[Bug middle-end/107487] New: Issue an error for illegal digit constraint.

[Bug middle-end/107487] New: Issue an error for illegal digit constraint.

[crazylht at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107487

            Bug ID: 107487
           Summary: Issue an error for illegal digit constraint.
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: crazylht at gmail dot com
  Target Milestone: ---

This is orginally from PR107057, 


(In reply to Hongtao.liu from comment #7)
> And it looks like the pattern is wrongly defined since from [1].
> 
> ----------cut begin------------
> Matching constraints are used in these circumstances. More precisely, the
> two operands that match must include one input-only operand and one
> output-only operand. Moreover, the digit must be a smaller number than the
> number of the operand that uses it in the constraint.
> ----------------cut end----------
> 
> (define_insn "vec_concatv2df"
>   [(set (match_operand:V2DF 0 "register_operand"     "=x,x,v,x,v,x,x, v,x,x")
> 	(vec_concat:V2DF
> 	  (match_operand:DF 1 "nonimmediate_operand" " 0,x,v,m,m,0,x,vm,0,0")
> 	  (match_operand:DF 2 "nonimm_or_0_operand"  " x,x,v,1,1,m,m, C,x,m")))]
> 
> 
> For alternatvie 1, the two operands are both input only.
> 
> [1]
> https://gcc.gnu.org/onlinedocs/gccint/Simple-Constraints.html#Simple-
> Constraints


Perhaps an error should be emitted for this situation?