CPU2006 Flag Description
IBM Corporation IBM Flex System p260 (4.1 GHz, 16 core)

Base Optimization Flags

C benchmarks

• • -qipa=threads
  • 
  • LDCFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x40000000
  • 
  • LDCFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -O5
  • 
  • COPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -blpdata
  • 
  • LDOPT

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

C++ benchmarks

• • -qipa=threads
  • 
  • LDCXXFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x50000000
  • 
  • LDCXXFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -O5
  • 
  • CXXOPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qsimd
  • 
  • CXXOPTIMIZE

  • Enables the generation of vector instructions for processors that support them.

• • -qvecnvol
  • 
  • CXXOPTIMIZE

  • Specifies whether to use volatile or non-volatile vector registers. Volatile vector registers are registers whose value is not preserved across function calls so the compiler will not depend on values in them across function calls.

• • -D_ILS_MACROS
  • 
  • CXXOPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -qrtti=all
  • 
  • CXXOPTIMIZE

  • Cause the C++ compiler to generate Run Time Type Identification code

• • -D__IBM_FAST_VECTOR
  • 
  • CXXOPTIMIZE

  • The __IBM_FAST_VECTOR macro defines a different iterator for the std::vector template class. This iterator results in faster code, but is not compatible with code using the default iterator for a std::vector template class. All uses of std::vector for a data type must use the same iterator. Add -D__IBM_FAST_VECTOR to the compile line, or "#define __IBM_FAST_VECTOR 1" to your source code to use the faster iterator for std::vector template class. You must compile all sources with this macro.

• • -D__IBM_FAST_SET_MAP_ITERATOR
  • 
  • CXXOPTIMIZE

  • The __IBM_FAST_SET_MAP_ITERATOR macro defines a different iterator for the std::vector template class. This iterator results in faster code, but is not compatible with code using the default iterator for a std::vector template class. All uses of std::vector for a data type must use the same iterator. Add -D__IBM_FAST_SET_MAP_ITERATOR to the compile line, or "#define __IBM_FAST_SET_MAP_ITERATOR 1" to your source code to use the faster iterator for std::vector template class. You must compile all sources with this macro.

• • -blpdata
  • 
  • LDOPT

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

Fortran benchmarks

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x60000000
  • 
  • LDFFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -O5
  • 
  • FOPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qsmallstack=dynlenonheap
  • 
  • FOPTIMIZE

  • Causes the Fortran compiler to allocate dynamic arrays on the heap instead of the stack

• • -qalias=nostd
  • 
  • FOPTIMIZE

  •  qalias=ansi | noansi
       If ansi is specified, type-based aliasing is
       used during optimization, which restricts the
       lvalues that can be safely used to access a
       data object. The default is ansi for the xlc,
       xlC, and c89 commands. This option has no
       effect unless you also specify the -O option.
    
     qalias=std |nostd
       Indicates whether the compilation units contain
       any non-standard aliasing (see Compiler Reference
       for more information). If so, specify nostd. 
    

• • -blpdata
  • 
  • LDOPT

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

Benchmarks using both Fortran and C

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x60000000
  • 
  • LDFFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -O5
  • 
  • COPTIMIZE, FOPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -qsmallstack=dynlenonheap
  • 
  • FOPTIMIZE

  • Causes the Fortran compiler to allocate dynamic arrays on the heap instead of the stack

• • -qalias=nostd
  • 
  • FOPTIMIZE

  •  qalias=ansi | noansi
       If ansi is specified, type-based aliasing is
       used during optimization, which restricts the
       lvalues that can be safely used to access a
       data object. The default is ansi for the xlc,
       xlC, and c89 commands. This option has no
       effect unless you also specify the -O option.
    
     qalias=std |nostd
       Indicates whether the compilation units contain
       any non-standard aliasing (see Compiler Reference
       for more information). If so, specify nostd. 
    

