This code accompanies the article "Lomuto's Comeback" in The D Blog.
To build the benchmarks, use for gdc:
# std::sort baseline
gdc -O3 -frelease -fno-assert -fbounds-check=off -fno-postconditions -fno-preconditions -fversion=STDSORT lomuto.d
# Use Hoare partition
gdc -O3 -frelease -fno-assert -fbounds-check=off -fno-postconditions -fno-preconditions lomuto.d
# Use Lomuto partition, traditional implementation
gdc -O3 -frelease -fno-assert -fbounds-check=off -fno-postconditions -fno-preconditions -fversion=LOMUTO_BRANCHY lomuto.d
# Use Lomuto partition, branch-free implementation
gdc -O3 -frelease -fno-assert -fbounds-check=off -fno-postconditions -fno-preconditions -fversion=LOMUTO lomuto.d
For ldc:
# std::sort baseline
ldc 1.17.0 -O3 -boundscheck=off -release -d-version=STDSORT lomuto.d
# Use Hoare partition
ldc 1.17.0 -O3 -boundscheck=off -release lomuto.d
# Use Lomuto partition, traditional implementation
ldc 1.17.0 -O3 -boundscheck=off -release -d-version=LOMUTO_BRANCHY lomuto.d
# Use Lomuto partition, branch-free implementation
ldc 1.17.0 -O3 -boundscheck=off -release -d-version=LOMUTO lomuto.d
For gcc:
# std::sort baseline
g++ -std=c++17 -O3 -DNDEBUG -DSTDSORT lomuto.cpp
# Use Hoare partition
g++ -std=c++17 -O3 -DNDEBUG lomuto.cpp
# Use Lomuto partition, traditional implementation
g++ -std=c++17 -O3 -DNDEBUG -DLOMUTO_BRANCHY lomuto.cpp
# Use Lomuto partition, branch-free implementation
g++ -std=c++17 -O3 -DNDEBUG -DLOMUTO lomuto.cpp
For clang:
# std::sort baseline
clang++ -std=c++17 -O3 -DNDEBUG -DSTDSORT lomuto.cpp
# Use Hoare partition
clang++ -std=c++17 -O3 -DNDEBUG lomuto.cpp
# Use Lomuto partition, traditional implementation
clang++ -std=c++17 -O3 -DNDEBUG -DLOMUTO_BRANCHY lomuto.cpp
# Use Lomuto partition, branch-free implementation
clang++ -std=c++17 -O3 -DNDEBUG -DLOMUTO lomuto.cpp
Run the produced binary with one numeric argument, the number of items to sort. Beware: all compilers write to ./a.out except for ldc, which writes to ./lomuto.