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(gcc-295.info)AMD29K Options

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AMD29K Options
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   These `-m' options are defined for the AMD Am29000:

`-mdw'
     Generate code that assumes the `DW' bit is set, i.e., that byte and
     halfword operations are directly supported by the hardware.  This
     is the default.

`-mndw'
     Generate code that assumes the `DW' bit is not set.

`-mbw'
     Generate code that assumes the system supports byte and halfword
     write operations.  This is the default.

`-mnbw'
     Generate code that assumes the systems does not support byte and
     halfword write operations.  `-mnbw' implies `-mndw'.

`-msmall'
     Use a small memory model that assumes that all function addresses
     are either within a single 256 KB segment or at an absolute
     address of less than 256k.  This allows the `call' instruction to
     be used instead of a `const', `consth', `calli' sequence.

`-mnormal'
     Use the normal memory model: Generate `call' instructions only when
     calling functions in the same file and `calli' instructions
     otherwise.  This works if each file occupies less than 256 KB but
     allows the entire executable to be larger than 256 KB.  This is
     the default.

`-mlarge'
     Always use `calli' instructions.  Specify this option if you expect
     a single file to compile into more than 256 KB of code.

`-m29050'
     Generate code for the Am29050.

`-m29000'
     Generate code for the Am29000.  This is the default.

`-mkernel-registers'
     Generate references to registers `gr64-gr95' instead of to
     registers `gr96-gr127'.  This option can be used when compiling
     kernel code that wants a set of global registers disjoint from
     that used by user-mode code.

     Note that when this option is used, register names in `-f' flags
     must use the normal, user-mode, names.

`-muser-registers'
     Use the normal set of global registers, `gr96-gr127'.  This is the
     default.

`-mstack-check'
`-mno-stack-check'
     Insert (or do not insert) a call to `__msp_check' after each stack
     adjustment.  This is often used for kernel code.

`-mstorem-bug'
`-mno-storem-bug'
     `-mstorem-bug' handles 29k processors which cannot handle the
     separation of a mtsrim insn and a storem instruction (most 29000
     chips to date, but not the 29050).

`-mno-reuse-arg-regs'
`-mreuse-arg-regs'
     `-mno-reuse-arg-regs' tells the compiler to only use incoming
     argument registers for copying out arguments.  This helps detect
     calling a function with fewer arguments than it was declared with.

`-mno-impure-text'
`-mimpure-text'
     `-mimpure-text', used in addition to `-shared', tells the compiler
     to not pass `-assert pure-text' to the linker when linking a
     shared object.

`-msoft-float'
     Generate output containing library calls for floating point.
     *Warning:* the requisite libraries are not part of GCC.  Normally
     the facilities of the machine's usual C compiler are used, but
     this can't be done directly in cross-compilation.  You must make
     your own arrangements to provide suitable library functions for
     cross-compilation.

`-mno-multm'
     Do not generate multm or multmu instructions.  This is useful for
     some embedded systems which do not have trap handlers for these
     instructions.