Loop Unrolling with -unroll[n]

The -unroll[n] option is used in the following way:

The Itanium compiler currently uses only n = 0; any other value is NOP.

Benefits and Limitations of Loop Unrolling

The benefits are:

The potential cost: excessive unrolling, or unrolling of very large loops can lead to increased code size.

For more information on how to optimize with -unroll[n], refer to the Intel® Pentium® 4 and Intel® Xeon(TM) Processor Optimization Reference Manual.