[PATCH] Preserve IR flags (nsw, nuw, exact, fast-math) in SLP vectorizer (PR20802)
nrotem at apple.com
Wed Sep 3 09:29:18 PDT 2014
LGTM! Thanks Sanjay!
> On Sep 3, 2014, at 9:01 AM, Sanjay Patel <spatel at rotateright.com> wrote:
> Hi nadav, aschwaighofer, hfinkel, karthikthecool, andreadb,
> The SLP vectorizer should propagate IR-level optimization hints/flags (nsw, nuw, exact, fast-math) when converting scalar instructions into vectors. But this isn't a simple copy - we need to take the intersection (the logical 'and') of the sets of flags on the scalars.
> The solution is further complicated because we can have non-uniform (non-SIMD) vector ops after:
> The vast majority of changed files are existing tests that were not propagating IR flags, but I've also added a new test file for focused testing of IR flag possibilities.
More information about the llvm-commits