8 dcfd and dcfdu – ARM VERSION 1.2 User Manual
Page 303
Directives Reference
ARM DUI 0068B
Copyright © 2000, 2001 ARM Limited. All rights reserved.
7-21
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.
DCDFU
is the same, except that the memory alignment is arbitrary.
Syntax
{label} DCFD{U} fpliteral{,fpliteral}...
where:
fpliteral
is a double-precision floating-point literal (see Floating-point literals on
page 3-22).
Usage
The assembler inserts up to three bytes of padding before the first defined number, if
necessary, to achieve 4-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 on page 7-22.
Examples
DCFD 1E308,-4E-100
DCFDU 10000,-.1,3.1E26