-xregs=r (Sun WorkShop Compiler C 5.0 User's Guide)

Sun WorkShop Compiler C 5.0 User's Guide

`-xregs=r`

(SPARC) Specifies the usage of registers for the generated code.

r is a comma-separated list that consists of one or more of the following: [no%]appl, [no%]float.

Example: -xregs=appl,no%float

Table 2-4 The -xregs Values


Value	Meaning
appl	Allows the use of the following registers: g2, g3, g4 (v8, v8a) g2, g3, g4, g5 (v8plus, v8plusa) g2, g3 (v9, v9a) In the SPARC ABI, these 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.
no%appl	Does not use the `appl` registers.
float	Allows 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	Does not use the floating-point registers. With this option, a source program cannot contain any floating-point code.

The default is -xregs=appl,float.