llvm-project.git/libc/src/string/memory_utils/inline_memcpy.h, branch users/nico/python-2

[libc] Improve memcpy for ARM Cortex-M supporting unaligned accesses. (#144872)

2025-06-26T08:18:02+00:00

This implementation has been compiled with the [pigweed toolchain](https://pigweed.dev/toolchain.html) and tested on:
 - Raspberry Pi Pico 2 with the following options\
`--target=armv8m.main-none-eabi`
`-march=armv8m.main+fp+dsp`
`-mcpu=cortex-m33` 
 - Raspberry Pi Pico with the following options\
`--target=armv6m-none-eabi`
`-march=armv6m`
`-mcpu=cortex-m0+` 

They both compile down to a little bit more than 200 bytes and are between 2 and 10 times faster than byte per byte copies.

For best performance the following options can be set in the `libc/config/baremetal/arm/config.json`
```
{
  "codegen": {
    "LIBC_CONF_KEEP_FRAME_POINTER": {
      "value": false
    }
  },
  "general": {
    "LIBC_ADD_NULL_CHECKS": {
      "value": false
    }
  }
}
```

[libc] Default to `byte_per_byte` instead of erroring (#131340)

2025-03-14T15:10:53+00:00

Summary:
Right now a lot of the memory functions error if we don't have specific
handling for them. This is weird because we have a generic
implementation that should just be used whenever someone hasn't written
a more optimized version. This allows us to use the `libc` headers with
more architectures from the `shared/` directory without worrying about
it breaking.

[libc] Clean up some include in `libc`. (#110980)

2024-10-06T15:08:34+00:00

The patch primarily cleans up some incorrect includes. The `LIBC_INLINE`
macro is defined in `attributes.h`, not `config.h`. There appears to be
no need to change the CMake and Bazel build files.

[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration (#98597)

2024-07-12T16:28:41+00:00

This is a part of #97655.

Revert "[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration" (#98593)

2024-07-12T07:12:13+00:00

Reverts llvm/llvm-project#98075

bots are broken

[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration (#98075)

2024-07-11T19:35:22+00:00

This is a part of #97655.

[libc] Remove unnecessary call in memfunction dispatchers (#75800)

2023-12-19T12:57:44+00:00

Before this patch the compiler could generate unnecessary calls to the
selected implementation.
https://clang.llvm.org/docs/AttributeReference.html#flatten

[libc] Change the GPU to use builtin memory functions (#68003)

2023-10-04T12:02:55+00:00

Summary:
The GPU build is special in the sense that we always know that
up-to-date `clang` is always going to be the compiler. This allows us to
rely directly on builtins, which allow us to push a lot of this
complexity into the backend. Backend implementations are favored on
the GPU because it allows us to do a lot more target specific
optimizations. This patch changes over the common memory functions to
use builtin versions when building for AMDGPU or NVPTX.

[libc] Mass replace enclosing namespace (#67032)

2023-09-26T09:45:04+00:00

This is step 4 of
https://discourse.llvm.org/t/rfc-customizable-namespace-to-allow-testing-the-libc-when-the-system-libc-is-also-llvms-libc/73079

[libc][NFC] Rename files

2023-07-19T09:06:29+00:00

This patch mostly renames files so it better reflects the function they declare.

Reviewed By: michaelrj

Differential Revision: https://reviews.llvm.org/D155607