clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang++ C++ compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
flang is a Fortran compiler which encompasses parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Flang will stop before doing a full link.
flang is a Fortran compiler which encompasses parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Flang will stop before doing a full link.
clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang++ C++ compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang++ C++ compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
flang is a Fortran compiler which encompasses parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Flang will stop before doing a full link.
clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang++ C++ compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
flang is a Fortran compiler which encompasses parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Flang will stop before doing a full link.
flang is a Fortran compiler which encompasses parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Flang will stop before doing a full link.
clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang++ C++ compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang++ C++ compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
clang is a C compiler which encompasses preprocessing, parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Clang will stop before doing a full link.
flang is a Fortran compiler which encompasses parsing, optimization, code generation, assembly, and linking. Depending on which high-level mode setting is passed, Flang will stop before doing a full link.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This macro indicates that Fortran functions called from C should have their names lower-cased.
The binary datasets for some of the Fortran benchmarks in the SPEC CPU suites are stored in big-endian format. This option is necessary for those datasets to be read in correctly.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option instructs the compiler to treat char type as unsigned.
Some systems need to see alternate definitions for boolean types. This flag enables their use.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
Fortran to C symbol naming. C symbol names are lower case with one underscore. _symbol
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This macro indicates that Fortran functions called from C should have their names lower-cased.
The binary datasets for some of the Fortran benchmarks in the SPEC CPU suites are stored in big-endian format. This option is necessary for those datasets to be read in correctly.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option instructs the compiler to treat char type as unsigned.
Some systems need to see alternate definitions for boolean types. This flag enables their use.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
Fortran to C symbol naming. C symbol names are lower case with one underscore. _symbol
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
This option is used to indicate that the host system's integers are 32-bits wide, and longs and pointers are 64-bits wide. Not all benchmarks recognize this macro, but the preferred practice for data model selection applies the flags to all benchmarks; this flag description is a placeholder for those benchmarks that do not recognize this macro.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
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, the __STDC_IEC_559__ macro is ignored even if set by the system headers.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option enables transformation of the layout of arrays of structure types and their fields to improve the cache locality. Aggressive analysis and transformations are performed at higher levels. This option is effective only with -flto as whole program analysis is required to perform this optimization.
Possible values:
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that transforms the data layout of a single dimensional array to provide better cache locality by analysing the access patterns.
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This option enables the GVN hoist pass, which is used to hoist computations from branches.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option enables an optimization that does the slp vectorization across basic blocks. The SLP vectorizer vectorizes instructions within basic blocks. The global slp vectorizer analyzes instructions across basic blocks and vectorizes them.
This option instructs the compiler to use vector math library.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
Instructs the linker to use the first definition encountered for a symbol, and ignore all others.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
Selects the C++ language dialect.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Disable generation of fma instructions when there is a chain of fma instructions and output of one fma instruction is used as input to other fma instruction.
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
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, the __STDC_IEC_559__ macro is ignored even if set by the system headers.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
Sets the limit at which loops will be unswitched. For example, if unswitch threshold is set to 100 then only loops with 100 or fewer instructions will be unswtched.
This option instructs the compiler to use vector math library.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
This optimization does partial unswitching of loops where some part of the unswitched control flow remains in the loop.
Instructs the linker to use the first definition encountered for a symbol, and ignore all others.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option instructs the compiler to unroll loops wherever possible.
Allocate local variables on the stack, thus allowing recursion. SAVEd, data-initialized, or namelist members are always allocated statically, regardless of the setting of this switch.
This option instructs the compiler to use vector math library.
Instructs the linker to use the first definition encountered for a symbol, and ignore all others.
Instructs the compiler to conform to the IEEE-754 specifications. The compiler will Perform floating-point operations in strict conformance with the IEEE 754 standard. Some optimizations are disabled when this option is specified
Do not allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs. The option instructs the compiler to follow exact implementation of IEEE or ISO rules/specifications for math functions.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
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, the __STDC_IEC_559__ macro is ignored even if set by the system headers.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option enables transformation of the layout of arrays of structure types and their fields to improve the cache locality. Aggressive analysis and transformations are performed at higher levels. This option is effective only with -flto as whole program analysis is required to perform this optimization.
Possible values:
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that transforms the data layout of a single dimensional array to provide better cache locality by analysing the access patterns.
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This option enables the GVN hoist pass, which is used to hoist computations from branches.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option enables an optimization that does the slp vectorization across basic blocks. The SLP vectorizer vectorizes instructions within basic blocks. The global slp vectorizer analyzes instructions across basic blocks and vectorizes them.
This option instructs the compiler to use vector math library.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
This option instructs the compiler to unroll loops wherever possible.
Allocate local variables on the stack, thus allowing recursion. SAVEd, data-initialized, or namelist members are always allocated statically, regardless of the setting of this switch.