• • -blpdata
  • 
  • LDOPT

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

Peak Optimization Flags

C benchmarks

433.milc

• • -qipa=threads
  • 
  • LDCFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x40000000
  • 
  • LDCFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -qprefetch=aggressive
  • 
  • COPTIMIZE

  •  qprefetch=aggressive
       Aggressively prefetch data
    

• • -qalign=natural
  • 
  • COPTIMIZE

  •            Specifies what aggregate alignment rules the
                    compiler uses for file compilation, where the
                    alignment options are:
    
                    bit_packed
                         The compiler uses the bit_packed alignment
                         rules.
                    full
                         The compiler uses the RISC System/6000
                         alignment rules. This is the same as power.
                    mac68k
                         The compiler uses the Macintosh alignment
                         rules.  This suboption is valid only for 32-
                         bit compilations.
                    natural
                         The compiler maps structure members to their
                         natural boundaries.
                    packed
                         The compiler uses the packed alignment rules.
                    power
                         The compiler uses the RISC System/6000
                         alignment rules.
                    twobyte
                         The compiler uses the Macintosh alignment
                         rules.  This suboption is valid only for 32-
                         bit compilations.  The mac68k option is the
                         same as twobyte.
    
                    The default is -qalign=full.
    

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

470.lbm

• • -qipa=threads
  • 
  • LDCFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x30000000
  • 
  • LDCFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

482.sphinx3

• • -qpdf1
  • 
  • PASS1_CFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_CFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

C++ benchmarks

444.namd

• • -qipa=threads
  • 
  • LDCXXFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -O4
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.

    -O4 is equivalent to the following flags
    • -O3
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
  • Includes:
    • -O3
      • -O2
        • -O
      • -qhot=level=0
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
• • -q64
  • 
  • OPTIMIZE

  • Generates 64 bit ABI binaries. The default is to generate 32 bit ABI binaries.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -D_ILS_MACROS
  • 
  • CXXOPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -D__IBM_FAST_VECTOR
  • 
  • CXXOPTIMIZE

  • The __IBM_FAST_VECTOR macro defines a different iterator for the std::vector template class. This iterator results in faster code, but is not compatible with code using the default iterator for a std::vector template class. All uses of std::vector for a data type must use the same iterator. Add -D__IBM_FAST_VECTOR to the compile line, or "#define __IBM_FAST_VECTOR 1" to your source code to use the faster iterator for std::vector template class. You must compile all sources with this macro.

• • -D__IBM_FAST_SET_MAP_ITERATOR
  • 
  • CXXOPTIMIZE

  • The __IBM_FAST_SET_MAP_ITERATOR macro defines a different iterator for the std::vector template class. This iterator results in faster code, but is not compatible with code using the default iterator for a std::vector template class. All uses of std::vector for a data type must use the same iterator. Add -D__IBM_FAST_SET_MAP_ITERATOR to the compile line, or "#define __IBM_FAST_SET_MAP_ITERATOR 1" to your source code to use the faster iterator for std::vector template class. You must compile all sources with this macro.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

447.dealII

• • basepeak = yes

450.soplex

• • -qipa=threads
  • 
  • LDCXXFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x40000000
  • 
  • LDCXXFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qsimd
  • 
  • OPTIMIZE

  • Enables the generation of vector instructions for processors that support them.

• • -qvecnvol
  • 
  • OPTIMIZE

  • Specifies whether to use volatile or non-volatile vector registers. Volatile vector registers are registers whose value is not preserved across function calls so the compiler will not depend on values in them across function calls.

• • -D_ILS_MACROS
  • 
  • CXXOPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -D__IBM_FAST_VECTOR
  • 
  • CXXOPTIMIZE

  • The __IBM_FAST_VECTOR macro defines a different iterator for the std::vector template class. This iterator results in faster code, but is not compatible with code using the default iterator for a std::vector template class. All uses of std::vector for a data type must use the same iterator. Add -D__IBM_FAST_VECTOR to the compile line, or "#define __IBM_FAST_VECTOR 1" to your source code to use the faster iterator for std::vector template class. You must compile all sources with this macro.

