Currently sequences reduction_add(ext(<n x i1>)) are modeled as vector
extensions + reduction add, but later instcombiner transforms it into
ext(ctcpop(bitcast <n x i1> to int n)). Patch adds direct support for
this in SLP vectorizer, which enables better cost estimation.
AVX512, -O3+LTO
CINT2006/445.gobmk - extra vector code
Prolangs-C/bison - extra vector code
Benchmarks/NPB-serial/is - 16 x + 8 x reductions vectorized as 24
x reduction
Reviewers: RKSimon
Reviewed By: RKSimon
Pull Request: https://github.com/llvm/llvm-project/pull/116875
14bdcefbd8