[Bug tree-optimization/97737] [11 Regression] ICE at -Os and above: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in useless_type_conversion_p, at gimple-expr.c:88

[amacleod at redhat dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97737

Andrew Macleod <amacleod at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #3 from Andrew Macleod <amacleod at redhat dot com> ---
This is actually the same issue as 97741.  The iL is being changed and we lose
info.  The first thing visited is:

e_4 = PHI <1(2), e_3(7)>

and the incoming edge from bb7 is determined to be undefined, so we fold e_4 to
1
but later on the undefined edge becomes defined due a "harmless" constant in
unreachable code being propagated.

The end result is now:

<bb 2> :
  b = 1;
  a.0_1 = a;
  e_10 = 1 / a.0_1;
  if (e_10 == 0)
    goto <bb 3>; [INV]
  else
    goto <bb 4>; [INV]

  <bb 3> :
  c.1_2 = c;

  <bb 4> :
  return;

*** This bug has been marked as a duplicate of bug 97741 ***