1. A method of executing program instructions, the method comprising: receiving, in a processor, an instruction; generating an exception when the instruction will cause the processor to read data from or write data to a portion of memory that is shared by one or more processes; and executing, in response to the exception, an exception handling routine with alternate instructions in place of the received instruction, the alternate instructions causing the processor to: (a) read or write the data from or to the portion of memory in a first format; and (b) transform the read or write data to a second format.