The PGI C compiler.
The PGI C++ compiler.
The PGI Fortran 95 compiler.
Invoke the PathScale C compiler.
Also used to invoke linker for C programs.
The PGI C compiler.
Invoke the PathScale C++ compiler.
Also used to invoke linker for C++ programs.
The PGI C++ compiler.
The PGI C++ compiler.
Invoke the PathScale Fortran 77, 90 and 95 compilers.
Also used to invoke linker for Fortran programs and
for mixed C / Fortran. pathf90 and pathf95 are synonymous.
The PGI Fortran 95 compiler.
The PGI Fortran 95 compiler.
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.
Don't include Fortran main program object module.
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.
Don't include Fortran main program object module.
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.
Don't include Fortran main program object module.
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.
This macro indicates that the benchmark is being compiled on a Linux system.
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.
Don't include Fortran main program object module.
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.
CFP2006:
If -funderscoring is in effect, and the original Fortran external identifier contained an underscore, -fsecond-underscore appends a second underscore to the one added by -funderscoring. -fno-second-underscore does not append a second underscore. The default is both -funderscoring and -fsecond-underscore, the same defaults as g77 uses. -fno-second-underscore corresponds to the default policies of PGI Fortran and Intel Fortran.
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.
Don't include Fortran main program object module.
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.
This macro indicates that the benchmark is being compiled on a Linux system.
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.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Generate zero-overhead C++ exception handlers.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Generate profile-feedback instrumentation (PFI); this includes extra code to collect run-time statistics and dump them to a trace file for use in a subsequent compilation. PFI gathers information about a program's execution and data values but does not gather information from hardware performance counters. PFI does gather data for optimizations which are unique to profile-feedback optimization.
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
Interprocedural Analysis option: Do not remove arguments replaced by -Mipa=ptr,const
Enable profile-feedback optimizations.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Enable dead store elimination.
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Equivalent to -O3 -ipa -OPT:Ofast -fno-math-errno -ffast-math.
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
NOTE: -Ofast enables -ipa (inter-procedural analysis), which places limitations on how libraries and .o files are built.
-fb_create <path>
Used to specify that an instrumented executable program is to be
generated. Such an executable is suitable for producing feedback
data files with the specified prefix for use in feedback-directed
optimization (FDO).
The commonly used prefix is "fbdata".
This is OFF by default.
During the training run, the instrumented executable produces information regarding execution paths and data values, but does not generate information by using hardware performance counters.
-fb_opt <prefix for feedback data files>
Used to specify feedback-directed optimization (FDO) by extracting
feedback data from files with the specified prefix, which were
previously generated using -fb-create.
The commonly used prefix is "fbdata".
The same optimization flags should be used
for both the -fb-create and fb_opt compile steps.
Feedback data files created from executables compiled
with different optimization flags may give checksum errors.
FDO is OFF by default.
During the -fb_opt compilation phase, information regarding execution paths and data values are used to improve the information available to the optimizer. FDO enables some optimizations which are only performed when the feedback data file is available. The safety of optimizations performed under FDO is consistent with the level of safety implied by the other optimization flags (outside of fb_create and fb_opt) specified on the compile and link lines.
Specify the basic level of optimization desired.
The options can be one of the following:
0 Turn off all optimizations.
1 Turn on local optimizations that can be done quickly. Do peephole optimizations and instruction scheduling.
2 Turn on extensive optimization.
This is the default.
The optimizations at this level are generally conservative,
in the sense that they are virtually always beneficial and
avoid changes which affect
such things as floating point accuracy. In addition to the level
1 optimizations, do inner loop
unrolling, if-conversion, two passes of instruction scheduling,
global register allocation, dead store elimination,
instruction scheduling across basic blocks,
and partial redundancy elimination.
3 Turn on aggressive optimization.
The optimizations at this level are distinguished from -O2
by their aggressiveness, generally seeking highest-quality
generated code even if it requires extensive compile time.
They may include optimizations that are generally beneficial
but may hurt performance.
