-march=arch- Generate code for a specific M680x0 or ColdFire instruction set
architecture. Permissible values of arch for M680x0
architectures are: `68000', `68010', `68020',
`68030', `68040', `68060' and `cpu32'. ColdFire
architectures are selected according to Freescale's ISA classification
and the permissible values are: `isaa', `isaaplus',
`isab' and `isac'.
gcc defines a macro `__mcfarch__' whenever it is generating
code for a ColdFire target. The arch in this macro is one of the
-march arguments given above.
When used together, -march and -mtune select code
that runs on a family of similar processors but that is optimized
for a particular microarchitecture.
-mcpu=cpu- Generate code for a specific M680x0 or ColdFire processor.
The M680x0 cpus are: `68000', `68010', `68020',
`68030', `68040', `68060', `68302', `68332'
and `cpu32'. The ColdFire cpus are given by the table
below, which also classifies the CPUs into families:
| Family | `-mcpu' arguments
|
| `51qe' | `51qe'
|
| `5206' | `5202' `5204' `5206'
|
| `5206e' | `5206e'
|
| `5208' | `5207' `5208'
|
| `5211a' | `5210a' `5211a'
|
| `5213' | `5211' `5212' `5213'
|
| `5216' | `5214' `5216'
|
| `52235' | `52230' `52231' `52232' `52233' `52234' `52235'
|
| `5225' | `5224' `5225'
|
| `5235' | `5232' `5233' `5234' `5235' `523x'
|
| `5249' | `5249'
|
| `5250' | `5250'
|
| `5271' | `5270' `5271'
|
| `5272' | `5272'
|
| `5275' | `5274' `5275'
|
| `5282' | `5280' `5281' `5282' `528x'
|
| `5307' | `5307'
|
| `5329' | `5327' `5328' `5329' `532x'
|
| `5373' | `5372' `5373' `537x'
|
| `5407' | `5407'
|
| `5475' | `5470' `5471' `5472' `5473' `5474' `5475' `547x' `5480' `5481' `5482' `5483' `5484' `5485'
|
-mcpu=cpu overrides -march=arch if
arch is compatible with cpu. Other combinations of
-mcpu and -march are rejected.
gcc defines the macro `__mcf_cpu_cpu' when ColdFire target
cpu is selected. It also defines `__mcf_family_family',
where the value of family is given by the table above.
-mtune=tune- Tune the code for a particular microarchitecture, within the
constraints set by -march and -mcpu.
The M680x0 microarchitectures are: `68000', `68010',
`68020', `68030', `68040', `68060'
and `cpu32'. The ColdFire microarchitectures
are: `cfv1', `cfv2', `cfv3', `cfv4' and `cfv4e'.
You can also use -mtune=68020-40 for code that needs
to run relatively well on 68020, 68030 and 68040 targets.
-mtune=68020-60 is similar but includes 68060 targets
as well. These two options select the same tuning decisions as
-m68020-40 and -m68020-60 respectively.
gcc defines the macros `__mcarch' and `__mcarch__'
when tuning for 680x0 architecture arch. It also defines
`mcarch' unless either -ansi or a non-GNU -std
option is used. If gcc is tuning for a range of architectures,
as selected by -mtune=68020-40 or -mtune=68020-60,
it defines the macros for every architecture in the range.
gcc also defines the macro `__muarch__' when tuning for
ColdFire microarchitecture uarch, where uarch is one
of the arguments given above.
-m68000-mc68000- Generate output for a 68000. This is the default
when the compiler is configured for 68000-based systems.
It is equivalent to -march=68000.
Use this option for microcontrollers with a 68000 or EC000 core,
including the 68008, 68302, 68306, 68307, 68322, 68328 and 68356.
-m68010- Generate output for a 68010. This is the default
when the compiler is configured for 68010-based systems.
It is equivalent to -march=68010.
-m68020-mc68020- Generate output for a 68020. This is the default
when the compiler is configured for 68020-based systems.
It is equivalent to -march=68020.
-m68030- Generate output for a 68030. This is the default when the compiler is
configured for 68030-based systems. It is equivalent to
-march=68030.
-m68040- Generate output for a 68040. This is the default when the compiler is
configured for 68040-based systems. It is equivalent to
-march=68040.
This option inhibits the use of 68881/68882 instructions that have to be
emulated by software on the 68040. Use this option if your 68040 does not
have code to emulate those instructions.
-m68060- Generate output for a 68060. This is the default when the compiler is
configured for 68060-based systems. It is equivalent to
-march=68060.
This option inhibits the use of 68020 and 68881/68882 instructions that
have to be emulated by software on the 68060. Use this option if your 68060
does not have code to emulate those instructions.
-mcpu32- Generate output for a CPU32. This is the default
when the compiler is configured for CPU32-based systems.
It is equivalent to -march=cpu32.
Use this option for microcontrollers with a
CPU32 or CPU32+ core, including the 68330, 68331, 68332, 68333, 68334,
68336, 68340, 68341, 68349 and 68360.
-m5200- Generate output for a 520X ColdFire CPU. This is the default
when the compiler is configured for 520X-based systems.
