Math Functions

Package of useful macros and functions e.g. for fixedpoint operations.

Summary

Math Functions	Package of useful macros and functions e.g.
Fixedpoint Macros
D2_FIX4(x)	Integer to n:4 fixedpoint conversion
D2_INT4(x)	n:4 to integer conversion
D2_FLOOR4(x)	n:4 fixedpoint unsigned floor (round towards -inf)
D2_CEIL4(x)	n:4 fixedpoint unsigned ceil (round towards +inf)
D2_FRAC4(x)	n:4 fixedpoint fractional part only
D2_FIX16(x)	integer to n:16 fixedpoint conversion
D2_INT16(x)	n:16 to integer conversion
D2_FLOOR16(x)	n:16 fixedpoint unsigned floor (round towards -inf)
D2_CEIL16(x)	n:16 fixedpoint unsigned ceil (round towards +inf)
D2_FRAC16(x)	n:16 fixedpoint fractional part only
D2_EPSILON	Smallest representable positive number (all fixedpoint formats)
Math Functions
d2_sqrt	Minimalistic 32->16 bit integer square root (no hw divide/multiply needed) unrolled for speed.
d2_pow2mask	Find next larger power of two minus 1

Integer to n:4 fixedpoint conversion

n:4 to integer conversion

n:4 fixedpoint unsigned floor (round towards -inf)

n:4 fixedpoint unsigned ceil (round towards +inf)

n:4 fixedpoint fractional part only

integer to n:16 fixedpoint conversion

n:16 to integer conversion

n:16 fixedpoint unsigned floor (round towards -inf)

n:16 fixedpoint unsigned ceil (round towards +inf)

n:16 fixedpoint fractional part only

Smallest representable positive number (all fixedpoint formats)

D2_EXTERN d2_s32 d2_sqrt( d2_u32 x )

Minimalistic 32->16 bit integer square root (no hw divide/multiply needed) unrolled for speed.

x	fixedpoint number

the square root of x

D2_EXTERN d2_u32 d2_pow2mask( d2_u32 x )

Find next larger power of two minus 1

E.g. given number x=73 -> next larger power of two is 128, the result is 128 minus 1 = 127 (number with all bits set)

x	positive number

the next larger number of two minus 1 of x