[LLVMdev] TableGen question

[Mohamed Shafi]

Hi,

In tablegen file inside class we have variables declared inside a
class. Say in PPC there is this

class BForm<bits<6> opcode, bit aa, bit lk, dag OOL, dag IOL, string asmstr>
  : I<opcode, OOL, IOL, asmstr, IIC_BrB> {
  bits<7> BIBO;  // 2 bits of BI and 5 bits of BO.
  bits<3>  CR;
  bits<14> BD;


How does the generator match each variable against an operand?

For the corresponding PPCGenMCCodeEmitter.inc for this the entry is

      // op: BIBO
      op = getMachineOpValue(MI, MI.getOperand(0), Fixups, STI);
      // op: CR
      op = getMachineOpValue(MI, MI.getOperand(1), Fixups, STI);
      // op: BD
      op = getCondBrEncoding(MI, 2, Fixups, STI);


How does the generator know that BIBO is op0 and CR is op1 and so on?
Is it based on the order of the declarations of the variables in the class?

Regards,
Shafi