Instructs the linker to use the first definition encountered for a symbol, and ignore all others.
Instructs the compiler to conform to the IEEE-754 specifications. The compiler will Perform floating-point operations in strict conformance with the IEEE 754 standard. Some optimizations are disabled when this option is specified
Do not allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs. The option instructs the compiler to follow exact implementation of IEEE or ISO rules/specifications for math functions.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
Selects the C++ language dialect.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Disable generation of fma instructions when there is a chain of fma instructions and output of one fma instruction is used as input to other fma instruction.
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
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, the __STDC_IEC_559__ macro is ignored even if set by the system headers.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option enables transformation of the layout of arrays of structure types and their fields to improve the cache locality. Aggressive analysis and transformations are performed at higher levels. This option is effective only with -flto as whole program analysis is required to perform this optimization.
Possible values:
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that transforms the data layout of a single dimensional array to provide better cache locality by analysing the access patterns.
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This option enables the GVN hoist pass, which is used to hoist computations from branches.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option enables an optimization that does the slp vectorization across basic blocks. The SLP vectorizer vectorizes instructions within basic blocks. The global slp vectorizer analyzes instructions across basic blocks and vectorizes them.
This option instructs the compiler to use vector math library.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
Sets the limit at which loops will be unswitched. For example, if unswitch threshold is set to 100 then only loops with 100 or fewer instructions will be unswtched.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This optimization does partial unswitching of loops where some part of the unswitched control flow remains in the loop.
Instructs the linker to use the first definition encountered for a symbol, and ignore all others.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
Selects the C++ language dialect.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Disable generation of fma instructions when there is a chain of fma instructions and output of one fma instruction is used as input to other fma instruction.
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
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, the __STDC_IEC_559__ macro is ignored even if set by the system headers.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option enables transformation of the layout of arrays of structure types and their fields to improve the cache locality. Aggressive analysis and transformations are performed at higher levels. This option is effective only with -flto as whole program analysis is required to perform this optimization.
Possible values:
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that transforms the data layout of a single dimensional array to provide better cache locality by analysing the access patterns.
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This option enables the GVN hoist pass, which is used to hoist computations from branches.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option enables an optimization that does the slp vectorization across basic blocks. The SLP vectorizer vectorizes instructions within basic blocks. The global slp vectorizer analyzes instructions across basic blocks and vectorizes them.
This option instructs the compiler to use vector math library.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
Sets the limit at which loops will be unswitched. For example, if unswitch threshold is set to 100 then only loops with 100 or fewer instructions will be unswtched.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This optimization does partial unswitching of loops where some part of the unswitched control flow remains in the loop.
This option instructs the compiler to unroll loops wherever possible.
Allocate local variables on the stack, thus allowing recursion. SAVEd, data-initialized, or namelist members are always allocated statically, regardless of the setting of this switch.
Instructs the linker to use the first definition encountered for a symbol, and ignore all others.
Instructs the compiler to conform to the IEEE-754 specifications. The compiler will Perform floating-point operations in strict conformance with the IEEE 754 standard. Some optimizations are disabled when this option is specified
Do not allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs. The option instructs the compiler to follow exact implementation of IEEE or ISO rules/specifications for math functions.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Enables all the optimizations from -O3 along with other aggressive optimizations that may violate strict compliance with language standards. Refer to the AOCC options document for the language you're using for more detailed documentation of optimizations enabled under -Ofast.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option disables the generation of SSE4a instructions.
This option enables transformation of the layout of arrays of structure types and their fields to improve the cache locality. Aggressive analysis and transformations are performed at higher levels. This option is effective only with -flto as whole program analysis is required to perform this optimization.
Possible values:
This option avoids runtime memory dependency checks to enable aggressive vectorization.
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This option enables the GVN hoist pass, which is used to hoist computations from branches.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that transforms the data layout of a single dimensional array to provide better cache locality by analysing the access patterns.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option enables an optimization that does the slp vectorization across basic blocks. The SLP vectorizer vectorizes instructions within basic blocks. The global slp vectorizer analyzes instructions across basic blocks and vectorizes them.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
Selects the C++ language dialect.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Disable generation of fma instructions when there is a chain of fma instructions and output of one fma instruction is used as input to other fma instruction.
Enables all the optimizations from -O3 along with other aggressive optimizations that may violate strict compliance with language standards. Refer to the AOCC options document for the language you're using for more detailed documentation of optimizations enabled under -Ofast.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This optimization does partial unswitching of loops where some part of the unswitched control flow remains in the loop.
Sets the limit at which loops will be unswitched. For example, if unswitch threshold is set to 100 then only loops with 100 or fewer instructions will be unswtched.
This option instructs the compiler to use vector math library.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option instructs the compiler to unroll loops wherever possible.
