f78 AMD29K Options Contents|Index|Previous|Next

AMD29K options

The following ‘-m’ options are defined for the AMD Am29000.

-mdw

Generate code that assumes the

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

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 25 ffb 6 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:

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 o 6c4 nly use incoming argument registers for copying out arguments. This helps detect calling a function with fewer arguments than those with which it was declared.

-mno-impure-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 GNU CC. 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.