Maximizes speed across the entire program.
IDE Equivalent
NoneArchitectures
IA-32, Intel® 64 architectures
Syntax
Linux and Mac OS X: | -fast |
Windows: | /fast |
Arguments
None
Default
OFF |
The optimizations that maximize speed are not enabled. |
Description
This option maximizes speed across the entire program.
It sets the following options:
On Mac OS* X systems: -ipo, -mdynamic-no-pic, -O3, -no-prec-div, and -xHost
On Windows* systems: /O3, /Qipo, /Qprec-div-, and /QxHost
On Linux* systems: -ipo, -O3, -no-prec-div, -static, and -xHost
When option fast is specified, you can override the -xHost or /QxHost setting by specifying a different processor-specific -x or /Qx option on the command line. However, the last option specified on the command line takes precedence.
For example, if you specify -fast -xSSE3 (Linux) or /fast /QxSSE3 (Windows), option -xSSE3 or /QxSSE3 takes effect. However, if you specify -xSSE3 -fast (Linux) or /QxSSE3 /fast (Windows), option -xHost or /QxHost takes effect.
For implications on non-Intel processors, refer to the xHost documentation.
Note
Option fast sets some aggressive optimizations that may not be appropriate for all applications. The resulting executable may not run on processor types different from the one on which you compile. You should make sure that you understand the individual optimization options that are enabled by option fast.
Optimization Notice |
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Intel’s compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice. Notice revision #20110804 |
Alternate Options
None