It is equivalent to -mcpu=5206, and is now deprecated
in favor of that option.
Use this option for microcontroller with a 5200 core, including
the MCF5202, MCF5203, MCF5204 and MCF5206.
-m5206e- Generate output for a 5206e ColdFire CPU. The option is now
deprecated in favor of the equivalent -mcpu=5206e.
-m528x- Generate output for a member of the ColdFire 528X family.
The option is now deprecated in favor of the equivalent
-mcpu=528x.
-m5307- Generate output for a ColdFire 5307 CPU. The option is now deprecated
in favor of the equivalent -mcpu=5307.
-m5407- Generate output for a ColdFire 5407 CPU. The option is now deprecated
in favor of the equivalent -mcpu=5407.
-mcfv4e- Generate output for a ColdFire V4e family CPU (e.g. 547x/548x).
This includes use of hardware floating point instructions.
The option is equivalent to -mcpu=547x, and is now
deprecated in favor of that option.
-m68020-40- Generate output for a 68040, without using any of the new instructions.
This results in code which can run relatively efficiently on either a
68020/68881 or a 68030 or a 68040. The generated code does use the
68881 instructions that are emulated on the 68040.
The option is equivalent to -march=68020 -mtune=68020-40.
-m68020-60- Generate output for a 68060, without using any of the new instructions.
This results in code which can run relatively efficiently on either a
68020/68881 or a 68030 or a 68040. The generated code does use the
68881 instructions that are emulated on the 68060.
The option is equivalent to -march=68020 -mtune=68020-60.
-mhard-float-m68881- Generate floating-point instructions. This is the default for 68020
and above, and for ColdFire devices that have an FPU. It defines the
macro `__HAVE_68881__' on M680x0 targets and `__mcffpu__'
on ColdFire targets.
-msoft-float- Do not generate floating-point instructions; use library calls instead.
This is the default for 68000, 68010, and 68832 targets. It is also
the default for ColdFire devices that have no FPU.
-mdiv-mno-div- Generate (do not generate) ColdFire hardware divide and remainder
instructions. If -march is used without -mcpu,
the default is “on” for ColdFire architectures and “off” for M680x0
architectures. Otherwise, the default is taken from the target CPU
(either the default CPU, or the one specified by -mcpu). For
example, the default is “off” for -mcpu=5206 and “on” for
-mcpu=5206e.
gcc defines the macro `__mcfhwdiv__' when this option is enabled.
-mshort- Consider type
int to be 16 bits wide, like short int.
Additionally, parameters passed on the stack are also aligned to a
16-bit boundary even on targets whose API mandates promotion to 32-bit.
-mno-short- Do not consider type
int to be 16 bits wide. This is the default.
-mnobitfield-mno-bitfield- Do not use the bit-field instructions. The -m68000, -mcpu32
and -m5200 options imply -mnobitfield.
-mbitfield- Do use the bit-field instructions. The -m68020 option implies
-mbitfield. This is the default if you use a configuration
designed for a 68020.
-mrtd- Use a different function-calling convention, in which functions
that take a fixed number of arguments return with the
rtd
instruction, which pops their arguments while returning. This
saves one instruction in the caller since there is no need to pop
the arguments there.
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.)
The rtd instruction is supported by the 68010, 68020, 68030,
68040, 68060 and CPU32 processors, but not by the 68000 or 5200.
-mno-rtd- Do not use the calling conventions selected by -mrtd.
This is the default.
-malign-int-mno-align-int- Control whether GCC aligns
int, long, long long,
float, double, and long double variables on a 32-bit
boundary (-malign-int) or a 16-bit boundary (-mno-align-int).
Aligning variables on 32-bit boundaries produces code that runs somewhat
faster on processors with 32-bit busses at the expense of more memory.
Warning: if you use the -malign-int switch, GCC will
align structures containing the above types differently than
most published application binary interface specifications for the m68k.
-mpcrel- Use the pc-relative addressing mode of the 68000 directly, instead of
using a global offset table. At present, this option implies -fpic,
allowing at most a 16-bit offset for pc-relative addressing. -fPIC is
not presently supported with -mpcrel, though this could be supported for
68020 and higher processors.
-mno-strict-align-mstrict-align- Do not (do) assume that unaligned memory references will be handled by
the system.
-msep-data- Generate code that allows the data segment to be located in a different
area of memory from the text segment. This allows for execute in place in
an environment without virtual memory management. This option implies
-fPIC.
-mno-sep-data- Generate code that assumes that the data segment follows the text segment.
This is the default.
-mid-shared-library- Generate code that supports shared libraries via the library ID method.
This allows for execute in place and shared libraries in an environment
without virtual memory management. This option implies -fPIC.
-mno-id-shared-library- Generate code that doesn't assume ID based shared libraries are being used.
This is the default.
-mshared-library-id=n- Specified the identification number of the ID based shared library being
compiled. Specifying a value of 0 will generate more compact code, specifying
other values will force the allocation of that number to the current
library but is no more space or time efficient than omitting this option.