Sun Studio 12: Debugging a Program With dbx

Platform-Specific Registers

The following tables list platform-specific register names for SPARC architecture, x86 architecture, and AMD64 architecture that can be used in expressions.

SPARC Register Information

The following register information is for [Please define the SPARCsans text entity] architecture.



$g0 through $g7

Global registers 

$o0 through $o7

“out” registers 

$l0 through $l7

“local” registers 

$i0 through $i7

“in” registers 


Frame pointer, equivalent to register $i6 


Stack pointer, equivalent to register $o6 


Y register 


Processor state register 


Window invalid mask register 


Trap base register 


Program counter 


Next program counter 

$f0 through $f31

FPU “f” registers 


FPU status register 


FPU queue 

The $f0f1 $f2f3 ... $f30f31 pairs of floating-point registers are treated as having C “double” type (normally $fN registers are treated as C “float” type). These pairs can also be referred to as $d0 ... $d30.

The following additional registers are available on SPARC V9 and V8+ hardware:

$g0g1 through $g6g7
$o0o1 through $o6o7
$xfsr $tstate $gsr
$f32f33 $f34f35 through $f62f63 ($d32 ... $$d62)

See the SPARC Architecture Reference Manual and the SPARC Assembly Language Reference Manual for more information on SPARC registers and addressing.