[LLVMdev] Pat operands matching example in ppc

[Anitha B Gollamudi]

Hi,


How do "Pat" operands get matched? I am trying to follow the example given
in http://llvm.org/docs/CodeGenerator.html#selectiondag-process

In the latest trunk of ppcintrinfo.td following pattern is defined:

def : Pat<(pre_store i32:$rS, iPTR:$ptrreg, iaddroff:$ptroff),
              (STWU $rS, iaddroff:$ptroff, $ptrreg)>;

I understand that input operand list i.e. ins of stwu should get matched
with the given pre_store. But I am confused as to how  "ptroff" and
"ptrreg" get matched with "memri" used in STWU?


For reference[1] memri is defined as:

def memri :Operand<iPTR> {  let PrintMethod = "printMemRegImm";
 let MIOperandInfo = (ops dispRI:$imm,  ptr_rc_nor0:$reg);
 let EncoderMethod = "getMemRIEncoding";}

[1]
https://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/PowerPC/PPCInstrInfo.td?view=markup
-- 
* Anitha*
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