Vectorizer Options

Vectorization is an IA-32-specific feature and can be summarized by the command line options described in the following tables. Vectorization depends upon the compiler's ability to disambiguate memory references. Certain options may enable the compiler to do better vectorization. These options can enable other optimizations in addition to vectorization. When a -x{M|K|W} or -ax{M|K|W} is used and -O2 (which is ON by default) is also in effect, the vectorizer is enabled.

-x{M|K|W}

Generate specialized code to run exclusively on the processors supporting the extensions indicated by {M|K|W}. See Exclusive Specialized Code with -x{i|M|K|W} for details.

Note
-xi is not a vectorizer option.

-ax{M|K|W}

Generates, on a single binary, code specialized to the extensions specified by {M|K|W} but also generates generic IA-32 code. The generic code is usually slower. See Specialized Code with -ax{i|M|K|W} for details.

  Note
-axi is not a vectorizer option.

-vec_report
{0|1|2|3|4|5}

Default:
-vec_report1

Controls the diagnostic messages from the vectorizer as follows:
n = 0: no information
n = 1: indicates vectorized /non-vectorizerd integer loops
n = 2: indicates vectorized /non-vectorized integer loops
n = 3: indicates vectorized /non-vectorized integer loops and prohibit data dependence information
n = 4: indicates non-vectorized loops
n = 5: indicates non-vectorized loops and prohibit data dependence information

-vec[-]

Enable (default/disable the vectorizer.