2014-03-03 13:34 GMT+04:00 S, Pitchumani <pitchuman...@atmel.com>: > Hi, > > Few AVR Xmega devices have specific instruction support than the architecture > it belongs to. For example atxmega128b1 device has RMW instructions (XCH,LAC, > LAS and LAT) support, but not all avrxmega6 devices have. > > Now, avr-gcc passes architecture name to assembler instead of device name. So, > RMW instructions are not recognized (illegal opcode error) by assembler. > > To address this issue, we could add device specific ISA to device details > in GCC. Driver can pass additional option based on specific ISA that a device > has. Assembler can add device specific ISA to architecture ISA based on the > option it receives. > > I have attached patches for avr-gcc. > > device-specific-isa-avr-gcc.patch: > * Device specific ISA information is added to device details. > * avr-gcc passes -mrmw option to assembler if the selected device > has RMW instruction support.
I don't like additional option '-mrmw' because we already have a way for passing device specific ISA. IMHO better to add new avr_arch (ie atxmega128b1 is ARCH_AVRXMEGA6U) GAS already have AVR_ISA_XMEGAU for RMW instructions. Denis.
