CPU2006 Flag Description
Hewlett-Packard Company ProLiant DL380 G5 (2.66 GHz, Intel Xeon processor X5355)

Implicitly Included Flags

This section contains descriptions of flags that were included implicitly by other flags, but which do not have a permanent home at SPEC.

• • -O3
  • 

  • Builds on -01 and -02 optimizations by enabling high-level optimization. This level does not guarantee higher performance unless loop and memory access transformation take place. In conjunction with -QaxK/-QxK and QaxW/QxW, this switch causes the compiler to perform more aggressive data dependency analysis than for -O2. This may result in longer compilation times. 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
• • -GF
  • 

  • This option enables read only string-pooling optimization.

• • -Gf
  • 

  • This option enables read/write string-pooling optimization.

• • -Ob_n
  • 

  • 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.

• • -O2
  • 

  • This is the default level of optimization. Optimizes for speed. The -O2 option includes O1 optimizations and in addition enables inlining of intrinsics and more speed optimizations. On IA-32 Windows platforms, -O2 sets the following:

    /Og, /Oi-, /Os, /Oy, /Ob2, /GF (/Qvc7 and above), /Gf (/Qvc6 and below), /Gs, and /Gy.

  • Includes:
    • -Oi-
    • -Gs
    • -Oy
    • -Gy
    • -Os
    • -GF
    • -Gf
    • -Ob_n
    • -Og
    • -O1
      • -Qunroll_n
      • -Oi-
      • -Op-
      • -Oy
      • -Gy
      • -Os
      • -GF
      • -Gf
      • -Ob_n
      • -Og
• • -Oi-
  • 

  • Disables inline expansion of all intrinsic functions.

• • -Gs
  • 

  • This option disables stack-checking for routines with 4096 bytes of local variables and compiler temporaries.

• • -Oy
  • 

  • Allows use of EBP as a general-purpose register in optimizations.

• • -Gy
  • 

  • This option tells the compiler to separate functions into COMDATs for the linker.

• • -Os
  • 

  • This option enables most speed optimizations, but disables some that increase code size for a small speed benefit.

• • -Og
  • 

  • This option enables global optimizations.

• • -O1
  • 

  • optimize for speed, but disable some optimizations which increase code size for a small speed benefit. Includes inline expansion except for intrinsic functions, global optimizations, string pooling optimizations. On IA-32 Windows platforms, -O1 sets the following:

    /Qunroll0, /Oi-, /Op-, /Oy, /Gy, /Os, /GF (/Qvc7 and above), /Gf (/Qvc6 and below), /Ob2, and /Og

  • Includes:
    • -Qunroll_n
    • -Oi-
    • -Op-
    • -Oy
    • -Gy
    • -Os
    • -GF
    • -Gf
    • -Ob_n
    • -Og
• • -Qunroll_n
  • 

  • Tells the compiler the maximum number of times to unroll loops.

• • -Op-
  • 

  • Disables conformance to the ANSI C and IEEE 754 standards for floating-point arithmetic.

• • -Qipo
  • 

  • 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

• • -QxP
  • 

  • The -QxN and -QxP options target your program to run on Intel Pentium 4 and compatible Intel processors. The resulting code might contain unconditional use of features that are not supported on other processors. Programs, where the function main() is compiled with this option, will detect non compatible processors and generate an error message during execution. This option also enables new optimizations in addition to Intel processor specific optimizations.

    These options also enable advanced data layout and code restructuring optimizations to improve memory accesses for Intel processors.

• • -Qprec-div-
  • 
  • (disable -Qprec-div)

    Allows the compiler to perform optimizations in FP divides that may impact precision while improving speed.

• • -GX
  • 

  • This option enables C++ exception handling.

• • -GR
  • 

  • Enables C++ Run Time Type Information (RTTI).

System and Other Tuning Information

Platform settings

One or more of the following settings may have been set. If so, the "Platform Notes" section of the report will say so; and you can read below to find out more about what these settings mean.

Power Regulator for ProLiant support (Default=HP Dynamic Power Savings Mode)

Values for this BIOS setting can be:

• HP Dynamic Power Savings Mode: Automatically varies processor speed and power usage based on processor utilization. Allows reducing overall power consumption with little or no impact to performance. Does not require OS support.
• HP Static Low Power Mode: Reduces processor speed and power usage. Guarantees a lower maximum power usage for the system. Performance impacts will be greater for environments with higher processor utilization.
• HP Static High Performance Mode: Processors will run in their maximum power/performance state at all times regardless of the OS power managment policy.
• OS Control Mode: Processors will run in their maximum power/ performance state at all times unless the OS enables' a power management policy.

Adjacent Sector Prefetch (Default = Enabled):

This BIOS option allows the enabling/disabling of a processor mechanism to fetch the adjacent cache line within an 128-byte sector that contains the data needed due to a cache line miss.

In some limited cases, setting this option to Disabled may improve performance. In the majority of cases, the default value of Enabled provides better performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

submit= specperl -e "system sprintf qq{start /b /wait /affinity %x %s}, (1<<$SPECCOPYNUM), qq{ $command } "

When running multiple copies of benchmarks, the SPEC config file feature submit is sometimes used to cause individual jobs to be bound to specific processors. This specific submit command is used for Windows. The description of the elements of the command are:

• specperl: SPEC's version of perl.
  • -e: Execute a single line of perl script.
  • system: Execute system command that follows (in this case the sprintf command) and wait for the child process to complete.
  • sprintf: Return formatted string (in this case the formatted start command)
• start
  • /b: Start application without creating a new command prompt window
  • /wait: Start application and wait for it to terminate
  • affinity %x: bind the process to CPUs matching the integer bitmask %x. This is determined by the (1<<$SPECCOPYNUM) value.
  • %s: Program to be started matching the string value %s. The string value is determined by the qq{ $command} value, where $command is the benchmark instance to be started.

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  Flag description origin markings:

  	Indicates that the flag description came from the user flags file.
  	Indicates that the flag description came from the suite-wide flags file.
  	Indicates that the flag description came from a per-benchmark flags file.

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  The flags file that was used to format this result can be browsed at
  http://www.spec.org/cpu2006/flags/hp-ic91-flags.20090715.02.html.

  You can also download the XML flags source by saving the following link:
  http://www.spec.org/cpu2006/flags/hp-ic91-flags.20090715.02.xml.

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  For questions about the meanings of these flags, please contact the tester.
  For other inquiries, please contact webmaster@spec.org
  Copyright 2006-2014 Standard Performance Evaluation Corporation
  Tested with SPEC CPU2006 v1.0.
  Report generated on Tue Jul 22 10:37:03 2014 by SPEC CPU2006 flags formatter v6906.