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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 will generate 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 will generate seth/add3 instructions to load their addresses), and assume subroutines may not be reachable with the bl instruction (the compiler will generate the much slower seth/add3/jl instruction sequence).
-msdata=none
Disable use of the small data area. Variables will be 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 will give an error message—incorrect code will not be 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 will be preferred over conditional code, if it is 2, then the opposite will apply.
-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 will only be used if a trap is not available.
-mno-flush-func
Indicates that there is no OS function for flushing the cache.