llvm-project.git/libc/src/string/memory_utils/utils.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] Add `-Wno-sign-conversion` & re-attempt `-Wconversion` (#129811)

2025-03-10T15:57:09+00:00

Relates to
https://github.com/llvm/llvm-project/issues/119281#issuecomment-2699470459

Revert "[libc] Enable -Wconversion for tests. (#127523)"

2025-03-05T21:42:40+00:00

This reverts commit 1e6e845d49a336e9da7ca6c576ec45c0b419b5f6 because it
changed the 1st parameter of adjust() to be unsigned, but libc itself
calls adjust() with a negative argument in align_backward() in
op_generic.h.

[libc] Enable -Wconversion for tests. (#127523)

2025-03-04T15:24:35+00:00

Relates to: #119281

[libc] Fix all imports of src/string/memory_utils (#114939)

2025-02-05T17:24:44+00:00

Fixed imports for all files *within* `libc/src/string/memory_utils`.
Note: This doesn't include **all** files that need to be fixed.

Fixes #86579

[libc] Rename libc/src/__support/endian.h to endian_internal.h (#115950)

2024-11-13T18:28:07+00:00

This prevents a conflict with the Linux system endian.h when built in
overlay mode for CPP files in __support.

This issue appeared in PR #106259.

[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][NFC] Allow compilation of `memcpy` with `-m32` (#93790)

2024-05-31T08:48:38+00:00

Needed to support i386 (#93709).