Chapter 37.

SPARC Dependent Features

37.1. Options

The SPARC chip family includes several successive levels, using the same core instruction set, but

including a few additional instructions at each level. There are exceptions to this however. For details

on what instructions each variant supports, please see the chip's architecture reference manual.

By default,

as

assumes the core instruction set (SPARC v6), but "bumps" the architecture level as

needed: it switches to successively higher architectures as it encounters instructions that only exist in

the higher levels.

If not configured for SPARC v9 (

sparc64 * *

) GAS will not bump passed sparclite by default, an

option must be passed to enable the v9 instructions.

GAS treats sparclite as being compatible with v8, unless an architecture is explicitly requested.

SPARC v9 is always incompatible with sparclite.

 Av6 |  Av7 |  Av8 |  Asparclet |  Asparclite

 Av8plus |  Av8plusa |  Av9 |  Av9a

Use one of the

 A

options to select one of the SPARC architectures explicitly. If you select an

architecture explicitly,

as

reports a fatal error if it encounters an instruction or feature requiring

an incompatible or higher level.

 Av8plus

and

 Av8plusa

select a 32 bit environment.

 Av9

and

 Av9a

select a 64 bit environment and are not available unless GAS is explicitly

configured with 64 bit environment support.

 Av8plusa

and

 Av9a

enable the SPARC V9 instruction set with UltraSPARC extensions.

 xarch=v8plus |  xarch=v8plusa

For compatibility with the Solaris v9 assembler. These options are equivalent to  Av8plus and

 Av8plusa, respectively.

 bump

Warn whenever it is necessary to switch to another level. If an architecture level is explicitly

requested, GAS will not issue warnings until that level is reached, and will then bump the level

as required (except between incompatible levels).

 32 |  64

Select the word size, either 32 bits or 64 bits. These options are only available with the ELF

object file format, and require that the necessary BFD support has been included.

37.2. Enforcing aligned data

SPARC GAS normally permits data to be misaligned. For example, it permits the

.long

pseudo op

to be used on a byte boundary. However, the native SunOS and Solaris assemblers issue an error when

they see misaligned data.