search for: ldstptrreg

I can't get it to work with pattern matching. My operand is defined like so: def LDSTPtrReg : Operand<i16> { let MIOperandInfo = (ops PTRREGS); let EncoderMethod = "encodeLDSTPtrReg"; } I am able to use it in the place of PTRREGS in the definition of the LD instruction, but if I use it in an instruction matching pattern, compilation fails with the error "Unkn...

I'm attempting to implement codegen support for the AVR ST/LD <http://www.atmel.com/webdoc/avrassembler/avrassembler.wb_ST.html> family of instructions. The binary encoding is not particularly consistent -- take a look at this table of variants of LD, along with their machine code representation: # load 8 bits from pointer register X into general purpose Rd ld Rd, X `1001 000d dddd

Thanks. I saw the header comments but it wasn’t clear to me what the difference between those concepts is? My slightly vague understanding is IsDef means that the register specified by this operand is set by the machine instruction. So I understand that to mean the MO will override that register? Also things like early clobber, perhaps there is another document that clarifies some of these