On Wed, Jan 27, 2021 at 4:40 AM Alexandre Oliva <ol...@adacore.com> wrote:
> This patch attempts to fix a libgcc codegen regression introduced in
> gcc-10, as -ftree-loop-distribute-patterns was enabled at -O2.
>
> RISC-V doesn't have any setmemM pattern, so the loops above end up
> "optimized" into memset calls, incurring not only the overhead of an
> explicit call, but also discarding the information the compiler has
> about the alignment of the destination, and that the length is a
> multiple of the word alignment.
>
> FYI we have a bug report for this for a coremark regression which sounds
like the same problem.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94092
Jim
