>> This is something Chris requested, IIRC. I'm not sure I remember the
>> motivation beyond that.
>
> Two reasons:
>
> 1) -O1 doesn't actually mean anything.  It is the optimization level least 
> understood by both the GCC folks and us.  Recently (last 5 years?) there has 
> been a move to try to make this "optimize without messing up debug info", but 
> this is a new movement.

Another thing that is making -O1 better defined is asan. It is the
optimization level that makes asan fast but still provides useful
backtraces :-)

> 2) Users who specify -O generally don't know it maps onto -O1.  They almost 
> certainly don't want whatever -O1 provides.  In my experience, most are 
> coming from Sun, HP or other compilers, where -O was a generally useful flag.
>
> 3) There are some benchmarks that pass -O (because of #2), which is 
> ridiculous, but reflects some reality that people use -O.  I don't recall 
> what these benchmarks were.
>
> These are reasons that I suggested the change.  I really don't like -O1 :-)

I haven't seen -O being used in wild, so I OK with keeping it mapping to -O2.

> -Chris

Thanks,
Rafael
_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits

Reply via email to