• • -D__IBM_FAST_SET_MAP_ITERATOR
  • 
  • CXXOPTIMIZE

  • The __IBM_FAST_SET_MAP_ITERATOR macro defines a different iterator for the std::vector template class. This iterator results in faster code, but is not compatible with code using the default iterator for a std::vector template class. All uses of std::vector for a data type must use the same iterator. Add -D__IBM_FAST_SET_MAP_ITERATOR to the compile line, or "#define __IBM_FAST_SET_MAP_ITERATOR 1" to your source code to use the faster iterator for std::vector template class. You must compile all sources with this macro.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

453.povray

• • -qipa=threads
  • 
  • LDCXXFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -qpdf1
  • 
  • PASS1_CXXFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O4
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.

    -O4 is equivalent to the following flags
    • -O3
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
  • Includes:
    • -O3
      • -O2
        • -O
      • -qhot=level=0
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
• • -qsimd
  • 
  • OPTIMIZE

  • Enables the generation of vector instructions for processors that support them.

• • -qvecnvol
  • 
  • OPTIMIZE

  • Specifies whether to use volatile or non-volatile vector registers. Volatile vector registers are registers whose value is not preserved across function calls so the compiler will not depend on values in them across function calls.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -D_ILS_MACROS
  • 
  • CXXOPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -qalign=natural
  • 
  • CXXOPTIMIZE

  •            Specifies what aggregate alignment rules the
                    compiler uses for file compilation, where the
                    alignment options are:
    
                    bit_packed
                         The compiler uses the bit_packed alignment
                         rules.
                    full
                         The compiler uses the RISC System/6000
                         alignment rules. This is the same as power.
                    mac68k
                         The compiler uses the Macintosh alignment
                         rules.  This suboption is valid only for 32-
                         bit compilations.
                    natural
                         The compiler maps structure members to their
                         natural boundaries.
                    packed
                         The compiler uses the packed alignment rules.
                    power
                         The compiler uses the RISC System/6000
                         alignment rules.
                    twobyte
                         The compiler uses the Macintosh alignment
                         rules.  This suboption is valid only for 32-
                         bit compilations.  The mac68k option is the
                         same as twobyte.
    
                    The default is -qalign=full.
    

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

Fortran benchmarks

410.bwaves

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x50000000
  • 
  • LDFFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -qsmallstack=dynlenonheap
  • 
  • FOPTIMIZE

  • Causes the Fortran compiler to allocate dynamic arrays on the heap instead of the stack

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

416.gamess

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x40000000
  • 
  • LDFFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -qpdf1
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qarch=pwr5
  • 
  • OPTIMIZE

  • Produces object code containing instructions that will run on the specified processors. "auto" selects the processor the compile is being done on. "pwr5x" is the POWER5+ processor.

    Supported values for this flag are

    • auto - Use the processor on which the program is compiled.
    • pwr7 - The POWER7 processor based systems.
    • pwr6e - The POWER6 processor in "Enhanced" mode based systems.
    • pwr6 - The POWER6 processor based systems.
    • pwr5x - The POWER5+ processor based systems.
    • pwr5 - The POWER5 processor based systems.
    • pwr4 - The POWER4 processor based systems.
    • ppc970 - The PPC970 processor based systems.
• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -qalias=nostd
  • 
  • FOPTIMIZE

  •  qalias=ansi | noansi
       If ansi is specified, type-based aliasing is
       used during optimization, which restricts the
       lvalues that can be safely used to access a
       data object. The default is ansi for the xlc,
       xlC, and c89 commands. This option has no
       effect unless you also specify the -O option.
    
     qalias=std |nostd
       Indicates whether the compilation units contain
       any non-standard aliasing (see Compiler Reference
       for more information). If so, specify nostd. 
    

