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8.5.1 Command-line Options

The CRIS version of as has these machine-dependent command-line options.

The format of the generated object files can be either ELF or a.out, specified by the command-line options `--emulation=crisaout' and `--emulation=criself'. The default is ELF (criself), unless as has been configured specifically for a.out by using the configuration name cris-axis-aout.

There are two different link-incompatible ELF object file variants for CRIS, for use in environments where symbols are expected to be prefixed by a leading `_' character and for environments without such a symbol prefix. The variant used for GNU/Linux port has no symbol prefix. Which variant to produce is specified by either of the options `--underscore' and `--no-underscore'. The default is `--underscore'. Since symbols in CRIS a.out objects are expected to have a `_' prefix, specifying `--no-underscore' when generating a.out objects is an error. Besides the object format difference, the effect of this option is to parse register names differently (see crisnous). The `--no-underscore' option makes a `$' register prefix mandatory.

The option `--pic' must be passed to as in order to recognize the symbol syntax used for ELF (SVR4 PIC) position-independent-code (see crispic). This will also affect expansion of instructions. The expansion with `--pic' will use PC-relative rather than (slightly faster) absolute addresses in those expansions.

When `-N' is specified, as will emit a warning when a 16-bit branch instruction is expanded into a 32-bit multiple-instruction construct (see section 8.5.2 Instruction expansion).


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