If your target board does not support the MIPS floating point
coprocessor, you should use the command ‘set mipsfpu none’ (if you
need this, you may wish to put the command in your gdb init
file). This tells gdb how to find the return value of
functions which return floating point values. It also allows
gdb to avoid saving the floating point registers when calling
functions on the board. If you are using a floating point coprocessor
with only single precision floating point support, as on the r4650
processor, use the command ‘set mipsfpu single’. The default
double precision floating point coprocessor may be selected using
‘set mipsfpu double’.
In previous versions the only choices were double precision or no
floating point, so ‘set mipsfpu on’ will select double precision
and ‘set mipsfpu off’ will select no floating point.
As usual, you can inquire about the mipsfpu variable with
‘show mipsfpu’.