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

434.zeusmp

• • -bmaxdata:0x40000000
  • 
  • LDFFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -qpdf1
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O3
  • 
  • OPTIMIZE
  • -O3 Performs additional optimizations that are memory intensive, compile-time intensive, and may change the semantics of the program slightly, unless -qstrict is specified. We recommend these optimizations when the desire for run-time speed improvements outweighs the concern for limiting compile-time resources. The optimizations provided include:
    • In-depth memory access analysis
    • Better loop scheduling
    • High-order loop analysis and transformations (-qhot=level=0)
    • Inlining of small procedures within a compilation unit by default
    • Eliminating implicit compile-time memory usage limits
    • Widening, which merges adjacent load/stores and other operations
    • Pointer aliasing improvements to enhance other optimizations
    -O3 is equivalent to the following flags
    • -O2
    • -qhot=level=0
  • Includes:
    • -O2
      • -O
        • -O2
    • -qhot=level=0
• • -qarch=auto
  • 
  • OPTIMIZE

  • Produces object code containing instructions that will run on the specified processors. "auto" selects the processor the compile is being done on. "pwr5x" is the POWER5+ processor.

    Supported values for this flag are

    • auto - Use the processor on which the program is compiled.
    • pwr7 - The POWER7 processor based systems.
    • pwr6e - The POWER6 processor in "Enhanced" mode based systems.
    • pwr6 - The POWER6 processor based systems.
    • pwr5x - The POWER5+ processor based systems.
    • pwr5 - The POWER5 processor based systems.
    • pwr4 - The POWER4 processor based systems.
    • ppc970 - The PPC970 processor based systems.
• • -qtune=auto
  • 
  • OPTIMIZE

  • Specifies the system architecture for which the executable program is optimized. This includes instruction scheduling and cache setting.

    The supported values for suboption are

    • auto - Use the processor on which the program is compiled.
    • pwr7 - The POWER7 processor based systems.
    • pwr6e - The POWER6 processor in "Enhanced" mode based systems.
    • pwr6 - The POWER6 processor based systems.
    • pwr5x - The POWER5+ processor based systems.
    • pwr5 - The POWER5 processor based systems.
    • pwr4 - The POWER4 processor based systems.
    • ppc970 - The PPC970 processor based systems.
• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -qxlf90=nosignedzero
  • 
  • FOPTIMIZE

  •          -qxlf90=<suboption>
                    Determines whether the compiler provides the
                    Fortran 90 or the Fortran 95 level of support for
                    certain aspects of the language. <suboption> can be
                    one of the following:
    
                    signedzero | nosignedzero
                         Determines how the SIGN(A,B) function handles
                         signed real 0.0. In addition, determines
                         whether negative internal values will be
                         prefixed with a minus when formatted output
                         would produce a negative sign zero.
                    autodealloc | noautodealloc
                         Determines whether the compiler deallocates
                         allocatable arrays that are declared locally
                         without either the SAVE or the STATIC
                         attribute and have a status of currently
                         allocated when the subprogram terminates.
                    oldpad | nooldpad
                         When the PAD=specifier is present in the
                         INQUIRE statement, specifying -qxlf90=nooldpad
                         returns UNDEFINED when there is no connection,
                         or when the connection is for unformatted I/O.
                         This behavior conforms with the Fortran 95
                         standard and above. Specifying -qxlf90=oldpad
                         preserves the Fortran 90 behavior.
    
                    Default:
                         o signedzero, autodealloc and nooldpad for the
                         xlf95, xlf95_r, xlf95_r7 and f95 invocation
                         commands.
                         o nosignedzero, noautodealloc and oldpad for
                         all other invocation commands.
    

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

437.leslie3d

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -qpdf1
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

459.GemsFDTD

• • -qpdf1
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O4
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.

    -O4 is equivalent to the following flags
    • -O3
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
  • Includes:
    • -O3
      • -O2
        • -O
      • -qhot=level=0
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
• • -q64
  • 
  • OPTIMIZE

  • Generates 64 bit ABI binaries. The default is to generate 32 bit ABI binaries.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

465.tonto

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x50000000
  • 
  • LDFFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -qpdf1
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qsimd
  • 
  • OPTIMIZE

  • Enables the generation of vector instructions for processors that support them.