This includes but is not limited to turning on the
Loop Nest Optimizer, -LNO:opt=1, and setting
-OPT:roundoff=1:IEEE_arithmetic=2:Olimit=9000:reorg_common=ON.
s Specify that code size is to be given priority in tradeoffs with execution time.
If no value is specified, 2 is assumed.-OPT:Ofast
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
This effectively turns on the following optimizations:
-OPT:ro=2:Olimit=0:div_split=ON:alias=typed.
The -WOPT: Specifies options that affect the global optimizer. The options are enabled at -O2 or above.
-WOPT:aggstr=N
This controls the aggressiveness of the strength reduction optimization
performed by the scalar optimizer, in which induction expressions
within a loop are replaced by temporaries that are incremented
together with the loop variable. When strength reduction is overdone,
the additional temporaries increase register pressure, resulting in
excessive register spills that decrease performance.
The value specified must be a positive integer value, which specifies
the maximum number of induction expressions that will be strength-reduced
across an index variable increment.
When set at 0, strength reduction is only performed for non-trivial
induction expressions. The default is 11.
Compile for 32-bit ABI, also known as x86 or IA32.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Generate zero-overhead C++ exception handlers.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Don't check dependence relations for vector or parallel code.
Enable generation of prefetch instructions on processors where they are supported.
Allow parallelization of loops with conditional scalar assignments.
Instructs the compiler that static pointers and arrays do not overlap or conflict with each other and are independent.
Generate code to check for zero loop increments.
"-Munroll=n:n" instructs the compiler to unroll loops n times where n is a supplied constant value. If no constant value is given, then a default of 4 is used.
Instructs the vectorizer to disable idiom recognition.
Instructs the vectorizer to generate prefetch instructions.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Equivalent to -O3 -ipa -OPT:Ofast -fno-math-errno -ffast-math.
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
NOTE: -Ofast enables -ipa (inter-procedural analysis), which places limitations on how libraries and .o files are built.
-INLINE:aggressive : Tell the compiler to be more aggressive about inlining. The default is -INLINE:aggressive=OFF.
-OPT:malloc_alg=(0|1)
Select an alternate malloc algorithm which may improve speed.
The compiler adds setup code in the
C/C++/Fortran "main" function to enable the chosen algorithm.
The default is 0.
Compile for 32-bit ABI, also known as x86 or IA32.
(For C++ only) -fexceptions enables exception handling. This is the default. -fno-exceptions disables exception handling.
-fb_create <path>
Used to specify that an instrumented executable program is to be
generated. Such an executable is suitable for producing feedback
data files with the specified prefix for use in feedback-directed
optimization (FDO).
The commonly used prefix is "fbdata".
This is OFF by default.
During the training run, the instrumented executable produces information regarding execution paths and data values, but does not generate information by using hardware performance counters.
-fb_opt <prefix for feedback data files>
Used to specify feedback-directed optimization (FDO) by extracting
feedback data from files with the specified prefix, which were
previously generated using -fb-create.
The commonly used prefix is "fbdata".
The same optimization flags should be used
for both the -fb-create and fb_opt compile steps.
Feedback data files created from executables compiled
with different optimization flags may give checksum errors.
FDO is OFF by default.
During the -fb_opt compilation phase, information regarding execution paths and data values are used to improve the information available to the optimizer. FDO enables some optimizations which are only performed when the feedback data file is available. The safety of optimizations performed under FDO is consistent with the level of safety implied by the other optimization flags (outside of fb_create and fb_opt) specified on the compile and link lines.
Compile for 32-bit ABI, also known as x86 or IA32.
Specify the basic level of optimization desired.
The options can be one of the following:
0 Turn off all optimizations.
1 Turn on local optimizations that can be done quickly. Do peephole optimizations and instruction scheduling.
2 Turn on extensive optimization.
This is the default.
The optimizations at this level are generally conservative,
in the sense that they are virtually always beneficial and
avoid changes which affect
such things as floating point accuracy. In addition to the level
1 optimizations, do inner loop
unrolling, if-conversion, two passes of instruction scheduling,
global register allocation, dead store elimination,
instruction scheduling across basic blocks,
and partial redundancy elimination.
