#### 8.29.4 Sparc Machine Directives

The Sparc version of `as` supports the following additional machine directives:

`.align`
  This must be followed by the desired alignment in bytes.

`.common`
  This must be followed by a symbol name, a positive number, and `"bss"`. This behaves somewhat like `.comm`, but the syntax is different.

`.half`
  This is functionally identical to `.short`.

`.nword`
  On the Sparc, the `.nword` directive produces native word sized value, ie. if assembling with -32 it is equivalent to `.word`, if assembling with -64 it is equivalent to `.xword`.

`.proc`
  This directive is ignored. Any text following it on the same line is also ignored.

`.register`
  This directive declares use of a global application or system register. It must be followed by a register name %g2, %g3, %g6 or %g7, comma and the symbol name for that register. If symbol name is `#scratch`, it is a scratch register, if it is `#ignore`, it just suppresses any errors about using undeclared global register, but does not emit any information about it into the object file. This can be useful e.g. if you save the register before use and restore it after.

`.reserve`
  This must be followed by a symbol name, a positive number, and `"bss"`. This behaves somewhat like `.lcomm`, but the syntax is different.

`.seg`
  This must be followed by `"text"`, `"data"`, or `"data1"`. It behaves like `.text`, `.data`, or `.data 1`.

`.skip`
  This is functionally identical to the `.space` directive.

`.word`
  On the Sparc, the `.word` directive produces 32 bit values, instead of the 16 bit values it produces on many other machines.

`.xword`
  On the Sparc V9 processor, the `.xword` directive produces 64 bit values.