RealView® Compilation Tools Assembler Guide 5.17.1. FABS, FCPY, and FNEG

Floating-point copy, absolute value, and negate.

These instructions can be scalar, vector, or mixed (see VFP vector and scalar operations).

<op><precision>{cond} Fd, Fm

where:

<op>: must be one of FCPY, FABS, or FNEG.
<precision>: must be either S for single-precision, or D for double-precision.
cond: is an optional condition code (see Condition codes).
Fd: is the VFP register for the result.
Fm: is the VFP register holding the operand.

The precision of Fd and Fm must match the precision specified in <precision>.

The FCPY instruction copies the contents of Fm into Fd.

The FABS instruction takes the contents of Fm, clears the sign bit, and places the result in Fd. This gives the absolute value.

The FNEG instruction takes the contents of Fm, changes the sign bit, and places the result in Fd. This gives the negation of the value.

If the operand is a NaN, the sign bit is determined in each case as above, but no exception is produced.

None of these instructions can produce any exceptions.

    FABSD   d3, d5
    FNEGSMI s15, s15

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