[Bug tree-optimization/68946] [6 Regression] ICE at -O3 on x86_64-linux-gnu in both 32- and 64-bit modes (in vect_analyze_stmt, at tree-vect-stmts.c:8013)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68946

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hmpf.  So we have

t.c:16:11: note: node
t.c:16:11: note:        stmt 0 _39 = iftmp.2_36 | _113;
t.c:16:11: note:        stmt 1 _113 = iftmp.2_112 | _100;
t.c:16:11: note:        stmt 2 _100 = iftmp.2_99 | _87;
t.c:16:11: note:        stmt 3 _87 = iftmp.2_86 | _74;
t.c:16:11: note:        stmt 4 _74 = iftmp.2_73 | _28;
t.c:16:11: note:        stmt 5 _28 = iftmp.2_37 | _44;
t.c:16:11: note:        stmt 6 _44 = iftmp.2_43 | _11;
t.c:16:11: note:        stmt 7 _11 = iftmp.2_3 | pretmp_19;

(see the "recursive use" of _113 for example) and

t.c:16:11: note: node (external)
t.c:16:11: note:        stmt 0 _113 = iftmp.2_112 | _100;
t.c:16:11: note:        stmt 1 _100 = iftmp.2_99 | _87;
t.c:16:11: note:        stmt 2 _87 = iftmp.2_86 | _74;
t.c:16:11: note:        stmt 3 _74 = iftmp.2_73 | _28;
t.c:16:11: note:        stmt 4 _28 = iftmp.2_37 | _44;
t.c:16:11: note:        stmt 5 _44 = iftmp.2_43 | _11;
t.c:16:11: note:        stmt 6 _11 = iftmp.2_3 | pretmp_19;
t.c:16:11: note:        stmt 7 pretmp_19 = c;