🚀 go-pugleaf

Dear GCC Wizards,

I have been hacking gcc and gcc manual. (Both Version 1.40)
Recently, I feel that something missing on page 125 of the
manual where it describes constraints.

On page 125 an insn is defined as
(define_insn ""
 [(set (match_operand:SI 0 "general_operand" "r")
       (plus:SI (match_operand:SI 1 "general_operand" "0")
                         |

However, form the definition on the previous page( P124),
I feel that we need to have an "=" for operand 0.
So, the first operand may be
 [(set (match_operand:SI 0 "general_operand" "=r")

How is this?

Just a comment. The difference between  match_dup and 'digit' for
constraint was hard to understand. I hope this section will be
revised for non expert readers. ( I guess I understand the
difference; however, still I do not have confidence, at this
moment)

Thank you for your time. Have nice weekend,

Koji Suginuma