This is a roll forward of D101895 with two additional fixes:
Original Patch description:
> This is a follow up on D101524 which:
>
> - simplifies cpu features detection and usage,
> - flattens target dependent optimizations so it's obvious which implementations are generated,
> - provides an implementation targeting the host (march/mtune=native) for the mem* functions,
> - makes sure all implementations are unittested (provided the host can run them).
Additional fixes:
- Fix uninitialized ALL_CPU_FEATURES
- Use non pseudo microarch as it is only supported from Clang 12 on
Differential Revision: https://reviews.llvm.org/D102233
This reverts commit 541f107871bc9c020925a6e5342542a47c902d12 as the bots
are failing with unknown architecture "x86-64-v*". Will let the original
author decide on the right course of action to correct the problem and
reland.
This is a follow up on D101524 which:
- simplifies cpu features detection and usage,
- flattens target dependent optimizations so it's obvious which implementations are generated,
- provides an implementation targeting the host (march/mtune=native) for the mem* functions,
- makes sure all implementations are unittested (provided the host can run them),
- makes sure all implementations are benchmarkable (provided the host can run them).
Differential Revision: https://reviews.llvm.org/D101895
Current implementation defines LIBC_TARGET_MACHINE with the use of CMAKE_SYSTEM_PROCESSOR.
Unfortunately CMAKE_SYSTEM_PROCESSOR is OS dependent and can produce different results.
An evidence of this is the various matchers used to detect whether the architecture is x86.
This patch normalizes LIBC_TARGET_MACHINE and renames it LIBC_TARGET_ARCHITECTURE.
I've added many architectures but we may want to limit ourselves to x86 and ARM.
Differential Revision: https://reviews.llvm.org/D101524
Aligned copy used to be 'destination aligned' for x86 but this decision was reverted in D93457 where we noticed that it was better for ARM to be 'source aligned'.
More benchmarking confirmed that it can be up to 30% faster to align copy to destination for x86. This Patch offers both implementations and switches x86 back to destination aligned.
It also fixes alignment to 32 byte on x86.
Differential Revision: https://reviews.llvm.org/D101296
This is needed to prevent asan/msan instrumentation to redirect CopyBlock to `__asan_memcpy` (resp. `__msan_memcpy`).
These functions would then differ operation to `memcpy` which leads to reentrancy issues.
With this patch, `memcpy` is fully instrumented and covered by asan/msan.
If this turns out to be too expensive, instrumentation can be selectively or fully disabled through the use of the `__attribute__((no_sanitize(address, memory)))` annotation.
Differential Revision: https://reviews.llvm.org/D99598
We want to be able to build and test the string functions in contexts
like that of Fuchsia where LLVM pieces like tablegen are not available.
Since header generation uses tablegen, we are removing the dependency on
headergen here.
Reviewed By: gchatelet
Differential Revision: https://reviews.llvm.org/D97363
`ssize_t` is from POSIX and is not standard unfortunately.
Rewritting the code so it doesn't depend on it.
Differential Revision: https://reviews.llvm.org/D94760
- Adds LLVM_LIBC_IS_DEFINED macro to libc/src/__support/common.h
- Adds a few knobs to memcpy to help with experimentations:
- LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB replaces the implementation with a single call to rep;movsb
- LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE customizes where the usage of rep;movsb
Differential Revision: https://reviews.llvm.org/D94692
Use `memcpy` rather than copying bytes one by one, for there might be large
size structs to move.
Reviewed By: gchatelet, sivachandra
Differential Revision: https://reviews.llvm.org/D93195
Summary:
The new macro also inserts the C alias for the C++ implementations
without needing an objcopy based post processing step. The CMake
rules have been updated to reflect this. More CMake cleanup can be
taken up in future rounds and appropriate TODOs have been added for them.
Reviewers: mcgrathr, sivachandra
Subscribers:
We used to align destination buffer instead of source buffer for the loop of block copy.
This is a mistake.
Differential Revision: https://reviews.llvm.org/D93457
This switches all of the files in src/string, src/math, and
test/src/math from using relative paths (e.g. `#include “include/string.h”`)
to global paths (e.g. `#include <string.h>`) to make bringing up those
functions on other platforms, such as fuchsia, easier.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D91394
This revision removes dependencies that exist between different string functions. This allows for the libc user to use a specific function X of this library without also depending on Y and Z.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D87421
Along that way, platform specific options to memcpy, memset and bzero
builds have been enclosed in conditionals. Also, the optimization level
has been set to -O2 for the memory function builds to actually see the
static functions inlined.
Reviewers: gchatelet
Differential Revision: https://reviews.llvm.org/D81621
Conditionally adding subdirectories was missed in a few places previously.
This change adds the conditionals. A sub-directory was being added
needlessly in another place. That has been removed.
Summary: This is a NFC, it aims at simplifying both the code and build files.
Reviewers: abrachet, sivachandra
Subscribers: mgorny, tschuett, ecnelises, libc-commits, courbet
Tags: #libc-project
Differential Revision: https://reviews.llvm.org/D80291
Only targets setup by the special LLVM libc rules now have fully
qualified names. The naming style is similar to fully qualified names in
Python.
Reviewers: abrachet, PaulkaToast, phosek
Differential Revision: https://reviews.llvm.org/D77340
Summary:
Made all header files consistent based of this documentation: https://llvm.org/docs/CodingStandards.html#file-headers.
And did the same for all source files top of file comments.
Reviewers: sivachandra, abrachet
Reviewed By: sivachandra, abrachet
Subscribers: MaskRay, tschuett, libc-commits
Tags: #libc-project
Differential Revision: https://reviews.llvm.org/D77533
Summary: This should fix the call to a non internal libc function.
Reviewers: sivachandra, abrachet
Reviewed By: sivachandra
Subscribers: xbolva00, mgorny, MaskRay, tschuett, libc-commits
Tags: #libc-project
Differential Revision: https://reviews.llvm.org/D77279
