CPU2006 Flag Description
Dell Inc. Dell Precision R5400 (Intel Xeon X5270, 3.50 GHz)

Base Optimization Flags

C benchmarks

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qparallel
  • 
  • Yes
  • OPTIMIZE

  • This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
    To use this option, you must also specify option O2 or O3.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • /F512000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

C++ benchmarks

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qparallel
  • 
  • Yes
  • OPTIMIZE

  • This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
    To use this option, you must also specify option O2 or O3.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • -Qcxx_features
  • 
  • CXXOPTIMIZE

  • Enable C++ Exception Handling and RTTI
    This option has the same effect as specifying /GX /GR.

  • Includes:
    • -GX
    • -GR
• • /F512000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

• • shlw64m.lib
  • 
  • EXTRA_LIBS

  • 64-bit MicroQuill SmartHeap Library for Windows available from http://www.microquill.com/

• • -link /FORCE:MULTIPLE
  • 
  • LDOUT

  • Enable SmartHeap library usage by forcing the linker to ignore multiple definitions

Fortran benchmarks

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qparallel
  • 
  • Yes
  • OPTIMIZE

  • This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
    To use this option, you must also specify option O2 or O3.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

Benchmarks using both Fortran and C

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qparallel
  • 
  • Yes
  • OPTIMIZE

  • This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
    To use this option, you must also specify option O2 or O3.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

Peak Optimization Flags

C benchmarks

433.milc

• • basepeak = yes

470.lbm

• • basepeak = yes

482.sphinx3

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qunroll2
  • 
  • OPTIMIZE

  • Tells the compiler the maximum number of times to unroll loops.
    If you do not specify n, the optimizer determines how many times loops can be unrolled.

• • /F512000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

C++ benchmarks

444.namd

• • -Qprof_gen
  • 
  • PASS1_CXXFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Oa
  • 
  • OPTIMIZE

  • This option tells the compiler to assume there is no aliasing.

• • /F512000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

• • shlw64m.lib
  • 
  • EXTRA_LIBS

  • 64-bit MicroQuill SmartHeap Library for Windows available from http://www.microquill.com/

• • -link /FORCE:MULTIPLE
  • 
  • LDOUT

  • Enable SmartHeap library usage by forcing the linker to ignore multiple definitions

447.dealII

• • -Qprof_gen
  • 
  • PASS1_CXXFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qunroll2
  • 
  • OPTIMIZE

  • Tells the compiler the maximum number of times to unroll loops.
    If you do not specify n, the optimizer determines how many times loops can be unrolled.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • -Qansi-alias
  • 
  • OPTIMIZE

  • This option tells the compiler to assume that the program adheres to ISO C Standard aliasability rules. If your program adheres to these rules, then this option allows the compiler to optimize more aggressively. If it doesn't adhere to these rules, then it can cause the compiler to generate incorrect code.

• • -Qscalar-rep-
  • 
  • OPTIMIZE

  • This option enables scalar replacement performed during loop transformation. To use this option, you must also specify O3. -Qscalar-rep- disables this feature. (default)

• • /F512000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

• • shlw64m.lib
  • 
  • EXTRA_LIBS

  • 64-bit MicroQuill SmartHeap Library for Windows available from http://www.microquill.com/

• • -link /FORCE:MULTIPLE
  • 
  • LDOUT

  • Enable SmartHeap library usage by forcing the linker to ignore multiple definitions

450.soplex

• • -Qprof_gen
  • 
  • PASS1_CXXFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • OPTIMIZE, PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE, PASS2_CXXFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • /F512000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

• • shlw64m.lib
  • 
  • EXTRA_LIBS

  • 64-bit MicroQuill SmartHeap Library for Windows available from http://www.microquill.com/

• • -link /FORCE:MULTIPLE
  • 
  • LDOUT

  • Enable SmartHeap library usage by forcing the linker to ignore multiple definitions

453.povray

• • -Qprof_gen
  • 
  • PASS1_CXXFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_CXXFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qunroll4
  • 
  • OPTIMIZE

  • Tells the compiler the maximum number of times to unroll loops.
    If you do not specify n, the optimizer determines how many times loops can be unrolled.

• • -Qansi-alias
  • 
  • OPTIMIZE

  • This option tells the compiler to assume that the program adheres to ISO C Standard aliasability rules. If your program adheres to these rules, then this option allows the compiler to optimize more aggressively. If it doesn't adhere to these rules, then it can cause the compiler to generate incorrect code.

