Thumb Options
-------------
`-mthumb-interwork'
Generate code which supports calling between the THUMB and ARM
instruction sets. Without this option the two instruction sets
cannot be reliably used inside one program. The default is
`-mno-thumb-interwork', since slightly smaller code is generated
with this option.
`-mtpcs-frame'
Generate a stack frame that is compliant with the Thumb Procedure
Call Standard for all non-leaf functions. (A leaf function is one
that does not call any other functions). The default is
`-mno-apcs-frame'.
`-mtpcs-leaf-frame'
Generate a stack frame that is compliant with the Thumb Procedure
Call Standard for all leaf functions. (A leaf function is one
that does not call any other functions). The default is
`-mno-apcs-leaf-frame'.
`-mlittle-endian'
Generate code for a processor running in little-endian mode. This
is the default for all standard configurations.
`-mbig-endian'
Generate code for a processor running in big-endian mode.
`-mstructure-size-boundary=<n>'
The size of all structures and unions will be rounded up to a
multiple of the number of bits set by this option. Permissable
values are 8 and 32. The default value varies for different
toolchains. For the COFF targeted toolchain the default value is
8. Specifying the larger number can produced faster, more
efficient code, but can also increase the size of the program.
The two values are potentially incompatible. Code compiled with
one value cannot necessarily expect to work with code or libraries
compiled with the other value, if they exchange information using
structures or unions. Programmers are encouraged to use the 32
value as future versions of the toolchain may default to this
value.