The PGI C compiler.
The PGI C++ compiler.
The PGI C compiler.
The PGI C++ compiler.
This macro specifies that the target system uses the LP64 data model; specifically, that integers are 32 bits, while longs and pointers are 64 bits.
This macro indicates that the benchmark is being compiled on an AMD64-compatible system running the Linux operating 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.
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.
Portability changes for Linux
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 flag can be set for SPEC compilation for Linux using default compiler.
This macro specifies that the target system uses the LP64 data model; specifically, that integers are 32 bits, while longs and pointers are 64 bits.
This macro indicates that the benchmark is being compiled on an AMD64-compatible system running the Linux operating 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.
Portability changes for Linux
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 flag can be set for SPEC compilation for Linux using default compiler.
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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
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"
Aligns or does not align innermost loops on 32 byte boundaries with -tp barcelona. Small loops on barcelona systems may run fast if aligned on 32-byte boundaries; however, in practice, most assemblers do not yet implement efficient padding causing some programs to run more slowly with this as default. Use -Mloop32 on systems with an assembler tuned for barcleona. The default is -Mnoloop32.
Enable parallelization of innermost loops.
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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
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"
Aligns or does not align innermost loops on 32 byte boundaries with -tp barcelona. Small loops on barcelona systems may run fast if aligned on 32-byte boundaries; however, in practice, most assemblers do not yet implement efficient padding causing some programs to run more slowly with this as default. Use -Mloop32 on systems with an assembler tuned for barcleona. The default is -Mnoloop32.
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 32-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.
Enable profile-feedback optimizations.
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
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 "-Mscalarsse", "-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.
Disable loop unrolling.
Disable automatic vector pipelining.
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.
Enable parallelization of innermost loops.
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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Link with the huge page runtime library and allocate a maximum n huge pages.
Disable loop unrolling.
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.
Enable profile-feedback optimizations.
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
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.
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 "-Mscalarsse", "-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.
Specify the type of the target processor as AMD64 Barcelona Processor 32-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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
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, limit to n levels. IPA-based function inlining is performed from leaf routines upward.
Link with the huge page runtime library and allocate a maximum n huge pages.
Aligns or does not align innermost loops on 32 byte boundaries with -tp barcelona. Small loops on barcelona systems may run fast if aligned on 32-byte boundaries; however, in practice, most assemblers do not yet implement efficient padding causing some programs to run more slowly with this as default. Use -Mloop32 on systems with an assembler tuned for barcleona. The default is -Mnoloop32.
Specify the type of the target processor as AMD64 Barcelona Processor 32-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.
Enable profile-feedback optimizations.
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Link with the huge page runtime library and allocate a maximum n huge pages.
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"
Disable automatic vector pipelining.
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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
"-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.
Link with the huge page runtime library and allocate a maximum n huge pages.
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"
Instructs the vectorizer to generate partial vectorization.
Instructs the C/C++ compiler to override data dependencies between pointers of a given storage class.
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
Interprocedural Analysis option: Enable interprocedural constant propagation.
Interprocedural Analysis option: Enable pointer disambiguation across procedure calls.
Interprocedural Analysis option: Remove arguments replaced by -Mipa=ptr,const
Interprocedural Analysis option: Automatically determine which functions to inline. IPA-based function inlining is performed from leaf routines upward.
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.
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
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, limit to n levels. 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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Link with the huge page runtime library and allocate a maximum n huge pages.
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"
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 "-Mscalarsse", "-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"
Adds a call to the routine "mallopt" in the main routine. This option can have a dramatic impact on the performance of programs that dynamically allocate memory, especially for those which have a few large mallocs. To be effective, this switch must be specified when compiling the file containing the Fortran, C, or C++ main routine.
Instructs the driver to disable the -Mvect=sse option which is part of the "-fast" option.
"-Munroll=m:n" instructs the compiler to unroll loops with multiple blocks n times where n is a supplied constant value. If no constant value is given, then a default of 4 is used.
Enable parallelization of innermost loops.
Always execute the parallelized version of a loop regardless of the loop count.
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
Instructs the compiler to perform interprocedural analysis. Equivalant to -Mipa=align,arg,const,f90ptr,shape,globals,libc,localarg,ptr,pure.
