_may_i_use_cpu_feature

Syntax

Arguments

Description

This intrinsic will query the processor on which it is running to check to see if the given feature is (or features are) available. This check is dynamically performed at the point in the source where it is called. For example:

if (_may_i_use_cpu_feature(_FEATURE_SSE4_2)) {
                        Use SSE4.2 intrinsics;
} Else {
                        Use generic code;
}

The _may_i_use_feature intrinsic, in this case, will dynamically check to see if the code is being executed on a processor that supports SSE4.2, and return true if it is supported (false, otherwise). The _may_i_use_feature also accepts multiple features within a single argument, for example:

if (_may_i_use_cpu_feature(_FEATURE_SSE |
                                        _FEATURE_SSE2 |
                                        _FEATURE_SSE3 |
                                        _FEATURE_SSSE3 |
                                        _FEATURE_MOVBE) &&
                                        !_may_i_use_cpu_feature(_FEATURE_SSE4_1)) {
printf(“\nYou are running on an Atom processor.”\n”);
}

This intrinsic does not perform processor vendor checks that other features do (-m <cpu> type option).

Returns

Result of the feature query, true or false (1 or 0) for whether the set of features is available on the machine on which the intrinsic is executed.