3 Turn on aggressive optimization.
The optimizations at this level are distinguished from -O2
by their aggressiveness, generally seeking highest-quality
generated code even if it requires extensive compile time.
They may include optimizations that are generally beneficial
but may hurt performance.
This includes but is not limited to turning on the
Loop Nest Optimizer, -LNO:opt=1, and setting
-OPT:roundoff=1:IEEE_arithmetic=2:Olimit=9000:reorg_common=ON.
s Specify that code size is to be given priority in tradeoffs with execution time.
If no value is specified, 2 is assumed.-OPT:IEEE_arithmetic,IEEE_arith,IEEE_a=(1|2|3)
Specify the level of conformance to IEEE 754 floating pointing
roundoff/overflow behavior.
The options can be one of the following:
1 Adhere to IEEE accuracy. This is the default when optimization levels -O0, -O1 and -O2 are in effect.
2 May produce inexact result not conforming to IEEE 754. This is the default when -O3 is in effect.
3 All mathematically valid transformations are allowed.
-CG:load_exe=N : Specify the threshold for subsuming a memory load
operation into the operand of an arithmetic instruction.
The value of 0 turns off this subsumption optimization.
If N is 1, this subsumption is performed only when the result of
the load has only one use.
This subsumption is not performed if the number of times the result
of the load is used exceeds the value N, a non-negative integer.
If the ABI is 64-bit and the language is Fortran, the default for N
is 2, otherwise the default is 1.
-CG:movnti=N : Convert ordinary stores to non-temporal stores when writing memory blocks of size larger than N KB. When N is set to 0, this transformation is avoided. The default value is 120 (KB).
Enable or disable moving loop-invariant expressions out of loops. The default is ON.
-LNO:prefetch=(0|1|2|3) : This option specifies the level of prefetching.
0 = Prefetch disabled.
1 = Prefetch is done only for arrays that are always referenced in each iteration of a loop.
2 = Prefetch is done without the above restriction. This is the default.
3 = Most aggressive.
(For C++ only) -fexceptions enables exception handling. This is the default. -fno-exceptions disables exception handling.
-fb_create <path>
Used to specify that an instrumented executable program is to be
generated. Such an executable is suitable for producing feedback
data files with the specified prefix for use in feedback-directed
optimization (FDO).
The commonly used prefix is "fbdata".
This is OFF by default.
During the training run, the instrumented executable produces information regarding execution paths and data values, but does not generate information by using hardware performance counters.
-fb_opt <prefix for feedback data files>
Used to specify feedback-directed optimization (FDO) by extracting
feedback data from files with the specified prefix, which were
previously generated using -fb-create.
The commonly used prefix is "fbdata".
The same optimization flags should be used
for both the -fb-create and fb_opt compile steps.
Feedback data files created from executables compiled
with different optimization flags may give checksum errors.
FDO is OFF by default.
During the -fb_opt compilation phase, information regarding execution paths and data values are used to improve the information available to the optimizer. FDO enables some optimizations which are only performed when the feedback data file is available. The safety of optimizations performed under FDO is consistent with the level of safety implied by the other optimization flags (outside of fb_create and fb_opt) specified on the compile and link lines.
Specify the basic level of optimization desired.
The options can be one of the following:
0 Turn off all optimizations.
1 Turn on local optimizations that can be done quickly. Do peephole optimizations and instruction scheduling.
2 Turn on extensive optimization.
This is the default.
The optimizations at this level are generally conservative,
in the sense that they are virtually always beneficial and
avoid changes which affect
such things as floating point accuracy. In addition to the level
1 optimizations, do inner loop
unrolling, if-conversion, two passes of instruction scheduling,
global register allocation, dead store elimination,
instruction scheduling across basic blocks,
and partial redundancy elimination.
