Defines the maximum allowable relative error for math library function results.
IDE Equivalent
NoneArchitectures
IA-32, Intel® 64 architectures
Syntax
Linux and Mac OS X: | -fimf-max-error=ulps[:funclist] |
Windows: | /Qimf-max-error:ulps[:funclist] |
Arguments
ulps |
Is a positive, floating-point number indicating the maximum allowable relative error the compiler should use. The format for the number is [digits] [.digits] [ { e | E }[sign]digits] |
funclist |
Is an optional list of one or more math library functions to which the attribute should be applied. If you specify more than one function, they must be separated with commas. |
Default
OFF |
The compiler uses default heuristics when calling math library functions. |
Description
This option defines the maximum allowable relative error, measured in ulps, for math library function results.
This option can improve run-time performance, but it may decrease the accuracy of results.
If option -fimf-precision (Linux* OS and Mac OS* X) or /Qimf-precision (Windows* OS), or option -fimf-max-error (Linux* OS and Mac OS* X) or /Qimf-max-error (Windows* OS), or option -fimf-accuracy-bits (Linux OS and Mac OS* X) or /Qimf-accuracy-bits (Windows OS) is specified, the default value for max-error is determined by that option. If one or more of these options are specified, the default value for max-error is determined by the last one specified on the command line.
If none of these options are specified, the default value for max-error is determined by the setting specified for option-[no-]fast-transcendentals (Linux OS and Mac OS X) or /Qfast-transcendentals[-] (Windows OS). If that option also has not been specified, the default value is determined by the setting of option -fp-model (Linux OS and Mac OS X) or /fp (Windows OS).
Note
Many routines in libraries libm (Math Library) and svml (Short Vector Math Library) are more highly optimized for Intel® microprocessors than for non-Intel microprocessors.
Alternate Options
None