log - Logarithm base 2

log     dest, src{ .x | .y | .z | .w }

Name	Registers
dest	An output register or temporary register.
src	A temporary register, input register, or floating-point constant register.

Only one component must be specified for src.

Calculates a binary logarithm.

If the result of the operation is positive or negative infinity, NaN may be output.
Use the cmp instruction if you need to distinguish between NaN and positive or negative infinity.

tmp = src { .x | .y | .z | .w }
dest.x = log2 ( tmp )
dest.y = log2 ( tmp )
dest.z = log2 ( tmp )
dest.w = log2 ( tmp )

log     r0,     c1.x

	1	2	3	4	5
log	read	LOG		post	write

2011/12/20

Initial version.