3.17.25 NS32K Options

These are the -m options defined for the 32000 series. The default values for these options depends on which style of 32000 was selected when the compiler was configured; the defaults for the most common choices are given below.

-m32032

-m32032

Generate output for a 32032. This is the default when the compiler is configured for 32032 and 32016 based systems.

-m32332

-m32332

Generate output for a 32332. This is the default when the compiler is configured for 32332-based systems.

-m32532

-m32532

Generate output for a 32532. This is the default when the compiler is configured for 32532-based systems.

-m32081

Generate output containing 32081 instructions for floating point. This is the default for all systems.

-m32381

Generate output containing 32381 instructions for floating point. This also implies -m32081. The 32381 is only compatible with the 32332 and 32532 cpus. This is the default for the pc532-netbsd configuration.

-mmulti-add

Try and generate multiply-add floating point instructions polyF and dotF. This option is only available if the -m32381 option is in effect. Using these instructions requires changes to register allocation which generally has a negative impact on performance. This option should only be enabled when compiling code particularly likely to make heavy use of multiply-add instructions.

-mnomulti-add

Do not try and generate multiply-add floating point instructions polyF and dotF. This is the default on all platforms.

-msoft-float

Generate output containing library calls for floating point. Warning: the requisite libraries may not be available.

-mieee-compare

-mno-ieee-compare

Control whether or not the compiler uses IEEE floating point comparisons. These handle correctly the case where the result of a comparison is unordered. Warning: the requisite kernel support may not be available.

-mnobitfield

Do not use the bit-field instructions. On some machines it is faster to use shifting and masking operations. This is the default for the pc532.

-mbitfield

Do use the bit-field instructions. This is the default for all platforms except the pc532.

-mrtd

Use a different function-calling convention, in which functions that take a fixed number of arguments return pop their arguments on return with the ret instruction.

This calling convention is incompatible with the one normally used on Unix, so you cannot use it if you need to call libraries compiled with the Unix compiler.

Also, you must provide function prototypes for all functions that take variable numbers of arguments (including printf); otherwise incorrect code will be generated for calls to those functions.

In addition, seriously incorrect code will result if you call a function with too many arguments. (Normally, extra arguments are harmlessly ignored.)

This option takes its name from the 680x0 rtd instruction.

-mregparam

Use a different function-calling convention where the first two arguments are passed in registers.

This calling convention is incompatible with the one normally used on Unix, so you cannot use it if you need to call libraries compiled with the Unix compiler.

-mnoregparam

Do not pass any arguments in registers. This is the default for all targets.

-msb

It is OK to use the sb as an index register which is always loaded with zero. This is the default for the pc532-netbsd target.

-mnosb

The sb register is not available for use or has not been initialized to zero by the run time system. This is the default for all targets except the pc532-netbsd. It is also implied whenever -mhimem or -fpic is set.

-mhimem

Many ns32000 series addressing modes use displacements of up to 512MB. If an address is above 512MB then displacements from zero can not be used. This option causes code to be generated which can be loaded above 512MB. This may be useful for operating systems or ROM code.

-mnohimem

Assume code will be loaded in the first 512MB of virtual address space. This is the default for all platforms.