com/llvm/llvm-project/tree/main/libc/include/llvm-libc-macros/stdfix-macros.h>`_
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using the default configuration of `typical desktop processor` in section
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A.3.
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Fixed-point Arithmetics
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=======================
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The following functions are included in the ISO/IEC TR 18037:2008 standard.
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+---------------+------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------+
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| Function Name | _Fract (r) | _Accum (k) |
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| +------------------------------+----------------------------+------------------------------+------------------------------+----------------------------+------------------------------+
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| | short (hr) | _ (r) | long (lr) | short (hk) | _ (k) | long (lk) |
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| +----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| | unsigned (uhr) | signed (hr) | unsigned (ur) | signed (r) | unsigned (ulr) | signed (lr) | unsigned (uhk) | signed (hk) | unsigned (uk) | signed (k) | unsigned (ulk) | signed (lk) |
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+===============+================+=============+===============+============+================+=============+================+=============+===============+============+================+=============+
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| abs | | |check| | | |check| | | |check| | | |check| | | |check| | | |check| |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| bits\* | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| \*bits | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| countls | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| divi\* | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| idiv\* | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| muli | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| \*divi | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| round | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| | |check| |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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================== =========
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Type Generic Macro Available
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================== =========
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absfx |check|
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countlsfx |check|
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roundfx |check|
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================== =========
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Higher math functions
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=====================
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The following math functions are modeled after C99/C23 math functions for
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floating point types, but are not part of the ISO/IEC TR 18037:2008 spec.
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+---------------+------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------+
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| Function Name | _Fract (r) | _Accum (k) |
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| +------------------------------+----------------------------+------------------------------+------------------------------+----------------------------+------------------------------+
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| | short (hr) | _ (r) | long (lr) | short (hk) | _ (k) | long (lk) |
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| +----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| | unsigned (uhr) | signed (hr) | unsigned (ur) | signed (r) | unsigned (ulr) | signed (lr) | unsigned (uhk) | signed (hk) | unsigned (uk) | signed (k) | unsigned (ulk) | signed (lk) |
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+===============+================+=============+===============+============+================+=============+================+=============+===============+============+================+=============+
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| cos | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| exp | | | | | | | | |check| | | |check| | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| log | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| sin | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| sqrt | |check| | | |check| | | |check| | | |check| | | |check| | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| tan | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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Conversion Functions
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====================
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The following conversion functions are included in the ISO/IEC TR 18037:2008
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standard.
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+---------------+------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------+
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| Function Name | _Fract (r) | _Accum (k) |
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| +------------------------------+----------------------------+------------------------------+------------------------------+----------------------------+------------------------------+
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| | short (hr) | _ (r) | long (lr) | short (hk) | _ (k) | long (lk) |
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| +----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| | unsigned (uhr) | signed (hr) | unsigned (ur) | signed (r) | unsigned (ulr) | signed (lr) | unsigned (uhk) | signed (hk) | unsigned (uk) | signed (k) | unsigned (ulk) | signed (lk) |
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+===============+================+=============+===============+============+================+=============+================+=============+===============+============+================+=============+
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| fprintf | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| fscanf | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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| strtofx | | | | | | | | | | | | |
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+---------------+----------------+-------------+---------------+------------+----------------+-------------+----------------+-------------+---------------+------------+----------------+-------------+
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Warnings
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========
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This is currently a work-in-progress, its headers, macros, and ABI are still unstable, and might be modified.
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