[Bug rtl-optimization/59019] [4.9 regression] ICE in advance_target_bb, at sched-rgn.c:3561

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59019

--- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Always considering trap-if as ending a BB appears to be a bit of a rathole. 
> Every time I squash one issue, another raises its head.

A little unexpected I'd say, what kind of issues does that introduce?

> I did find that combine.c already has some bits to recognize when it does
> something that may muck up the CFG and tries to compensate, it just doesn't
> hadle the situation around trap-if.
> 
> I'm going to see if I can proof of concept a fix in that code.  Of course
> this is a pass specific fix, but as I look deeper, more memories keep coming
> back -- we've had special code in cse.c to deal with similar situations, so
> maybe adding another case for combine isn't that bad after all.

See existing examples in split_all_insns and lra.