3 Turn on aggressive optimization.
The optimizations at this level are distinguished from -O2
by their aggressiveness, generally seeking highest-quality
generated code even if it requires extensive compile time.
They may include optimizations that are generally beneficial
but may hurt performance.
This includes but is not limited to turning on the
Loop Nest Optimizer, -LNO:opt=1, and setting
-OPT:roundoff=1:IEEE_arithmetic=2:Olimit=9000:reorg_common=ON.
s Specify that code size is to be given priority in tradeoffs with execution time.
If no value is specified, 2 is assumed.-OPT:Ofast
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
This effectively turns on the following optimizations:
-OPT:ro=2:Olimit=0:div_split=ON:alias=typed.
-OPT:IEEE_arithmetic,IEEE_arith,IEEE_a=(1|2|3)
Specify the level of conformance to IEEE 754 floating pointing
roundoff/overflow behavior.
The options can be one of the following:
1 Adhere to IEEE accuracy. This is the default when optimization levels -O0, -O1 and -O2 are in effect.
2 May produce inexact result not conforming to IEEE 754. This is the default when -O3 is in effect.
3 All mathematically valid transformations are allowed.
Specify options and transformations performed on loop nests by the Loop Nest Optimizer (LNO). The -LNO options are enabled only if -O3 is also specified on the pathf95 command line.
-LNO:blocking : Enable or disable the cache blocking transformation. The default is ON.
-LNO:ignore_feedback=(on|off|0|1) : If the flag is ON then feedback information from the loop annotations will be ignored in LNO transformations. The default is OFF.
-fb_create <path>
Used to specify that an instrumented executable program is to be
generated. Such an executable is suitable for producing feedback
data files with the specified prefix for use in feedback-directed
optimization (FDO).
The commonly used prefix is "fbdata".
This is OFF by default.
During the training run, the instrumented executable produces information regarding execution paths and data values, but does not generate information by using hardware performance counters.
-fb_opt <prefix for feedback data files>
Used to specify feedback-directed optimization (FDO) by extracting
feedback data from files with the specified prefix, which were
previously generated using -fb-create.
The commonly used prefix is "fbdata".
The same optimization flags should be used
for both the -fb-create and fb_opt compile steps.
Feedback data files created from executables compiled
with different optimization flags may give checksum errors.
FDO is OFF by default.
During the -fb_opt compilation phase, information regarding execution paths and data values are used to improve the information available to the optimizer. FDO enables some optimizations which are only performed when the feedback data file is available. The safety of optimizations performed under FDO is consistent with the level of safety implied by the other optimization flags (outside of fb_create and fb_opt) specified on the compile and link lines.
Specify the basic level of optimization desired.
The options can be one of the following:
0 Turn off all optimizations.
1 Turn on local optimizations that can be done quickly. Do peephole optimizations and instruction scheduling.
2 Turn on extensive optimization.
This is the default.
The optimizations at this level are generally conservative,
in the sense that they are virtually always beneficial and
avoid changes which affect
such things as floating point accuracy. In addition to the level
1 optimizations, do inner loop
unrolling, if-conversion, two passes of instruction scheduling,
global register allocation, dead store elimination,
instruction scheduling across basic blocks,
and partial redundancy elimination.
3 Turn on aggressive optimization.
The optimizations at this level are distinguished from -O2
by their aggressiveness, generally seeking highest-quality
generated code even if it requires extensive compile time.
They may include optimizations that are generally beneficial
but may hurt performance.
This includes but is not limited to turning on the
Loop Nest Optimizer, -LNO:opt=1, and setting
-OPT:roundoff=1:IEEE_arithmetic=2:Olimit=9000:reorg_common=ON.
s Specify that code size is to be given priority in tradeoffs with execution time.
If no value is specified, 2 is assumed.-OPT:Ofast
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
This effectively turns on the following optimizations:
-OPT:ro=2:Olimit=0:div_split=ON:alias=typed.
-OPT:roundoff,ro=(0|1|2|3)
Specify the level of acceptable departure from source language
floating-point, round-off, and overflow semantics.
