[Bug tree-optimization/77445] [7 Regression] Performance drop after r239219 on coremark test

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77445

--- Comment #14 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
With the patch we only give up on some threading in thread4:

q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.
q.c.181t.thread4:FSM jump-thread path not considered: duplication of 5 insns is
needed and optimizing for size.


How does that affect the actual benchmark? We may experiment with jump
threading whenever the destination BB is hot, not just edge itself as
duplicating the path also simplifies the surrounding code.