[Bug rtl-optimization/72488] [7 Regression] wrong code (SIGFPE) at -Os and above on x86_64-linux-gnu (in the 64-bit mode)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72488

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
-fdisable-tree-vrp1 "fixes" it (yes, the revision uncovered a latent bug). 
VRP1
performs a lot of jump-threading thus it isn't very likely the culprit.

Program received signal SIGFPE, Arithmetic exception.
0x0000000000401194 in fn1 () at t.c:130
130           t4 = -(~r % ~e | t17 & t23 / t18 / t4 - t9 % l ^ o);
(gdb) p t18
$1 = 0

The testcase is extremely large and has many irreducible regions so it's hard
to see what goes wrong.

Passes sofar trimmed down to

-Os -fno-tree-sink -fno-tree-reassoc -fno-tree-loop-im -fno-tree-pre
-fdisable-tree-ifcombine -fno-tree-loop-optimize  -fno-tree-forwprop
-fdisable-tree-vrp2
-fdisable-tree-phiopt3 -fdisable-tree-phiopt2