The options can be one of the following:
0 = Inhibit optimizations that might affect the floating-point behavior. This is the default when optimization levels -O0, -O1, and -O2 are in effect.
1 = Allow simple transformations that might cause limited round-off or overflow differences. Compounding such transformations could have more extensive effects. This is the default when -O3 is in effect.
2 = Allow more extensive transformations, such as the reordering of reduction loops. This is the default level when -OPT:Ofast is specified.
3 = Enable any mathematically valid transformation.
-OPT:unroll_size=N
Set the ceiling of maximum number of instructions for an
unrolled inner loop. If N=0, the ceiling is disregarded.
The default is 40.
Equivalent to -O3 -ipa -OPT:Ofast -fno-math-errno -ffast-math.
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
NOTE: -Ofast enables -ipa (inter-procedural analysis), which places limitations on how libraries and .o files are built.
-OPT:malloc_alg=(0|1)
Select an alternate malloc algorithm which may improve speed.
The compiler adds setup code in the
C/C++/Fortran "main" function to enable the chosen algorithm.
The default is 0.
Equivalent to -O3 -ipa -OPT:Ofast -fno-math-errno -ffast-math.
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
NOTE: -Ofast enables -ipa (inter-procedural analysis), which places limitations on how libraries and .o files are built.
-LNO:fission=N : Perform loop fission. N can be one of the following:
0 = Disable loop fission (default)
1 = Perform normal loop fission as necessary
2 = Specify that fission be tried before fusion
Because -LNO:fusion is on by default, turning on fission without turning off fusion may result in their effects being nullified. Ordinarily, fusion is applied before fission. Specifying -LNO:fission=2 will turn on fission and cause it to be applied before fusion.
-LNO:prefetch=(0|1|2|3) : This option specifies the level of prefetching.
0 = Prefetch disabled.
1 = Prefetch is done only for arrays that are always referenced in each iteration of a loop.
2 = Prefetch is done without the above restriction. This is the default.
3 = Most aggressive.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
Disables alternate code generation for vectorized loops.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to use low-precision approximation in the calculation of reciprocal square root (1/sqrt). Can result in improved performance at the expense of numerical accuracy.
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
-fb_create <path>
Used to specify that an instrumented executable program is to be
generated. Such an executable is suitable for producing feedback
data files with the specified prefix for use in feedback-directed
optimization (FDO).
The commonly used prefix is "fbdata".
This is OFF by default.
During the training run, the instrumented executable produces information regarding execution paths and data values, but does not generate information by using hardware performance counters.
-fb_opt <prefix for feedback data files>
Used to specify feedback-directed optimization (FDO) by extracting
feedback data from files with the specified prefix, which were
previously generated using -fb-create.
The commonly used prefix is "fbdata".
The same optimization flags should be used
for both the -fb-create and fb_opt compile steps.
Feedback data files created from executables compiled
with different optimization flags may give checksum errors.
FDO is OFF by default.
During the -fb_opt compilation phase, information regarding execution paths and data values are used to improve the information available to the optimizer. FDO enables some optimizations which are only performed when the feedback data file is available. The safety of optimizations performed under FDO is consistent with the level of safety implied by the other optimization flags (outside of fb_create and fb_opt) specified on the compile and link lines.
Specify the basic level of optimization desired.
The options can be one of the following:
0 Turn off all optimizations.
1 Turn on local optimizations that can be done quickly. Do peephole optimizations and instruction scheduling.
2 Turn on extensive optimization.
This is the default.
The optimizations at this level are generally conservative,
in the sense that they are virtually always beneficial and
avoid changes which affect
such things as floating point accuracy. In addition to the level
1 optimizations, do inner loop
unrolling, if-conversion, two passes of instruction scheduling,
global register allocation, dead store elimination,
instruction scheduling across basic blocks,
and partial redundancy elimination.
3 Turn on aggressive optimization.
The optimizations at this level are distinguished from -O2
by their aggressiveness, generally seeking highest-quality
generated code even if it requires extensive compile time.
