This document includes math equations (highlighted in red) which are best viewed with Firefox version 4.0 or higher, or another MathML-aware browser. There is also a PDF version of this document.
libdevice User's Guide (PDF) - CUDA Toolkit v5.5 for POWER8 (older) - Last updated January 10, 2015 - Send Feedback

3.105. __nv_fast_log2f

Prototype:

float @__nv_fast_log2f(float %x) 

Description:

Calculate the fast approximate base 2 logarithm of the input argument x.

Returns:

Returns an approximation to log 2 ( x ) .

Note:

For accuracy information for this function see the CUDA C Programming Guide, Appendix C, Table C-4.

Input and output in the denormal range is flushed to sign preserving 0.0.

Library Availability:

Compute 2.0: Yes

Compute 3.0: Yes

Compute 3.5: Yes


libdevice User's Guide (PDF) - CUDA Toolkit v5.5 for POWER8 (older) - Last updated January 10, 2015 - Send Feedback