6.31.21 Nios II Function Attributes

These function attributes are supported by the Nios II back end:

target ( options )
As discussed in Common Function Attributes , this attribute allows specification of target-specific compilation options.

When compiling for Nios II, the following options are allowed:

custom- insn = N
no-custom- insn
Each ‘ custom- insn = N ’ attribute locally enables use of a custom instruction with encoding N when generating code that uses insn . Similarly, ‘ no-custom- insn ’ locally inhibits use of the custom instruction insn . These target attributes correspond to the -mcustom- insn = N and -mno-custom- insn command-line options, and support the same set of insn keywords. See Nios II Options , for more information.
custom-fpu-cfg= name
This attribute corresponds to the -mcustom-fpu-cfg= name command-line option, to select a predefined set of custom instructions named name . See Nios II Options , for more information.