as: CRIS-Opts
1
1 9.8.1 Command-line Options
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1
1 The CRIS version of 'as' has these machine-dependent command-line
1 options.
1
1 The format of the generated object files can be either ELF or a.out,
1 specified by the command-line options '--emulation=crisaout' and
1 '--emulation=criself'. The default is ELF (criself), unless 'as' has
1 been configured specifically for a.out by using the configuration name
1 'cris-axis-aout'.
1
1 There are two different link-incompatible ELF object file variants
1 for CRIS, for use in environments where symbols are expected to be
1 prefixed by a leading '_' character and for environments without such a
1 symbol prefix. The variant used for GNU/Linux port has no symbol
1 prefix. Which variant to produce is specified by either of the options
1 '--underscore' and '--no-underscore'. The default is '--underscore'.
1 Since symbols in CRIS a.out objects are expected to have a '_' prefix,
1 specifying '--no-underscore' when generating a.out objects is an error.
1 Besides the object format difference, the effect of this option is to
1 parse register names differently (⇒crisnous). The
1 '--no-underscore' option makes a '$' register prefix mandatory.
1
1 The option '--pic' must be passed to 'as' in order to recognize the
11 symbol syntax used for ELF (SVR4 PIC) position-independent-code (⇒
crispic). This will also affect expansion of instructions. The
1 expansion with '--pic' will use PC-relative rather than (slightly
1 faster) absolute addresses in those expansions. This option is only
1 valid when generating ELF format object files.
1
1 The option '--march=ARCHITECTURE' specifies the recognized
1 instruction set and recognized register names. It also controls the
1 architecture type of the object file. Valid values for ARCHITECTURE
1 are:
1
1 'v0_v10'
1 All instructions and register names for any architecture variant in
1 the set v0...v10 are recognized. This is the default if the target
1 is configured as cris-*.
1
1 'v10'
1 Only instructions and register names for CRIS v10 (as found in
1 ETRAX 100 LX) are recognized. This is the default if the target is
1 configured as crisv10-*.
1
1 'v32'
1 Only instructions and register names for CRIS v32 (code name
1 Guinness) are recognized. This is the default if the target is
1 configured as crisv32-*. This value implies '--no-mul-bug-abort'.
1 (A subsequent '--mul-bug-abort' will turn it back on.)
1
1 'common_v10_v32'
1 Only instructions with register names and addressing modes with
1 opcodes common to the v10 and v32 are recognized.
1
1 When '-N' is specified, 'as' will emit a warning when a 16-bit branch
1 instruction is expanded into a 32-bit multiple-instruction construct
1 (⇒CRIS-Expand).
1
1 Some versions of the CRIS v10, for example in the Etrax 100 LX,
1 contain a bug that causes destabilizing memory accesses when a multiply
1 instruction is executed with certain values in the first operand just
1 before a cache-miss. When the '--mul-bug-abort' command line option is
1 active (the default value), 'as' will refuse to assemble a file
1 containing a multiply instruction at a dangerous offset, one that could
1 be the last on a cache-line, or is in a section with insufficient
1 alignment. This placement checking does not catch any case where the
1 multiply instruction is dangerously placed because it is located in a
1 delay-slot. The '--mul-bug-abort' command line option turns off the
1 checking.
1