[Bug tree-optimization/79460] gcc fails to optimise out a trivial additive loop for seemingly arbitrary numbers of iterations

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79460

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Shouldn't it (both in the vectorizer and in scev) be dependent not just on
flag_fp_contract_mode but also on some -ffast-math subflag?  Doing several
additions can e.g. raise different exceptions and have different roundings from
doing it as just one multiply.