[llvm-dev] -O1 with clang and gcc

[Michael Kruse via llvm-dev]

What are you trying to achieve? If faster runs is the goal, why not
compile with -O2?

Michael


2018-05-31 16:27 GMT-05:00 M. Chaturvedi via llvm-dev <llvm-dev at lists.llvm.org>:
> Hi,
>
> The binary gotten via clang's `-O1` runs much slower (3x) than that gotten
> via GCC's `-O1`.
>
> Reproducible with:
>
> https://github.com/m-chaturvedi/test_valgrind_slowdown
>
> We are seeing this difference between gcc and clang at other places as well.
>
> The `-O0` and `-O2` times are comparable, however.   Are there some compile
> time flags one could add to make the `-O1` times comparable?
>
> Apologies if this has been discussed somewhere already.
>
> Thank you,
> Mmanu
>
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>