3.17.21 M32R/D Options
These -m options are defined for Renesas M32R/D architectures:
-m32r2- Generate code for the M32R/2.
-m32rx- Generate code for the M32R/X.
-m32r- Generate code for the M32R. This is the default.
-mmodel=small- Assume all objects live in the lower 16MB of memory (so that their addresses
can be loaded with the
ld24 instruction), and assume all subroutines
are reachable with the bl instruction.
This is the default.
The addressability of a particular object can be set with the
model attribute.
-mmodel=medium- Assume objects may be anywhere in the 32-bit address space (the compiler
generates
seth/add3 instructions to load their addresses), and
assume all subroutines are reachable with the bl instruction.
-mmodel=large- Assume objects may be anywhere in the 32-bit address space (the compiler
generates
seth/add3 instructions to load their addresses), and
assume subroutines may not be reachable with the bl instruction
(the compiler generates the much slower seth/add3/jl
instruction sequence).
-msdata=none- Disable use of the small data area. Variables are put into
one of ‘.data’, ‘.bss’, or ‘.rodata’ (unless the
section attribute has been specified).
This is the default.
The small data area consists of sections ‘.sdata’ and ‘.sbss’.
Objects may be explicitly put in the small data area with the
section attribute using one of these sections.
-msdata=sdata- Put small global and static data in the small data area, but do not
generate special code to reference them.
-msdata=use- Put small global and static data in the small data area, and generate
special instructions to reference them.
-G num- Put global and static objects less than or equal to num bytes
into the small data or BSS sections instead of the normal data or BSS
sections. The default value of num is 8.
The -msdata option must be set to one of ‘sdata’ or ‘use’
for this option to have any effect.
All modules should be compiled with the same -G num value.
Compiling with different values of num may or may not work; if it
doesn't the linker gives an error message—incorrect code is not
generated.
-mdebug- Makes the M32R-specific code in the compiler display some statistics
that might help in debugging programs.
-malign-loops- Align all loops to a 32-byte boundary.
-mno-align-loops- Do not enforce a 32-byte alignment for loops. This is the default.
-missue-rate=number- Issue number instructions per cycle. number can only be 1
or 2.
-mbranch-cost=number- number can only be 1 or 2. If it is 1 then branches are
preferred over conditional code, if it is 2, then the opposite applies.
-mflush-trap=number- Specifies the trap number to use to flush the cache. The default is
12. Valid numbers are between 0 and 15 inclusive.
-mno-flush-trap- Specifies that the cache cannot be flushed by using a trap.
-mflush-func=name- Specifies the name of the operating system function to call to flush
the cache. The default is _flush_cache, but a function call
is only used if a trap is not available.
-mno-flush-func- Indicates that there is no OS function for flushing the cache.