Vector Floating-point Programming
ARM DUI 0068B Copyright © 2000, 2001 ARM Limited. All r ights reserved. 6-19
6.7.3 FCMP
Floating-point co mpare.
FCMP
is always scalar.
Syntax
FCMP{E}<precision>{cond} Fd, Fm
FCMP{E}Z<precision>{cond} Fd
where:
E
is an optional parameter. If
E
is present, an exception is raised if either
operand is any kind of NaN. Otherwise, an exception is raised only if
either operand is a signalling NaN.
Z
is a parameter specifying comparison with zero.
<precision>
must be either
S
for single-precision, or
D
for double-precision.
cond
is an optional condition code (see VFP and condition codes on page6-8).
Fd
is the VFP register holding the first operand.
Fm
is the VFP register holding the second operand. Omit
Fm
for a compare
with zero instruction.
The precision of
Fd
and
Fm
must match the precision specified in
<precision>
.
Usage
The
FCMP
instruction subtracts the value in
Fm
from the value in
Fd
and sets the VFP
condition flags on the result (see VFP and condition codes on page6-8).
Exceptions
FCMP
instructions can produce Invalid Operation exceptions.
Examples
FCMPS s3, s0
FCMPEDNE d5, d13
FCMPZSEQ s2