High-level Language Optimizations

Option

Description

-openmp

Enables the parallelizer to generate multi-threaded code based on the OpenMP directives.
Enables parallel execution on both uni- and multiprocessor systems. Requires -MT and -fpp.

-openmp_
report{0|1|2}
Default:
-openmp_report1

Controls the OpenMP parallelizer's diagnostic levels:
0 - no information
1 - loops, regions, and sections parallelized (default)
2 - same as 1 plus master construct, single construct, etc.

-unroll[n]

n: set maximum number of times to unroll a loop
n omitted: compiler decides whether to perform unrolling or not.
n = 0: disables unroller.
Eliminates some code; hides latencies; can increase code size.
For Itanium-based applications, -unroll[o] is used only for compatibility.

IA-32 applications only

-scalar_rep[-]
 

Enables (default) or disables scalar replacement performed during loop transformations (requires -O3).
Eliminates all loads and stores of that variable
Increases register pressure

-prefetch[-]
 

Enables or disables prefetch insertion (requires -O3).
Reduces the wait time; optimum use is determined empirically.