-xregs=r

Specify register usage.

SPARC: 77/90

r is a comma-separated list that consists of one or more of the following:

[no%]appl, [no%]float.

Where the % is shown, it is a required character.

Example: -xregs=appl,no%float

appl: Allow using the application registers.

On SPARC systems, certain registers are described as application registers. Using these registers can increase performance because fewer load and store instructions are needed. However, such use can conflict with some old library programs written in assembly code.

The set of application registers depends on the SPARC platform:

-xarch=v8 or v8a -- registers g2, g3, and g4

-xarch=v8 or v8a -- registers g2, g3, and g4

-xarch=v8plus or v8plusa -- registers g2, g3, g4, and g5

-xarch=v9 or v9a -- registers g2 and g3

no%appl: Do not use the appl registers.

float: Allow using the floating-point registers as specified in the SPARC ABI.

You can use these registers even if the program contains no floating-point code.

no%float: Do not use the floating-point registers.

With this option, a source program cannot contain any floating-point code.

The default is: -xregs=appl,float.