nikic wrote: > > I don't think your general approach here is going to work. We need to be > > careful about introducing vector operations out of thin air, because LLVM > > is not going to second guess them. If you convert a memset to <32768 x i8> > > ops here, LLVM is going to carry those all they down, even though this is > > almost certainly not performant. Additionally, you are breaking the ability > > for SROA to split the alloca and fully promote parts of it. > > Is there an appropriate place in the code to decide if a splittable memset > should be promoted to a vector operation?
Basically: We should only do it if there already is an existing vector operation. If we have a memset and then a later load of e.g. `<16 x i8>`, then lowering the memset to `store <16 x i8> zeroinitializer` makes sense. But if we only have scalar operations, we should not be introducing vectors in SROA. https://github.com/llvm/llvm-project/pull/133301 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
