Instructs the compiler to use run-time dispatch in calls to math functions.
Linux: | -fimf-force-dynamic-target[=funclist] |
macOS: | -fimf-force-dynamic-target[=funclist] |
Windows: | /Qimf-force-dynamic-target[:funclist] |
funclist |
Is an optional list of one or more math library functions to which the attribute should be applied. Do not specify the standard Fortran name of the math function; you must specify the actual math library name. If you specify more than one function, they must be separated with commas. Precision-specific variants like sin and sinf are considered different functions, so you would need to use -fimf-dynamic-target=sin,sinf (or /Qimf-dynamic-target:sin,sinf) to specify run-time dispatch for both the single-precision and double-precision sine functions. You also can specify the symbol /f to denote single-precision divides, symbol / to denote double-precision divides, symbol /l to denote extended-precision divides, and symbol /q to denote quad-precision divides. For example, you can specify -fimf-dynamic-target=/ or /Qimf-dynamic-target:/. |
OFF |
Run-time dispatch is not forced in math libraries calls. The compiler can choose to call a CPU-specific version of a math function if one is available. |
This option instructs the compiler to use run-time dispatch in calls to math functions. When this option set to ON, it lets you force run-time dispatch in math libraries calls.
By default, when this option is set to OFF, the compiler often optimizes math library calls using the target CPU architecture-specific information available at compile time through the [Q]x and arch compiler options.
If you want to target multiple CPU families with a single application or you prefer to choose a target CPU at run time, you can force run-time dispatch in math libraries by using this option.
The standard Fortran names for the various math intrinsic functions do not match the math library names of the math intrinsic functions. You must find the actual math library name that is generated for the relevant Fortran math intrinsic.
One way to do this is to generate assembly code by using options /Fa or /S on Windows, or option -S on Linux. The assembly code will show the actual math library name.
For example, if you create a program that contains a call to SIN(x) where x is declared as REAL(KIND=4) and then use option /S on Windows to produce assembly code for the program, the assembly code will show a call to sinf.
Therefore, to use run-time dispatch in calls to the single-precision sine function, you would specify -fimf-force-dynamic-target=sinf (or /Qimf-force-dynamic-target:sinf).
Product and Performance Information |
|---|
Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex. Notice revision #20201201 |
None