As per my previous comments on this patch, I will not approve the changes to the m32c backend, as they will cause real bugs in real hardware, and violate the hardware's ABI. The user may use -fno-strict-volatile-bitfields if they do not desire this behavior and understand the consequences.
I am not a maintainer for the rx and h8300 ports, but they are in the same situation. To reiterate my core position: if the user defines a proper "volatile int" bitfield, and the compiler does anything other than an int-sized access, the compiler is WRONG. Any optimization that changes volatile accesses to something other than what the user specified is a bug that needs to be fixed before this option can be non-default.