They may include optimizations that are generally beneficial
but may hurt performance.
This includes but is not limited to turning on the
Loop Nest Optimizer, -LNO:opt=1, and setting
-OPT:roundoff=1:IEEE_arithmetic=2:Olimit=9000:reorg_common=ON.
s Specify that code size is to be given priority in tradeoffs with execution time.
If no value is specified, 2 is assumed.-LNO:prefetch=(0|1|2|3) : This option specifies the level of prefetching.
0 = Prefetch disabled.
1 = Prefetch is done only for arrays that are always referenced in each iteration of a loop.
2 = Prefetch is done without the above restriction. This is the default.
3 = Most aggressive.
-LNO:prefetch_ahead=N : Prefetch N cache line(s) ahead. The default is 2.
-LNO:ou_prod_max=N : This option indicates that the product of unrolling of the various outer loops in a given loop nest is not to exceed N, where N is a positive integer. The default is 16.
-LNO:full_unroll,fu=N : Fully unroll loops with trip_count <= N inside LNO. N can be any integer between 0 and 100. The default value for N is 5. Setting this flag to 0 disables full unrolling of small trip count loops inside LNO.
Invoke inter-procedural analysis (IPA). Specifying this option is identical to specifying -IPA or -IPA:. Default settings for the individual IPA suboptions are used.
Chooses generally optimal flags for the target platform. As of the PGI 7.0 release, the flags "-fast" and "-fastsse" are equivlent for 64-bit compilations. For 32-bit compilations "-fast" does not include "-Mscalasse", "-Mcache_align", or "-Mvect=sse".
Instructs the compiler to use relaxed precision in the calculation of some intrinsic functions. Can result in improved performance at the expense of numerical accuracy. The default on an AMD system is "-Mfprelaxed=rsqrt,order". The default on an Intel system is "-Mfprelaxed=rsqrt,sqrt,div,order"
Link with the huge page runtime library and allocate a maximum n huge pages.
Disables alternate code generation for vectorized loops.
Specify the type of the target processor as AMD64 Barcelona Processor 64-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
Disable warning messages.
Disable warning messages.
Disable warning messages.
Disable warning messages.
Disable warning messages.
Disable warning messages.
-static: On systems that support dynamic linking, this prevents linking with the shared libraries. On other systems, this option has no effect.
Disable warning messages.
Disable warning messages.
Disable warning messages.
This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.
Level-two optimization (-O2 or -O) specifies global optimization. The -fast option generally will specify global optimization; however, the -fast switch will vary from release to release depending on a reasonable selection of switches for any one particular release. The -O or -O2 level performs all level-one local optimizations as well as global optimizations. Control flow analysis is applied and global registers are allocated for all functions and subroutines. Loop regions are given special consideration. This optimization level is a good choice when the program contains loops, the loops are short, and the structure of the code is regular.
The PGI compilers perform many different types of global optimizations, including but not limited to:
Level-one optimization specifies local optimization (-O1). The compiler performs scheduling of basic blocks as well as register allocation. This optimization level is a good choice when the code is very irregular; that is it contains many short statements containing IF statements and the program does not contain loops (DO or DO WHILE statements). For certain types of code, this optimization level may perform better than level-two (-O2) although this case rarely occurs.
The PGI compilers perform many different types of local optimizations, including but not limited to:
"-Munroll=c:n" instructs the compiler to completely unroll loops with a constant loop count of less than or equal to n where n is a supplied constant value. If no constant value is given, then a default of 4 is used.
Inline functions declared with the inline keyword.
Enable an optional post-pass instruction scheduling.
Enables loop-carried redundancy elimination, an optimization that can reduce the number of arithmetic operations and memory references in loops.
Eliminates operations that set up a true stack frame pointer for every function. With this option enabled, you cannot perform a traceback on the generated code and you cannot access local variables.
Instructs the vectorizer to search for vectorizable loops and, where possible, make use of SSE, SSE2, and prefetch instructions.
Enable automatic vector pipelining.
