Convert to negative float number

[jpeeters19]

is there an easy way to convert a float variable from positive to negative?
I am now using the following code:
floatNumber = 0 - FloatNumber

[top204]

MyFloat = -MyFloat

The compiler uses a highly optimised method of changing a floating point variable's sign. For example, with a 14-bit core device it uses the assembler code:

Code Select Expand

    movlw 128
    xorwf MyFloatH,F

With an 18F device it uses:

Code Select Expand

    btg MyFloatH,7,0