New Options in Version 6.0

Option

Description Default

-c99

Enable C99 support for C programs

OFF

-falias

Assume aliasing in program.

ON

-fno-alias

Assume no aliasing in program.

OFF

-ffnalias

Assume aliasing within functions.

ON

-fno-fnalias

Assume no aliasing within functions, but assume aliasing across calls.

OFF

-fcode-asm

Produce assembly file with optional code annotations.

OFF

-fsource-asm

Produce assembly file with optional source annotations.

OFF

-fverbose-asm

Produce assembly file with compiler comments.

ON

-fnverbose-asm

Produce assembly file with no compiler comments.

OFF

-ftz
Itanium-based systems only

Flushes denormal results to zero.

OFF

-IPF_fma[-]
Itanium-based
systems only

Enable [disable] the combining of floating-point multiplies and add/subtract operations.

OFF

-IPF_fltacc[-]
Itanium-based
systems only

Enable [disable] optimizations that affect floating point accuracy.

OFF

-IPF_flt_eval_method0
Itanium-based
systems only

Floating-point operands evaluated to the precision indicated by program.

OFF

-IPF_fp_speculationmode
Itanium-based
systems only

Enable floating-point speculations with the following mode conditions:

  • fast - speculate floating-point operations
  • safe - speculate only when safe
  • strict - same as off
  • off - disables speculation of floating-point operations

OFF

-ivdep_parallel
Itanium-based systems only

This option indicates there is absolutely no loop-carried memory dependency in the loop where IVDEP directive is specified.

OFF

-openmpP

Same as openmp (parallel).

OFF

-openmpS

Enables the user to compile OpenMP* programs in sequential mode. The openmp directives are ignored, and a stub OpenMP library is linked (sequential).

OFF

-opt_report

Generates an optimization report directed to stderr, unless -opt_report_file is specified.

OFF

-opt_report_filefilename Specifies the filename for the optimization report. It is not necessary to invoke -opt_report when this option is specified. OFF
-opt_report_level[level] Specifies the verbosity level of the output. Valid level arguments:
  • min
  • med
  • max
If a level is not specified, min is used by default.
OFF
-opt_report_phasephase Specifies the compilation phase for which reports are generated. The option can be used multiple times in the same compilation to get output from multiple phases.
Valid phase arguments:
  • ipo: Interprocedural Optimizer
  • hlo: High Level Optimizer
  • ilo: Intermediate Language Scalar Optimizer
  • ecg: Electron Code Generator
  • omp: OpenMP*
  • all: All phases
OFF
-opt_report_routine[substring] Specifies a routine substring. Reports from all routines with names that include substring as part of the name are generated. By default, reports for all routines are generated. OFF
-opt_report_help Displays all possible settings for -opt_report_phase. No compilation is performed. OFF

-parallel

Detects parallel loops capable of being executed safely in parallel and automatically generates multithreaded code for these loops. OFF

-par_report{0|1|2|3}

Controls the auto-parallelizer's diagnostic levels 0, 1, 2, or 3 as follows:
  • -par_report0: no diagnostic information is displayed.
  • -par_report1: indicates loops successfully auto-parallelized (default).
  • -par_report2: loops successfully and unsccessfully auto-parallelized.
  • -par_report3: same as 2 plus additional information about any proven or assumed dependences inhibiting auto-parallelization.
OFF

-par_thresholdn

Sets a threshold for the auto-parallelization of loops based on the probability of profitable execution of the loop in parallel, n=0 to 100. This option is used for loops whose computation work volume cannot be determined at compile time.
  • -par_threshold0: loops get auto-parallelized regardless of computation work volume.
  • -par_threshold100: loops get auto-parallelized only if profitable parallel execution is almost certain.
OFF
-x[type] All source files found subsequent to -x[type] will be recognized as one of the following types:
  • c: C source file
  • c++: C++ source file
  • c-header: C header file
  • cpp-output: C preprocessed file
  • assembler: Assembly file
  • assembler-with-cpp: Assembly file that needs to be preprocessed.
  • none: Disable recognition and revert to file extension.
OFF