• • /F512000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

• • shlw64m.lib
  • 
  • EXTRA_LIBS

  • 64-bit MicroQuill SmartHeap Library for Windows available from http://www.microquill.com/

• • -link /FORCE:MULTIPLE
  • 
  • LDOUT

  • Enable SmartHeap library usage by forcing the linker to ignore multiple definitions

Fortran benchmarks

410.bwaves

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • -Qparallel
  • 
  • Yes
  • OPTIMIZE

  • This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
    To use this option, you must also specify option O2 or O3.

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

416.gamess

• • -Qprof_gen
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qunroll2
  • 
  • OPTIMIZE

  • Tells the compiler the maximum number of times to unroll loops.
    If you do not specify n, the optimizer determines how many times loops can be unrolled.

• • -Ob0
  • 
  • OPTIMIZE

  • Specifies the level of inline function expansion.

    Ob0 - Disables inlining of user-defined functions. Note that statement functions are always inlined.

    Ob1 - Enables inlining when an inline keyword or an inline attribute is specified. Also enables inlining according to the C++ language.

    Ob2 - Enables inlining of any function at the compiler's discretion.

• • -Qansi-alias
  • 
  • OPTIMIZE

  • This option tells the compiler to assume that the program adheres to ISO C Standard aliasability rules. If your program adheres to these rules, then this option allows the compiler to optimize more aggressively. If it doesn't adhere to these rules, then it can cause the compiler to generate incorrect code.

• • -Qscalar-rep-
  • 
  • OPTIMIZE

  • This option enables scalar replacement performed during loop transformation. To use this option, you must also specify O3. -Qscalar-rep- disables this feature. (default)

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

434.zeusmp

• • basepeak = yes

437.leslie3d

• • basepeak = yes

459.GemsFDTD

• • -Qprof_gen
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qunroll2
  • 
  • OPTIMIZE

  • Tells the compiler the maximum number of times to unroll loops.
    If you do not specify n, the optimizer determines how many times loops can be unrolled.

• • -Ob0
  • 
  • OPTIMIZE

  • Specifies the level of inline function expansion.

    Ob0 - Disables inlining of user-defined functions. Note that statement functions are always inlined.

    Ob1 - Enables inlining when an inline keyword or an inline attribute is specified. Also enables inlining according to the C++ language.

    Ob2 - Enables inlining of any function at the compiler's discretion.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • -Qparallel
  • 
  • Yes
  • OPTIMIZE

  • This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
    To use this option, you must also specify option O2 or O3.

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

465.tonto

• • -Qprof_gen
  • 
  • PASS1_FFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_FFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qunroll4
  • 
  • OPTIMIZE

  • Tells the compiler the maximum number of times to unroll loops.
    If you do not specify n, the optimizer determines how many times loops can be unrolled.

• • -Qauto
  • 
  • OPTIMIZE
  • This option places local variables, except those declared as SAVE, to the run-time stack. It is as if the variables were declared with the AUTOMATIC attribute.
    
    It does not affect variables that have the SAVE attribute or ALLOCATABLE attribute, or variables that appear in an EQUIVALENCE statement or in a common block.
    
    This option may provide a performance gain for your program, but if your program depends on variables having the same value as the last time the routine was invoked, your program may not function properly.
    
    If you want to cause variables to be placed in static memory, specify /Qsave (Windows).
• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

Benchmarks using both Fortran and C

435.gromacs

• • -Qprof_gen
  • 
  • PASS1_CFLAGS, PASS1_FFLAGS, PASS1_LDFLAGS

  • Instrument program for profiling for the first phase of two-phase profile guided otimization. This instrumentation gathers information about a program's execution paths and data values but does not gather information from hardware performance counters. The profile instrumentation also gathers data for optimizations which are unique to profile-feedback optimization.

