[llvm-dev] Disable memset synthesis

Tim Northover via llvm-dev
Wed, 16 Aug 2017 04:37:58 -0000

On 15 August 2017 at 19:38, bharathi seshadri via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> I find that GCC has an option -fno-tree-loop-distribute-patterns that
> can be used to disable memcpy/memset synthesis. I wonder if there is
> something similar in llvm/clang.

I have no idea what that means, but we almost certainly don't have any
option with similar semantics. Clang does not provide options to
control specific optimization passes like that.

The best advice is to file a bug report about the situation you're
seeing where a call to memset is bad for performance. There's clearly
something going wrong with Clang's heuristics and the best solution is
to fix that.

Cheers.

Tim.