Skip to content
glaucus

zstd

Prepare

Section titled “Prepare”
  • The notrace patch is only for gcc 10, and is not needed with gcc 11+ as LTO works with zstd

Build

Section titled “Build”
  • zstd was benchmarked with zstd -b3 -e9 -i3 $file
  • gcc’s -O3 regresses both in size and performance (up to 50% performance loss)
  • -Os also results in performance regressions
  • -O2 produces the best results for both clang and gcc
  • LDFLAGS can be passed using LDFLAGS_DYNLIB="$LDFLAGS" make not make LDFLAGS_DYNLIB="$LDFLAGS" as the latter removes -pthread
  • make -C lib libzstd only builds the dynamic library
  • make lib-mt force enables multithreading on both dynamic and (the removed) static libraries and it is not needed
  • The dynamic library is multithreaded and the static library is single-threaded by default
  • make -C programs zstd-dll builds zstd as a thin wrapper around the dynamic libzstd.so library that was just built
  • make -C programs zstd-dll target produces a much smaller zstd compared to make zstd
  • HASH=xxhsum uses the faster xxhash instead of the default md5sum but introduces a build-time only dependency on xxhash
  • HAVE_ZLIB, HAVE_LZMA and HAVE_LZ4 are only relevant for programs and are enabled if detected so disable them explicitly
  • ZSTD_LIB_MINIFY=1 overrides CFLAGS with -Oz if CC is set to clang which results in performance regressions
  • ZSTD_NO_ASM=0 is set by default
  • ZSTD_NOBENCH, ZSTD_NODICT and ZSTD_NOTRACE are preprocessor macros that shouldn’t be passed as make variables
  • Do not override CFLAGS to pass preprocessor macros, instead use CPPFLAGS
  • Do not override CFLAGS for lib with make -C lib CFLAGS="$CFLAGS" as it removes -fPIC and other default flags including warnings

Package

Section titled “Package”
  • Do not use the make install target as it builds and installs the static library as well
  • PKGCONFIGDIR controls where the .pc file is installed (not PCLIBDIR)
  • -pthread is included in libzstd.pc and is automatically passed when linking against it

Other

Section titled “Other”
  • make is the official build system (other build systems, though compatible, are maintained by 3rd-parties)
  • Level 3 is good enough; after level 19 it will regress
  • Prefer zstd -T0 to zstdmt and pzstd as it is more modern
  • Static library can be disabled with cmake
  • Support for decoding legacy formats will be disabled by default (ZSTD_LEGACY_SUPPORT=0) from 1.6.0
  • zstd is multithreaded, faster and more widely adopted compared to brotli

Old

Section titled “Old”
  • clear’s fopen patch has an m mode (rbm) that is only for glibc

References

Section titled “References”