https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71724
Alan Modra <amodra at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2016-08-09 CC| |amodra at gmail dot com Ever confirmed|0 |1 --- Comment #1 from Alan Modra <amodra at gmail dot com> --- combine goes into infinite recursion inside this call: newpat = subst (newpat, i0dest, i0src, 0, 0, 0); The args of the failing subst are: x: (parallel [ (set (reg:SI 181) (plus:SI (ltu:SI (plus:SI (reg:SI 165) (reg:SI 174 [ t9.0_1+4 ])) (reg:SI 165)) (reg:SI 173 [ t9.0_1 ]))) (clobber (reg:SI 76 ca)) ]) from: (reg:SI 174 [ t9.0_1+4 ]) to: (if_then_else:SI (eq (reg:CC 185) (const_int 0 [0])) (reg:SI 165) (reg:SI 174 [ t9.0_1+4 ]))