Instructs the vectorizer to enable certain associativity conversions that can change the results of a computations due to roundoff error. A typical optimization is to change an arithmetic operation to an arithmetic opteration that is mathmatically correct, but can be computationally different, due to round-off error.
Instructs the vectorizer to generate alternate code for vectorized loops when appropriate. For each vectorized loop the compiler decides whether to generate altcode and what type or types to generate, which may be any or all of:
The compiler also determines suitable loop count and array alignment conditions for executing the altcode.
Align "unconstrained" data objects of size greater than or equal to 16 bytes on cache-line boundaries. An "unconstrained" object is a variable or array that is not a member of an aggregate structure or common block, is not allocatable, and is not an automatic array. On by default on 64-bit Linux systems.
Set SSE to flush-to-zero mode; if a floating-point underflow occurs, the value is set to zero.
Treat denormalized numbers as zero. Included with "-fast" on Intel based systems. For AMD based systems, "-Mdaz" is not included by default with "-fast".
Use SSE/SSE2 instructions to perform scalar floating-point arithmetic on targets where these instructions are supported.
Interprocedural Analysis option: Recognize when targets of pointer dummy are aligned.
Interprocedural Analysis option: Remove arguments replaced by -Mipa=ptr,const
Interprocedural Analysis option: Enable pointer disambiguation across procedure calls.
Interprocedural Analysis option: Enable interprocedural constant propagation.
Interprocedural Analysis option: Fortran 90/95 Pointer disambiguation across calls.
Interprocedural Analysis option: Perform Fortran 90 array shape propagation.
Interprocedural Analysis option: Optimize references to global values.
Interprocedural Analysis option: Used to optimize calls to certain functions in the system standard C library, libc.
Interprocedural Analysis option: -Mipa=arg plus externalizes local pointer targets.
Interprocedural Analysis option: Pure function detection.
Instructs the compiler to use relaxed precision in the calculation of floating-point reciprocal square root (1/sqrt). Can result in improved performance at the expense of numerical accuracy.
Instructs the compiler to use relaxed precision in the calculation of floating-point square root. Can result in improved performance at the expense of numerical accuracy.
Instructs the compiler to use relaxed precision in the calculation of floating-point division. Can result in improved performance at the expense of numerical accuracy.
Instructs the compiler to allow floating-point expression reordering, including factoring. Can result in improved performance at the expense of numerical accuracy.
Specify the basic level of optimization desired.
The options can be one of the following:
0 Turn off all optimizations.
1 Turn on local optimizations that can be done quickly. Do peephole optimizations and instruction scheduling.
2 Turn on extensive optimization.
This is the default.
The optimizations at this level are generally conservative,
in the sense that they are virtually always beneficial and
avoid changes which affect
such things as floating point accuracy. In addition to the level
1 optimizations, do inner loop
unrolling, if-conversion, two passes of instruction scheduling,
global register allocation, dead store elimination,
instruction scheduling across basic blocks,
and partial redundancy elimination.
3 Turn on aggressive optimization.
The optimizations at this level are distinguished from -O2
by their aggressiveness, generally seeking highest-quality
generated code even if it requires extensive compile time.
They may include optimizations that are generally beneficial
but may hurt performance.
This includes but is not limited to turning on the
Loop Nest Optimizer, -LNO:opt=1, and setting
-OPT:roundoff=1:IEEE_arithmetic=2:Olimit=9000:reorg_common=ON.
s Specify that code size is to be given priority in tradeoffs with execution time.
If no value is specified, 2 is assumed.Invoke inter-procedural analysis (IPA). Specifying this option is identical to specifying -IPA or -IPA:. Default settings for the individual IPA suboptions are used.
-OPT:Ofast
Use optimizations selected to maximize performance.
Although the optimizations are generally safe, they may affect
floating point accuracy due to rearrangement of computations.
This effectively turns on the following optimizations:
-OPT:ro=2:Olimit=0:div_split=ON:alias=typed.
-OPT:roundoff,ro=(0|1|2|3)
Specify the level of acceptable departure from source language
floating-point, round-off, and overflow semantics.