Interprocedural Analysis option: Do not remove arguments replaced by -Mipa=ptr,const
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.
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
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.
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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Link with the huge page runtime library and allocate a maximum n huge pages.
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"
Aligns or does not align innermost loops on 32 byte boundaries with -tp barcelona. Small loops on barcelona systems may run fast if aligned on 32-byte boundaries; however, in practice, most assemblers do not yet implement efficient padding causing some programs to run more slowly with this as default. Use -Mloop32 on systems with an assembler tuned for barcleona. The default is -Mnoloop32.
Generate zero-overhead C++ exception handlers.
Specify the type of the target processor as AMD64 Barcelona Processor 32-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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Interprocedural Analysis option: Specifies the number of concurent IPA second pass compliation proccess that may be performed. This option speeds-up the compilation time on multi-core systems but does not perform any optimizations.
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"
Adds a call to the routine "mallopt" in the main routine. This option can have a dramatic impact on the performance of programs that dynamically allocate memory, especially for those which have a few large mallocs. To be effective, this switch must be specified when compiling the file containing the Fortran, C, or C++ main routine.
Aligns or does not align innermost loops on 32 byte boundaries with -tp barcelona. Small loops on barcelona systems may run fast if aligned on 32-byte boundaries; however, in practice, most assemblers do not yet implement efficient padding causing some programs to run more slowly with this as default. Use -Mloop32 on systems with an assembler tuned for barcleona. The default is -Mnoloop32.
Generate zero-overhead C++ exception handlers.
Specify the type of the target processor as AMD64 Barcelona Processor 32-bit mode.
Staticily link with the PGI runtime libraries. System libraries may still be dynamically linked.
-L
when used as an EXTRA_CLIB or EXTRA_CXXLIB variable,
results in linking with MicroQuill's SmartHeap 8 (32-bit) library
for Linux. This is a library that optimizes calls to new, delete, malloc and free.
Disable warning messages.
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.
The MP_BIND environment variable can be set to yes or y to bind processes or threads executing in a parallel region to physical processors, or to no or n to disable such binding. The default is to not bind processes to processors. This is an execution time environment variable interpreted by the PGI runtime support libraries. It does not affect the behavior of the PGI compilers in any way. Note: the MP_BIND environment variable is not supported on all platforms.
In addition to the MP_BIND variable, it is possible to define the thread-CPU relationship. For example, setting MP_BLIST=3,2,1,0 maps CPUs 3, 2, 1 and 0 to threads 0, 1, 2 and 3 respectively.
The NCPUS environment variable can be used to set the number of processes or threads used in parallel regions. The default is to use only one process or thread (serial mode). If both OMP_NUM_THREADS and NCPUS are set, the value of OMP_NUM_THREADS takes precedence. Warning: setting NCPUS to a value larger than the number of physical processors or cores in your system can cause parallel programs to run very slowly.
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 "-Mscalarsse", "-Mcache_align", or "-Mvect=sse".
Platform settings
One or more of the following settings may have been set. If so, the "Platform Notes" section of the report will say so; and you can read below to find out more about what these settings mean.
Power Regulator for ProLiant support (Default=HP Dynamic Power Savings Mode)
Values for this BIOS setting can be:
Node Interleaving Enabled (Default = Disabled):
This BIOS option allows the enabling/disabling of memory interleaving across CPU nodes. When disabled, each CPU chip can only access memory within its own node.
submit = echo "$command" > run.sh ; $BIND bash run.sh
When running multiple copies of benchmarks, the SPEC config file feature submit is sometimes used to cause individual jobs to be bound to specific processors. This specific submit command is used for Linux. The description of the elements of the command are:
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.
NCPUS
Sets the maximum number of OpenMP parallel threads auto-parallelized (-Mconcur) applications may use.
Flag description origin markings:
For questions about the meanings of these flags, please contact the tester.
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Copyright 2006-2014 Standard Performance Evaluation Corporation
Tested with SPEC CPU2006 v1.0.
Report generated on Tue Jul 22 17:53:11 2014 by SPEC CPU2006 flags formatter v6906.