[Bug target/109093] [13 regression] csmith: a February runtime bug ?

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109093

--- Comment #21 from H.J. Lu <hjl.tools at gmail dot com> ---
REG_EQUIV is added by IRA:

          if (DF_REG_DEF_COUNT (regno) == 1
              && note
              && !rtx_varies_p (XEXP (note, 0), 0)
              && (!may_trap_or_fault_p (XEXP (note, 0))
                  || def_dominates_uses (regno))) 
            {
              rtx note_value = XEXP (note, 0);
              remove_note (insn, note);
              set_unique_reg_note (insn, REG_EQUIV, note_value);
            }