https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69992
--- Comment #3 from acsawdey at gcc dot gnu.org ---
So, it comes down to the fact that this condition cannot ever be true, so the
loop is not in fact infinite:
infinite if: (expr_list:REG_DEP_TRUE (ne:SI (and:DI (minus:DI (plus:DI
(ashift:DI (reg:DI 211)
(const_int 2 [0x2]))
(reg/v/f:DI 205 [ ap ]))
(reg:DI 193 [ ivtmp.20 ]))
(const_int 3 [0x3]))
(const_int 0 [0]))
(nil))
DI 211 is just n-1
ivtmp.20 is initialized to ap-4 and is incremented by 4 so has a value of the
form ap-4+4*i.
So the whole thing looks like
4*(n-1)+ap-(ap-4+4*i)
or
4*(n-1)+4-4*i which is 4*(n-1+1-i)
and clearly the low 2 bits are always 0.
So, should some analysis have figured this out?
