7.3.8. DCFD and DCFDU

The DCFD directive allocates memory for word-aligned double-precision floating-point numbers, and defines the initial runtime contents of the memory. Double-precision numbers occupy two words and must be word aligned to be used in arithmetic operations.

DCFDU is the same, except that the memory alignment is arbitrary.


{label} DCFD{U} fpliteral{,fpliteral}...



is a double-precision floating-point literal (see Floating‑point literals).


The assembler inserts up to three bytes of padding before the first defined number, if necessary, to achieve four-byte alignment.

Use DCFDU if you do not require alignment.

The word order used when converting fpliteral to internal form is controlled by the floating-point architecture selected. You cannot use DCFD or DCFDU if you select the --fpu none option.

The range for double-precision numbers is:

  • maximum 1.79769313486231571e+308

  • minimum 2.22507385850720138e-308.

See also DCFS and DCFSU.


        DCFD    1E308,-4E-100
        DCFDU   10000,-.1,3.1E26
Copyright © 2002-2010 ARM. All rights reserved.ARM DUI 0204J