Floating-point literals

ARM Compiler toolchain v4.1 for µVision Using the Assembler

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Floating-point literals

Floating-point literals can take any of the following forms:

{-}digits  E{-}digits  {-}{digits}.digits {-}{digits}.digitsE{-}digits 0xhexdigits &hexdigits 0f_hexdigits 0d_hexdigits

where:

digits: Are sequences of characters using only the digits 0 to 9. You can write E in uppercase or lowercase. These forms correspond to normal floating-point notation.
hexdigits: Are sequences of characters using only the digits 0 to 9 and the letters A to F or a to f. These forms correspond to the internal representation of the numbers in the computer. Use these forms to enter infinities and NaNs, or if you want to be sure of the exact bit patterns you are using.

The 0x and & forms allow the floating-point bit pattern to be specified by any number of hex digits.

The 0f_ form requires the floating-point bit pattern to be specified by exactly 8 hex digits.

The 0d_ form requires the floating-point bit pattern to be specified by exactly 16 hex digits.

The range for single-precision floating-point values is:

maximum 3.40282347e+38
minimum 1.17549435e-38.

The range for double-precision floating-point values is:

maximum 1.79769313486231571e+308
minimum 2.22507385850720138e-308.

Floating-point numbers are only available if your system has VFP.

Examples

    DCFD    1E308,-4E-100
    DCFS    1.0
    DCFS    0.02
    DCFD    3.725e15
    DCFS    0x7FC00000              ; Quiet NaN
    DCFD    &FFF0000000000000       ; Minus infinity

Floating-point literals

Examples

See also