Allocate local variables on the stack, thus allowing recursion. SAVEd, data-initialized, or namelist members are always allocated statically, regardless of the setting of this switch.
This option instructs the compiler to use vector math library.
Instructs the compiler to conform to the IEEE-754 specifications. The compiler will Perform floating-point operations in strict conformance with the IEEE 754 standard. Some optimizations are disabled when this option is specified
Do not allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs. The option instructs the compiler to follow exact implementation of IEEE or ISO rules/specifications for math functions.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This optimization enables generation of prefetch instructions for tightly coupled loops
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option instructs the compiler to unroll loops wherever possible.
Allocate local variables on the stack, thus allowing recursion. SAVEd, data-initialized, or namelist members are always allocated statically, regardless of the setting of this switch.
This option instructs the compiler to use vector math library.
Instructs the compiler to conform to the IEEE-754 specifications. The compiler will Perform floating-point operations in strict conformance with the IEEE 754 standard. Some optimizations are disabled when this option is specified
Do not allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs. The option instructs the compiler to follow exact implementation of IEEE or ISO rules/specifications for math functions.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
Enables all the optimizations from -O3 along with other aggressive optimizations that may violate strict compliance with language standards. Refer to the AOCC options document for the language you're using for more detailed documentation of optimizations enabled under -Ofast.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option disables the generation of SSE4a instructions.
This option enables transformation of the layout of arrays of structure types and their fields to improve the cache locality. Aggressive analysis and transformations are performed at higher levels. This option is effective only with -flto as whole program analysis is required to perform this optimization.
Possible values:
This option avoids runtime memory dependency checks to enable aggressive vectorization.
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This option enables the GVN hoist pass, which is used to hoist computations from branches.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that transforms the data layout of a single dimensional array to provide better cache locality by analysing the access patterns.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option enables an optimization that does the slp vectorization across basic blocks. The SLP vectorizer vectorizes instructions within basic blocks. The global slp vectorizer analyzes instructions across basic blocks and vectorizes them.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
Like -O2, except that it enables optimizations that take longer to perform or that may generate larger code (in an attempt to make the program run faster).
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
This option instructs the compiler to unroll loops wherever possible.
Allocate local variables on the stack, thus allowing recursion. SAVEd, data-initialized, or namelist members are always allocated statically, regardless of the setting of this switch.
Instructs the compiler to conform to the IEEE-754 specifications. The compiler will Perform floating-point operations in strict conformance with the IEEE 754 standard. Some optimizations are disabled when this option is specified
Do not allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs. The option instructs the compiler to follow exact implementation of IEEE or ISO rules/specifications for math functions.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
Selects the C++ language dialect.
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).
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This flag enables vectorization of loops with complex control flow that can not be vectorized by loop and slp vectorizers.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option causes AOCC to not emit a vzeroupper instruction before a transfer of control flow, in order to minimize the AVX to SSE transition penalty.
Enables all the optimizations from -O3 along with other aggressive optimizations that may violate strict compliance with language standards. Refer to the AOCC options document for the language you're using for more detailed documentation of optimizations enabled under -Ofast.
Specify that Clang should generate code for a specific processor family member and later. For example, if you specify -march=znver1, the compiler is allowed to generate instructions that are valid on AMD Zen processors, but which may not exist on earlier products.
This option disables the generation of SSE4a instructions.
This option enables transformation of the layout of arrays of structure types and their fields to improve the cache locality. Aggressive analysis and transformations are performed at higher levels. This option is effective only with -flto as whole program analysis is required to perform this optimization.
Possible values:
This option avoids runtime memory dependency checks to enable aggressive vectorization.
This option enables an optimization that generates and calls specialized function versions when they are called with constant arguments. This optimization helps in function inlining.
This option enables the GVN hoist pass, which is used to hoist computations from branches.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This option enables an optimization that transforms the data layout of a single dimensional array to provide better cache locality by analysing the access patterns.
This option instructs the compiler to use vector math library.
This option eliminates the array computations based on their usage. The computations on unused array elements and computations on zero valued array elements are eliminated with this optimization. -flto as whole program analysis is required to perform this optimization.
Possible values:
This option enables an optimization that does the slp vectorization across basic blocks. The SLP vectorizer vectorizes instructions within basic blocks. The global slp vectorizer analyzes instructions across basic blocks and vectorizes them.
Sets the compiler's inlining threshold level to the value passed. The inline threshold is used in the inliner heuristics to decide which functions should be inlined.
This option enables an optimization that generates and calls specialized function versions when the loops inside function are vectorizable and the arguments are not aliased with each other. This optimization helps in function inlining and vectorization.
Sets the limit at which loops will be unrolled. For example, if unroll threshold is set to 100 then only loops with 100 or fewer instructions will be unrolled.
This optimization does partial unswitching of loops where some part of the unswitched control flow remains in the loop.
