# Setting the FTZ and DAZ Flags

In Intel® processors, the flush-to-zero (`FTZ`) and denormals-are-zero (`DAZ`) flags in the MXCSR register are used to control floating-point calculations. Intel® Streaming SIMD Extensions (Intel® SSE) and Intel® Advanced Vector Extensions (Intel® AVX) instructions, including scalar and vector instructions, benefit from enabling the `FTZ` and `DAZ` flags. Floating-point computations using the Intel® SSE and Intel® AVX instructions are accelerated when the `FTZ` and `DAZ` flags are enabled. This improves the application's performance.

Manually set the flags with the following macros:

Feature | Examples
--- | ---
Enable `FTZ` | `_MM_SET_FLUSH_ZERO_MODE(_MM_FLUSH_ZERO_ON)`
Enable `DAZ` | `_MM_SET_DENORMALS_ZERO_MODE(_MM_DENORMALS_ZERO_ON)`

The prototypes for these macros are in xmmintrin.h (`FTZ`) and pmmintrin.h (`DAZ`).

Parent topic: Understanding Floating-Point Operations