The options can be one of the following:
0 = Inhibit optimizations that might affect the floating-point behavior. This is the default when optimization levels -O0, -O1, and -O2 are in effect.
1 = Allow simple transformations that might cause limited round-off or overflow differences. Compounding such transformations could have more extensive effects. This is the default when -O3 is in effect.
2 = Allow more extensive transformations, such as the reordering of reduction loops. This is the default level when -OPT:Ofast is specified.
3 = Enable any mathematically valid transformation.
-OPT:Olimit=N
Disable optimization when size of program unit is > N. When N is 0,
program unit size is ignored and optimization process will not be
disabled due to compile time limit.
The default is 0 when -OPT:Ofast is specified,
9000 when -O3 is specified; otherwise the default is 6000.
-OPT:div_split=(ON|OFF)
Enable or disable changing x/y into x*(recip(y)). This is OFF by
default, but enabled by -OPT:Ofast or -OPT:IEEE_arithmetic=3.
This transformation generates fairly accurate code.
The -OPT: option group controls miscellaneous optimizations. These options override defaults based on the main optimization level.
-OPT:alias=<name>
Specify the pointer aliasing model
to be used. By specifying one or more of the following for <name>,
the compiler is able to make assumptions throughout the compilation:
typed
Assume that the code adheres to the ANSI/ISO C standard
which states that two pointers of different types cannot point
to the same location in memory.
This is ON by default when -OPT:Ofast is specified.
restrict
Specify that distinct pointers are assumed to point to distinct,
non-overlapping objects. This is OFF by default.
disjoint
Specify that any two pointer expressions are assumed to point
to distinct, non-overlapping objects. This is OFF by default.
Do not set ERRNO after calling math functions that are executed with a single instruction, e.g. sqrt. A program that relies on IEEE exceptions for math error handling may want to use this flag for speed while maintaining IEEE arithmetic compatibility. This is implied by -Ofast. The default is -fmath-errno.
-ffast-math improves FP speed by relaxing ANSI & IEEE rules. -fno-fast-math tells the compiler to conform to ANSI and IEEE math rules at the expense of speed. -ffast- math implies -OPT:IEEE_arithmetic=2 -fno-math-errno. -fno-fast-math implies -OPT:IEEE_arithmetic=1 -fmath-errno.
Instructs the C/C++ compiler to override data dependencies between pointers of a given storage class.
Linux Huge Page settings
In order to take full advantage of using PGI's huge page runtime library, your system must be configured to use huge pages. It is safe to run binaries compiled with "-Msmartalloc=huge" on systems not configured to use huge pages, however, you will not benefit from the performance improvements huge pages offer. To configure your system for huge pages perform the following steps:
Note that further information about huge pages may be found in your Linux documentation file: /usr/src/linux/Documentation/vm/hugetlbpage.txt
PGI_HUGE_PAGES
The maximum number of huge pages an application is allowed to use can be set at run time via the environment variable PGI_HUGE_PAGES. If not set, then the process may use all available huge pages when compiled with "-Msmartalloc=huge" or a maximum of n pages where the value of n is set via the compile time flag "-Msmartalloc=huge:n.
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 effect 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 memory on the local node while "-m" specifies which node(s) to place a process memory. For full details on using numactl, please refer to your Linux documentation, 'man numactl'
Note that some versions of numactl, particularly the version found on SLES 10, we have found that the utility incorrectly interprets application arguments as it's own. For example, with the command "numactl --physcpubind=0 -l a.out -m a", numactl will interpret a.out's "-m" option as it's own "-m" option. To work around this problem, a user can 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"
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.
Flag description origin markings:
For questions about the meanings of these flags, please contact the tester.
For other inquiries, please contact webmaster@spec.org
Copyright 2006-2016 Standard Performance Evaluation Corporation
Tested with SPEC CPU2006 v1.0.
Report generated on Tue Sep 13 11:28:45 2016 by SPEC CPU2006 flags formatter v6906.