Re: [PATCH V2] Disable sched1 in functions that call setjmp

[Qing Zhao via Gcc-patches]

> On Dec 23, 2022, at 2:36 PM, Alexander Monakov <amona...@ispras.ru> wrote:
> 
> 
> 
> On Fri, 23 Dec 2022, Qing Zhao wrote:
> 
>> Then, sched2 still can move insn across calls? 
>> So does sched2 have the same issue of incorrectly moving  the insn across a 
>> call which has unknown control flow?
> 
> I think problems are unlikely because register allocator assigns pseudos that
> cross setjmp to memory.
> 
> I think you hit the problem with sched1 because most testing is done on x86 
> and
> sched1 is not enabled there, otherwise the problem would have been noticed 
> much
> earlier.


Yes, the problem with this bug is in sched1 on aarch64.  On x86 the same issue 
will be exposed when explicitly enable sched1 with -fschedule-insns. 

BTW, Why sched1 is not enabled on x86 by default?

Another question is:  As discussed in the original bug PR57067: 
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57067
The root cause of this issue related to the abnormal control flow edges (from 
setjmp/longjmp) cannot be represented correctly at RTL stage, shall we fix
this root cause instead? 

Qing


> Alexander