#### 9.9.1 D10V Options

The Mitsubishi D10V version of `as` has a few machine dependent options.

‘`-O`’
  The D10V can often execute two sub-instructions in parallel. When this option is used, `as` will attempt to optimize its output by detecting when instructions can be executed in parallel.
‘`--nowarnswap`’
  To optimize execution performance, `as` will sometimes swap the order of instructions. Normally this generates a warning. When this option is used, no warning will be generated when instructions are swapped.
‘`--gstabs-packing`’
‘`--no-gstabs-packing`’
  `as` packs adjacent short instructions into a single packed instruction. ‘`--no-gstabs-packing`’ turns instruction packing off if ‘`--gstabs`’ is specified as well; ‘`--gstabs-packing`’ (the default) turns instruction packing on even when ‘`--gstabs`’ is specified.