• • -qvecnvol
  • 
  • OPTIMIZE

  • Specifies whether to use volatile or non-volatile vector registers. Volatile vector registers are registers whose value is not preserved across function calls so the compiler will not depend on values in them across function calls.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

Benchmarks using both Fortran and C

435.gromacs

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -qpdf1
  • 
  • PASS1_CFLAGS, PASS1_FFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_CFLAGS, PASS2_FFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

436.cactusADM

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -bmaxdata:0x60000000
  • 
  • LDFFLAGS

  • Causes the system loader to put the heap in it's own segment of the size specified. This is only required for 32-bit applications, as their segments are 256M. If the last digit of the value is "C", then it also turns off the malloc pool option for that executable.

• • -O4
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes interprocedural analysis on all of the objects presented on the "link" step.

    -O4 is equivalent to the following flags
    • -O3
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
  • Includes:
    • -O3
      • -O2
        • -O
      • -qhot=level=0
    • -qipa=level=1
    • -qarch=auto
    • -qtune=auto
• • -qsimd
  • 
  • OPTIMIZE

  • Enables the generation of vector instructions for processors that support them.

• • -qvecnvol
  • 
  • OPTIMIZE

  • Specifies whether to use volatile or non-volatile vector registers. Volatile vector registers are registers whose value is not preserved across function calls so the compiler will not depend on values in them across function calls.

• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -qnostrict
  • 
  • COPTIMIZE, FOPTIMIZE

  •                 Ensures that optimizations done by default at
                    optimization levels -O3 and higher, and, optionally
                    at -O2, do not alter the semantics of a program.
    
                    The -qstrict=all, -qstrict=precision,
                    -qstrict=exceptions, -qstrict=ieeefp, and
                    -qstrict=order suboptions and their negative forms
                    are group suboptions that affect multiple,
                    individual suboptions. Group suboptions act as if
                    either the positive or the no form of every
                    suboption of the group is specified.
    
                    Default:
    
                         o Always -qstrict or -qstrict=all when the
                         -qnoopt or -O0 optimization level is in effect
                         o -qstrict or -qstrict=all is the default when
                         the -O2 or -O optimization level is in effect
                         o -qnostrict or -qstrict=none is the default
                         when -O3 or a higher optimization level is in
                         effect
    
                    <suboptions_list> is a colon-separated list of one
                    or more of the following:
    
                    all | none
                         all disables all semantics-changing
                         transformations, including those controlled by
                         the ieeefp, order, library, precision, and
                         exceptions suboptions.  none enables these
                         transformations.
                    precision | noprecision
                         precision disables all transformations that
                         are likely to affect floating-point precision,
                         including those controlled by the subnormals,
                         operationprecision, association,
                         reductionorder, and library suboptions.
                         noprecision enables these transformations.
                    exceptions | noexceptions
                         exceptions disables all transformations likely
                         to affect exceptions or be affected by them,
                         including those controlled by the nans,
                         infinities, subnormals, guards, and library
                         suboptions. noexceptions enables these
                         transformations.
                    ieeefp | noieeefp
                         ieeefp disables transformations that affect
                         IEEE floating-point compliance, including
                         those controlled by the nans, infinities,
                         subnormals, zerosigns, and operationprecision
                         suboptions. noieeefp enables these
                         transformations.
                    nans | nonans
                         nans disables transformations that may produce
                         incorrect results in the presence of, or that
                         may incorrectly produce IEEE floating-point
                         signaling NaN (not-a-number) values. nonans
                         enables these transformations.
                    infinities | noinfinities
                         infinities disables transformations that may
                         produce incorrect results in the presence of,
                         or that may incorrectly produce floating-point
                         infinities.  noinfinities enables these
                         transformations.
                    subnormals | nosubnormals
                         subnormals disables transformations that may
                         produce incorrect results in the presence of,
                         or that may incorrectly produce IEEE
                         floating-point subnormals (formerly known as
                         denorms). nosubnormals enables these
                         transformations.
                    zerosigns | nozerosigns
                         zerosigns disables transformations that may
                         affect or be affected by whether the sign of a
                         floating-point zero is correct. nozerosigns
                         enables these transformations.
                    operationprecision | nooperationprecision
                         operationprecision disables transformations
                         that produce approximate results for
                         individual floating-point operations.
                         nooperationprecision enables these
                         transformations.
                    order | noorder
                         order disables all code reordering between
                         multiple operations that may affect results or
                         exceptions, including those controlled by the
                         association, reductionorder, and guards
                         suboptions. noorder enables code reordering.
                    association | noassociation
                         association disables reordering operations
                         within an expression. noassociation enables
                         reordering operations.
                    reductionorder | noreductionorder
                         reductionorder disables parallelizing
                         floating-point reductions. noreductionorder
                         enables these reductions.
                    guards | noguards
                         guards disables moving operations past guards
                         or calls which control whether the operation
                         should be executed or not. enables these
                         moving operations.
                    library | nolibrary
                         library disables transformations that affect
                         floating-point library functions. nolibrary
                         enables these transformations.
    
