MPI2007 Flag Description
Lenovo Global Technology ThinkSystem SR665 (AMD EPYC 7H12, 2.6 GHz)

Base Optimization Flags

C benchmarks

• • -Ofast
  • 
  • COPTIMIZE

  • Ofast enables all -O3 optimizations. It also enables optimizations that are not valid for all standard-compliant programs.

• • -flto
  • 
  • COPTIMIZE

  • Generate output files in LLVM formats, suitable for link time optimization. When used with -S this generates LLVM intermediate language assembly files, otherwise this generates LLVM bitcode format object files (which may be passed to the linker depending on the stage selection options).

• • -ffast-math
  • 
  • COPTIMIZE

  • Enables a range of optimizations that provide faster, though sometimes less precise, mathematical operations that may not conform to the IEEE-754 specifications. When this option is specified, __STDC_IEC_559__ macro is ignored even if set by the system headers

• • -march=znver2
  • 
  • COPTIMIZE

  • Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver2, the compiler is allowed to generate instructions that are valid on AMD Zen2 processors, but which may not exist on earlier products.

• • -mavx2
  • 
  • COPTIMIZE

  • Generate code for processors that include the AVX2 extensions.

• • -L/home/AMD_libm/amd-libm/lib
  • 
  • EXTRA_LIBS

  • Specify AMD libm path.

• • -lamdlibm
  • 
  • EXTRA_LIBS

  • AMD LibM is a software library containing a collection of basic math functions optimized for x86-64 processor-based machines. It provides many routines from the list of standard C99 math functions. Applications can link into AMD LibM library and invoke math functions instead of compiler's math functions for better accuracy and performance.

C++ benchmarks

126.lammps

• • -Ofast
  • 
  • CXXOPTIMIZE

  • Ofast enables all -O3 optimizations. It also enables optimizations that are not valid for all standard-compliant programs.

• • -flto
  • 
  • CXXOPTIMIZE

  • Generate output files in LLVM formats, suitable for link time optimization. When used with -S this generates LLVM intermediate language assembly files, otherwise this generates LLVM bitcode format object files (which may be passed to the linker depending on the stage selection options).

• • -ffast-math
  • 
  • CXXOPTIMIZE

  • Enables a range of optimizations that provide faster, though sometimes less precise, mathematical operations that may not conform to the IEEE-754 specifications. When this option is specified, __STDC_IEC_559__ macro is ignored even if set by the system headers

• • -march=znver2
  • 
  • CXXOPTIMIZE

  • Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver2, the compiler is allowed to generate instructions that are valid on AMD Zen2 processors, but which may not exist on earlier products.

• • -mavx2
  • 
  • CXXOPTIMIZE

  • Generate code for processors that include the AVX2 extensions.

• • -L/home/AMD_libm/amd-libm/lib
  • 
  • EXTRA_LIBS

  • Specify AMD libm path.

• • -lamdlibm
  • 
  • EXTRA_LIBS

  • AMD LibM is a software library containing a collection of basic math functions optimized for x86-64 processor-based machines. It provides many routines from the list of standard C99 math functions. Applications can link into AMD LibM library and invoke math functions instead of compiler's math functions for better accuracy and performance.

Fortran benchmarks

• • -Ofast
  • 
  • FOPTIMIZE

  • Ofast enables all -O3 optimizations. It also enables optimizations that are not valid for all standard-compliant programs.

• • -flto
  • 
  • FOPTIMIZE

  • Generate output files in LLVM formats, suitable for link time optimization. When used with -S this generates LLVM intermediate language assembly files, otherwise this generates LLVM bitcode format object files (which may be passed to the linker depending on the stage selection options).

• • -ffast-math
  • 
  • FOPTIMIZE

  • Enables a range of optimizations that provide faster, though sometimes less precise, mathematical operations that may not conform to the IEEE-754 specifications. When this option is specified, __STDC_IEC_559__ macro is ignored even if set by the system headers

• • -march=znver2
  • 
  • FOPTIMIZE

  • Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver2, the compiler is allowed to generate instructions that are valid on AMD Zen2 processors, but which may not exist on earlier products.

• • -funroll-loops
  • 
  • FOPTIMIZE

  • Instructs the compiler to unroll the loops wherever possible.

• • -mavx2
  • 
  • FOPTIMIZE

  • Generate code for processors that include the AVX2 extensions.

• • -L/home/AMD_libm/amd-libm/lib
  • 
  • EXTRA_FLIBS, EXTRA_LIBS

  • Specify AMD libm path.

• • -lamdlibm
  • 
  • EXTRA_FLIBS, EXTRA_LIBS

  • AMD LibM is a software library containing a collection of basic math functions optimized for x86-64 processor-based machines. It provides many routines from the list of standard C99 math functions. Applications can link into AMD LibM library and invoke math functions instead of compiler's math functions for better accuracy and performance.

Benchmarks using both Fortran and C

• • -Ofast
  • 
  • COPTIMIZE, FOPTIMIZE

  • Ofast enables all -O3 optimizations. It also enables optimizations that are not valid for all standard-compliant programs.

• • -flto
  • 
  • COPTIMIZE, FOPTIMIZE

  • Generate output files in LLVM formats, suitable for link time optimization. When used with -S this generates LLVM intermediate language assembly files, otherwise this generates LLVM bitcode format object files (which may be passed to the linker depending on the stage selection options).

• • -ffast-math
  • 
  • COPTIMIZE, FOPTIMIZE

  • Enables a range of optimizations that provide faster, though sometimes less precise, mathematical operations that may not conform to the IEEE-754 specifications. When this option is specified, __STDC_IEC_559__ macro is ignored even if set by the system headers

• • -march=znver2
  • 
  • COPTIMIZE, FOPTIMIZE

  • Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver2, the compiler is allowed to generate instructions that are valid on AMD Zen2 processors, but which may not exist on earlier products.

• • -mavx2
  • 
  • COPTIMIZE, FOPTIMIZE

  • Generate code for processors that include the AVX2 extensions.

• • -funroll-loops
  • 
  • FOPTIMIZE

  • Instructs the compiler to unroll the loops wherever possible.

• • -L/home/AMD_libm/amd-libm/lib
  • 
  • EXTRA_FLIBS, EXTRA_LIBS

  • Specify AMD libm path.

• • -lamdlibm
  • 
  • EXTRA_FLIBS, EXTRA_LIBS

  • AMD LibM is a software library containing a collection of basic math functions optimized for x86-64 processor-based machines. It provides many routines from the list of standard C99 math functions. Applications can link into AMD LibM library and invoke math functions instead of compiler's math functions for better accuracy and performance.