Reading the FTZ and DAZ Flags

This code sample demonstrates how to use compiler macros to read the FTZ and DAZ flags in the MXCSR control register.

See Also

-ftz, /Qftz compiler option-ftz, /Qftz compiler option

/*

 * [Description]

 * This code sample demonstrates how to use the  

 * _MM_GET_FLUSH_ZERO_MODE() and _MM_GET_DENORMALS_ZERO_MODE()

 * macros to read the FTZ and DAZ flags in the control register.

 *

 * [Compile]

 * icc ftz_daz.c (linux) | icl ftz_daz.c (windows)

 *

 * Turning off optimization changes the state of the registers

 * icc -O0 ftz_daz.c (linux) | icl /Od ftz_daz.c (windows)

 *

 * [Output]

 * Shows the state of the FTZ and DAZ registers.

 */

#include <stdio.h>

#include <xmmintrin.h>

#include <pmmintrin.h>

int main(void){

/* Test the control register for flush to zero mode */

if ( _MM_GET_FLUSH_ZERO_MODE() )

         printf("FTZ is set.\n");

    else

         printf("FTZ is not set.\n");

/* Test the control register for denormals mode */

if ( _MM_GET_DENORMALS_ZERO_MODE() )

         printf("DAZ is set.\n");

    else

         printf("DAZ is not set.\n");

return (0);

}