> One question: do you have an example of a non-volatile-safe machine so > I can get a feel for the problems one might encounter? At best I can > imagine a machine that optimizes "add 0, [mem]" to avoid the > read/write, but I'm not aware of such an ISA.
For example, the MSP430 backend uses a macro for movsi, addsipsi3, subpsi3, and a few others, which aren't volatile-safe. Look for "general_operand" vs "msp_general_operand".
