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Diffstat (limited to 'lib/README.md')
| -rw-r--r-- | lib/README.md | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/lib/README.md b/lib/README.md index 792729b1f9ba..0062c0d63e04 100644 --- a/lib/README.md +++ b/lib/README.md @@ -27,10 +27,10 @@ Enabling multithreading requires 2 conditions : Both conditions are automatically applied when invoking `make lib-mt` target. When linking a POSIX program with a multithreaded version of `libzstd`, -note that it's necessary to request the `-pthread` flag during link stage. +note that it's necessary to invoke the `-pthread` flag during link stage. Multithreading capabilities are exposed -via the [advanced API defined in `lib/zstd.h`](https://github.com/facebook/zstd/blob/v1.3.8/lib/zstd.h#L592). +via the [advanced API defined in `lib/zstd.h`](https://github.com/facebook/zstd/blob/v1.4.3/lib/zstd.h#L351). #### API @@ -112,6 +112,17 @@ The file structure is designed to make this selection manually achievable for an will expose the deprecated `ZSTDMT` API exposed by `zstdmt_compress.h` in the shared library, which is now hidden by default. +- The build macro `DYNAMIC_BMI2` can be set to 1 or 0 in order to generate binaries + which can detect at runtime the presence of BMI2 instructions, and use them only if present. + These instructions contribute to better performance, notably on the decoder side. + By default, this feature is automatically enabled on detecting + the right instruction set (x64) and compiler (clang or gcc >= 5). + It's obviously disabled for different cpus, + or when BMI2 instruction set is _required_ by the compiler command line + (in this case, only the BMI2 code path is generated). + Setting this macro will either force to generate the BMI2 dispatcher (1) + or prevent it (0). It overrides automatic detection. + #### Windows : using MinGW+MSYS to create DLL |