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Diffstat (limited to 'vendor/memchr/README.md')
| -rw-r--r-- | vendor/memchr/README.md | 25 |
1 files changed, 7 insertions, 18 deletions
diff --git a/vendor/memchr/README.md b/vendor/memchr/README.md index 77a7a0f5b..54dabd585 100644 --- a/vendor/memchr/README.md +++ b/vendor/memchr/README.md @@ -35,30 +35,19 @@ memchr links to the standard library by default, but you can disable the memchr = { version = "2", default-features = false } ``` -On x86 platforms, when the `std` feature is disabled, the SSE2 accelerated -implementations will be used. When `std` is enabled, AVX accelerated +On `x86_64` platforms, when the `std` feature is disabled, the SSE2 accelerated +implementations will be used. When `std` is enabled, AVX2 accelerated implementations will be used if the CPU is determined to support it at runtime. -### Using libc - -`memchr` is a routine that is part of libc, although this crate does not use -libc by default. Instead, it uses its own routines, which are either vectorized -or generic fallback routines. In general, these should be competitive with -what's in libc, although this has not been tested for all architectures. If -using `memchr` from libc is desirable and a vectorized routine is not otherwise -available in this crate, then enabling the `libc` feature will use libc's -version of `memchr`. - -The rest of the functions in this crate, e.g., `memchr2` or `memrchr3` and the -substring search routines, will always use the implementations in this crate. -One exception to this is `memrchr`, which is an extension in `libc` found on -Linux. On Linux, `memrchr` is used in precisely the same scenario as `memchr`, -as described above. +SIMD accelerated routines are also available on the `wasm32` and `aarch64` +targets. The `std` feature is not required to use them. +When a SIMD version is not available, then this crate falls back to +[SWAR](https://en.wikipedia.org/wiki/SWAR) techniques. ### Minimum Rust version policy -This crate's minimum supported `rustc` version is `1.41.1`. +This crate's minimum supported `rustc` version is `1.60.0`. The current policy is that the minimum Rust version required to use this crate can be increased in minor version updates. For example, if `crate 1.0` requires |