• • -QxSSE4.1
  • 
  • PASS2_CFLAGS, PASS2_FFLAGS, PASS2_LDFLAGS

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • PASS2_CFLAGS, PASS2_FFLAGS, PASS2_LDFLAGS

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qprof_use
  • 
  • PASS2_CFLAGS, PASS2_FFLAGS, PASS2_LDFLAGS

  • Instructs the compiler to produce a profile-optimized executable and merges available dynamic information (.dyn) files into a pgopti.dpi file. If you perform multiple executions of the instrumented program, -Qprof_use merges the dynamic information files again and overwrites the previous pgopti.dpi file.
    Without any other options, the current directory is searched for .dyn files

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

436.cactusADM

• • basepeak = yes

454.calculix

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker

481.wrf

• • -QxSSE4.1
  • 
  • OPTIMIZE

  • Code is optimized for Intel(R) processors with support for SSE 4.1 instructions. The resulting code may contain unconditional use of features that are not supported on other processors. This option also enables new optimizations in addition to Intel processor-specific optimizations including advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

    Do not use this option if you are executing a program on a processor that is not an Intel processor. If you use this option on a non-compatible processor to compile the main program (in Fortran) or the function main() in C/C++, the program will display a fatal run-time error if they are executed on unsupported processors.

• • -Qauto-ilp32
  • 
  • OPTIMIZE

  • This option instructs the compiler to analyze and transform the program so that 64-bit pointers are shrunk to 32-bit pointers, and 64-bit longs (on Linux) are shrunk into 32-bit longs wherever it is legal and safe to do so. In order for this option to be effective the compiler must be able to optimize using the -ipo/-Qipo option and must be able to analyze all library/external calls the program makes. This option requires that the size of the program executable never exceeds 2**32 bytes and all data values can be represented within 32 bits. If the program can run correctly in a 32-bit system, these requirements are implicitly satisfied. If the program violates these size restrictions, unpredictable behavior might occur.

• • -Qipo
  • 
  • OPTIMIZE

  • Multi-file ip optimizations that includes:
    - inline function expansion
    - interprocedural constant propogation
    - dead code elimination
    - propagation of function characteristics
    - passing arguments in registers
    - loop-invariant code motion

• • -O3
  • 
  • OPTIMIZE

  • Enables O2 optimizations plus more aggressive optimizations, such as prefetching, scalar replacement, and loop and memory access transformations. Enables optimizations for maximum speed, such as:
    - Loop unrolling, including instruction scheduling
    - Code replication to eliminate branches
    - Padding the size of certain power-of-two arrays to allow more efficient cache use.
    On IA-32 and Intel EM64T processors, when O3 is used with options -ax or -x (Linux) or with options /Qax or /Qx (Windows), the compiler performs more aggressive data dependency analysis than for O2, which may result in longer compilation times.
    The O3 optimizations may not cause higher performance unless loop and memory access transformations take place. The optimizations may slow down code in some cases compared to O2 optimizations.
    The O3 option is recommended for applications that have loops that heavily use floating-point calculations and process large data sets. On IA-32 Windows platforms, -O3 sets the following:

    /GF (/Qvc7 and above), /Gf (/Qvc6 and below), and /Ob2

  • Includes:
    • -GF
    • -Gf
    • -Ob_n
    • -O2
      • -Oi-
      • -Gs
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
      • -O1
        • -Qunroll_n
        • -Oi-
        • -Op-
        • -Oy
        • -Gy
        • -Os
        • -GF
        • -Gf
        • -Ob_n
        • -Og
• • -Qprec-div-
  • 
  • OPTIMIZE
  • (disable/enable[default] -Qprec-div[-])

    This option improves precision of floating-point divides. It has a slight impact on speed.

    With some optimizations, such as -xN and -xB (Linux) or /QxN and /QxB (Windows), the compiler may change floating-point division computations into multiplication by the reciprocal of the denominator. For example, A/B is computed as A * (1/B) to improve the speed of the computation.

    However, sometimes the value produced by this transformation is not as accurate as full IEEE division. When it is important to have fully precise IEEE division, use this option to disable the floating-point division-to-multiplication optimization. The result is more accurate, with some loss of performance.

    If you specify -no-prec-div (Linux and Mac OS) or /Qprec-div- (Windows), it enables optimizations that give slightly less precise results than full IEEE division.

• • -Qopt-prefetch
  • 
  • OPTIMIZE

  • This option enables or disables prefetch insertion optimization. The goal of prefetching is to reduce cache misses by providing hints to the processor about when data should be loaded into the cache.
    On IA-32 architecture and Intel 64 architecture, this option enables prefetching when higher optimization levels are specified.

• • -Qparallel
  • 
  • Yes
  • OPTIMIZE

  • This option tells the auto-parallelizer to generate multithreaded code for loops that can be safely executed in parallel.
    To use this option, you must also specify option O2 or O3.

• • /F1000000000
  • 
  • EXTRA_LDFLAGS

  • set the stack reserve amount specified to the linker