[Bug c++/56493] [4.8/4.9/5 Regression] Performance regression in google dense hashmap

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56493

--- Comment #17 from Richard Biener <rguenth at gcc dot gnu.org> ---
Btw, I think that

(int) ((long unsigned int) q + D.2078)

to

(int) ((unsigned int) q + (unsigned int) D.2078)

doesn't look like an always profitable pattern on GIMPLE (more stmts).  Also
take into consideration what targets PROMOTE_MODE (mode-of-q/D.2078) do
and prefer types according to that.

The vectorizer prefers single type sizes throughout computations to avoid
re-packing.