CPU2006 Flag Description
Sun Microsystems Ultra Enterprise 2

Compilers: Sun Studio 11

Operating systems: Solaris 10

Last updated: 18-Jul-2006 cds

The text for many of the descriptions below was taken from the Sun Studio 11 Compiler Documentation, which is copyright © 2005 Sun Microsystems, Inc. The original documentation can be found at docs.sun.com.

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.

• • -D__MATHERR_ERRNO_DONTCARE
  • 
  • sun_cc,sun_CC

  • Allows the compiler to assume that your code does not rely on setting of the errno variable.

• • -dalign
  • 

  • Assume data is naturally aligned.

• • -fns
  • 

  • Selects faster (but nonstandard) handling of floating point arithmetic exceptions and gradual underflow.

• • -fsimple=2
  • 

  • Controls simplifying assumptions for floating point arithmetic:

    • -fsimple=0 permits no simplifying assumptions. Preserves strict IEEE 754 conformance.
    • -fsimple=1 allows the optimizer to assume:
      • The IEEE 754 default rounding/trapping modes do not change after process initialization.
      • Computations producing no visible result other than potential floating-point exceptions may be deleted.
      • Computations with Infinity or NaNs as operands need not propagate NaNs to their results. For example, x*0 may be replaced by 0.
      • Computations do not depend on sign of zero.
    • -fsimple=2 permits more aggressive floating point optimizations that may cause programs to produce different numeric results due to changes in rounding. Even with -fsimple=2, the optimizer still is not permitted to introduce a floating point exception in a program that otherwise produces none.
• • -fsingle
  • 
  • sun_cc

  • Evaluate float expressions as single precision.

• • -ftrap=%none
  • 

  • Turns off all IEEE 754 trapping modes.

• • -xalias_level=basic
  • 
  • sun_cc

  • Allows the compiler to perform type-based alias analysis at the specified alias level:

    • basic assume that memory references that involve different C basic types do not alias each other.
    • std assume aliasing rules described in the ISO 1999 C standard.
    • strong in addition to the restrictions at the std level, assume that pointers of type char * are used only to access an object of type char; and assume that there are no interior pointers.
• • -xbuiltin=%all
  • 
  • sun_cc,sun_CC

  • Substitute intrinsic functions or inline system functions where profitable for performance.

• • -xdepend
  • 

  • Analyze loops for inter-iteration data dependencies, and do loop restructuring.

• • -xlibmil
  • 

  • Use inline expansion for math library, libm.

• • -xO5
  • 

  • Specify optimization level n:

    • -xO1 does only basic local optimizations (peephole.)
    • -xO2 Do basic local and global optimizations, such as induction variable elimination, common subexpression elimination, constant propogation, register allocation, and basic block merging.
    • -xO3 Add global optimizations at the function level, loop unrolling, and software pipelining.
    • -xO4 Adds automatic inlining of functions in the same file.
    • -xO5 Uses optmization algorithms that may take significantly more compilation time or that do not have as high a probability of improving execution time, such as speculative code motion.
• • -xprefetch=auto,explicit
  • 

  • Allow generation of prefetch instructions. -xprefetch=yes and -xprefetch are synonyms for -xprefetch=auto,explicit.

• • -xtarget=native
  • 

  • Selects options appropriate for the system where the compile is taking place, including architecture, chip, and cache sizes. (These can also be controlled separately, via -xarch, -xchip, and -xcache, respectively.)

• • -xlibmopt
  • 
  • sun_CC,sun_f90

  • Select the optimized math library.

System and Other Tuning Information

Platform settings

One or more of the following settings may have been applied to the testbed. 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.

autoup=<n> (Unix)
When the file system flush daemon fsflush runs, it writes to disk all modified file buffers that are more than n seconds old.

cpu_bringup_set=<n> (Unix /etc/system)
Specifies which processors are enabled at boot time. <n> represents a bitmap of the processors to be brought online.

disablecomponent (System Management Services)
This command can be used prior to booting the system for a 1-cpu test. The tester uses disablecomponent to add all other CPUs to the "blacklist", which is a list of components that cannot be used at boot time.

LD_LIBRARY_PATH=<directories> (linker)
LD_LIBRARY_PATH controls the search order for both the compile-time and run-time linkers. Usually, it can be defaulted; but testers may sometimes choose to explicitly set it (as documented in the notes in the submission), in order to ensure that the correct versions of libraries are picked up.

PARALLEL=<n> (Unix)
If programs have been compiled with -xautopar, this environment variable can be set to the number of processors that programs should use.

STACKSIZE=<n> (Unix)
Set the size of the stack (temporary storage area) for each slave thread of a multithreaded program.

submit=echo 'pbind -b...' > dobmk; sh dobmk (SPEC tools, Unix)
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. If so, the specific command may be found in the config file; here is a brief guide to understanding that command:

• submit= causes the SPEC tools to use this line when submitting jobs.
• echo ...> dobmk causes the generated commands to be written to a file, namely dobmk.
• pbind -b causes this copy's processes to be bound to the CPU specified by the expression that follows it. See the config file used in the submission for the exact syntax, which tends to be cumbersome because of the need to carefully quote parts of the expression. When all expressions are evaluated, each core ends up with exactly one copy of each benchmark. The pbind expression may include:
  • $SPECUSERNUM: the SPEC tools-assigned number for this copy of the benchmark.
  • psrinfo: find out what processors are available
  • grep on-line: search the psrinfo output for information regarding on-line cpus
  • expr: Calculate simple arithmetic expressions. For example, the effect of binding jobs to a (quote-resolved) expression such as:
    expr ( $SPECUSERNUM / 4 ) * 8 + ($SPECUSERNUM % 4 ) )
    would be to send the jobs to processors whose numbers are:
    0,1,2,3, 8,9,10,11, 16,17,18,19 ...
  • awk...print \$1: Pick out the line corresponding to this copy of the benchmark and use the CPU number mentioned at the start of this line.
• sh dobmk actually runs the benchmark.

tune_t_fsflushr=<n> (Unix)
Controls the number of seconds between runs of the file system flush daemon, fsflush.

ulimit -s <n> (Unix)
Sets the stack size to n kbytes, or "unlimited" to allow the stack size to grow without limit.

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.

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 v89.
Report generated on Tue Jul 22 10:01:52 2014 by SPEC CPU2006 flags formatter v6906.