Sets the limit at which loops will be unswitched. For example, if unswitch threshold is set to 100 then only loops with 100 or fewer instructions will be unswtched.
Instructs the compiler to link with system vector math libraries.
Instructs the compiler to link with AMD-supported optimized math library.
Use the jemalloc library, which is a general purpose malloc(3) implementation that emphasizes fragmentation avoidance and scalable concurrency support.
Instructs the compiler to link with flang Fortran runtime libraries.
This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.
Somewhere between -O0 and -O2.
If multiple "O" options are used, with or without level numbers, the last such option is the one that is effective.
Using numactl
to bind processes and memory to cores
For multi-copy runs or single copy runs on systems with multiple sockets, it is advantageous to bind a process to a
particular core. Otherwise, the OS may arbitrarily move your process from one core to another. This can affect
performance. To help, SPEC allows the use of a "submit" command where users can specify a utility to use to bind
processes. We have found the utility 'numactl
' to be the best choice.
numactl
runs processes with a specific NUMA scheduling or memory placement policy. The policy is set for a
command and inherited by all of its children. The numactl
flag "--physcpubind
" specifies
which core(s) to bind the process. "-l
" instructs numactl
to keep a process's memory on the
local node while "-m
" specifies which node(s) to place a process's memory. For full details on using
numactl
, please refer to your Linux documentation, 'man numactl
'
Note that some older versions of numactl
incorrectly interpret application arguments as its own. For
example, with the command "numactl --physcpubind=0 -l a.out -m a
", numactl
will interpret
a.out
's "-m
" option as its own "-m
" option. To work around this problem, we put
the command to be run in a shell script and then run the shell script using numactl
. For example:
"echo 'a.out -m a' > run.sh ; numactl --physcpubind=0 bash run.sh
"
Transparent Huge Pages (THP)
THP is an abstraction layer that automates most aspects of creating, managing, and using huge pages. THP is designed to hide much of the complexity in using huge pages from system administrators and developers, as normal huge pages must be assigned at boot time, can be difficult to manage manually, and often require significant changes to code in order to be used effectively. Most recent Linux OS releases have THP enabled by default.
Linux Huge Page settings
If you need finer control you can manually set huge pages using the following steps:
mkdir /mnt/hugepages
mount -t hugetlbfs nodev /mnt/hugepages
vm/nr_hugepages=N
in /etc/sysctl.conf
where N is the maximum number of pages the
system may allocate.Note that further information about huge pages may be found in the Linux kernel documentation file
hugetlbpage.txt
.
ulimit -s <n>
Sets the stack size to n kbytes, or unlimited to allow the stack size to grow without limit.
ulimit -l <n>
Sets the maximum size of memory that may be locked into physical memory.
powersave -f
(on SuSE)
Makes the powersave daemon set the CPUs to the highest supported frequency.
/etc/init.d/cpuspeed stop
(on Red Hat)
Disables the cpu frequency scaling program in order to set the CPUs to the highest supported frequency.
LD_LIBRARY_PATH
An environment variable that indicates the location in the filesystem of bundled libraries to use when running the benchmark binaries.
kernel/randomize_va_space
This option can be used to select the type of process address space randomization that is used in the system, for architectures that support this feature.
norandmaps
" parameter.CONFIG_COMPAT_BRK
option is enabled.CONFIG_COMPAT_BRK
is
disabled.MALLOC_CONF
An environment variable set to tune the jemalloc allocation strategy during the execution of the binaries. This environment variable setting is not needed when building the binaries on the system under test.
Model | Minimum cTDP | Maximum cTDP |
---|---|---|
EPYC 7742 | 225 | 240 |
EPYC 7702 | 165 | 200 |
EPYC 7702P | 180 | 200 |
EPYC 7452 | 155 | 180 |
EPYC 7H12 | 225 | 280 |
EPYC 7762 | 225 | 240 |
EPYC 7642 | 225 | 240 |
EPYC 7552 | 165 | 200 |
EPYC 7542 | 225 | 240 |
EPYC 7532 | 165 | 200 |
EPYC 7502 | 165 | 200 |
EPYC 7502P | 165 | 200 |
EPYC 7402 | 165 | 200 |
EPYC 7402P | 165 | 200 |
EPYC 7352 | 155 | 180 |
EPYC 7302 | 155 | 180 |
EPYC 7302P | 155 | 180 |
EPYC 7282 | 120 | 150 |
EPYC 7272 | 120 | 150 |
EPYC 7262 | 155 | 180 |
EPYC 7252 | 120 | 150 |
EPYC 7232P | 120 | 150 |
Flag description origin markings:
For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact info@spec.org
Copyright 2017-2019 Standard Performance Evaluation Corporation
Tested with SPEC CPU2017 v1.1.0.
Report generated on 2019-11-12 15:00:49 by SPEC CPU2017 flags formatter v5178.