Non-standard C library math functions are no longer supplied in math.h. They are still provided in the library itself. You can still request the header file from ARM if needed. Contact your supplier.

In RVCT v2.2 changes were made to the behavior of some mathlib functions to bring them in-line with C99. If you relied on the old non-C99 behavior, you could revert the behavior by defining the following at compile time:

#define __ENABLE_LEGACY_MATHLIB

This has been removed in RVCT v4.0 for µVision.