    

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

454.calculix

• • -qipa=threads
  • 
  • LDFFLAGS

  • The threads suboption allows the IPA optimizer to run portions of the optimization process in parallel threads, which can speed up the compilation process on multi-processor systems. All the available threads, or the number specified by N, may be used. N must be a positive integer. Specifying nothreads does not run any parallel threads; this is equivalent to running one serial thread. This option does not affect the code in the final binary created.

• • -qpdf1
  • 
  • PASS1_CFLAGS, PASS1_FFLAGS, PASS1_LDFLAGS

  • The option used in the first pass of a profile directed feedback compile that causes pdf information to be generated. The profile directed feedback optimization gathers data on both execution path and data values. It does not use hardware counters, nor gather any data other than path and data values for PDF specific optimizations.

• • -qpdf2
  • 
  • PASS2_CFLAGS, PASS2_FFLAGS, PASS2_LDFLAGS

  • The option used in the second pass of a profile directed feedback compile that causes PDF information to be utilized during optimization.

• • -O5
  • 
  • OPTIMIZE

  • Perform optimizations for maximum performance. This includes maximum interprocedural analysis on all of the objects presented on the "link" step. This level of optimization will increase the compiler's memory usage and compile time requirements. -O5 Provides all of the functionality of the -O4 option, but also provides the functionality of the -qipa=level=2 option.

    -O5 is equivalent to the following flags
    • -O4
    • -qipa=level=2
  • Includes:
    • -O4
      • -O3
        • -O2
          • -O
        • -qhot=level=0
      • -qipa=level=1
      • -qarch=auto
      • -qtune=auto
    • -qipa=level=2
• • -qsimd
  • 
  • OPTIMIZE

  • Enables the generation of vector instructions for processors that support them.

• • -qvecnvol
  • 
  • OPTIMIZE

  • Specifies whether to use volatile or non-volatile vector registers. Volatile vector registers are registers whose value is not preserved across function calls so the compiler will not depend on values in them across function calls.

• • -qlargepage
  • 
  • OPTIMIZE

  • Indicates that a program, designed to execute in a large page memory environment, can take advantage of large 16 MB pages provided on POWER4 and higher based systems.

• • -D_ILS_MACROS
  • 
  • COPTIMIZE

  • Causes AIX to define "ischar()" (and friends) as macro's and not subroutines.

• • -blpdata
  • 
  • EXTRA_LDFLAGS

  • Sets the bit in the file's XCOFF header indicating that this executable will request the use of large pages when they are available on the system and when the user has an appropriate privilege

• • -btextpsize:64K
  • 
  • EXTRA_LDFLAGS

  • Specifies a non-default page size of 64K for the program text segment.

481.wrf

• • basepeak = yes