[Bug rtl-optimization/65504] [4.9/5 Regression] select case with strings and -fgcse -O

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65504
--- Comment #15 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
It's a bug in Dead Store Elimination (so -fno-dse is the workaround) exposed by
a combination of GCSE and FWPROP which changes the canonicalization of
addresses (so -fno-gcse and -fno-forward-propagate paper over the bug).