[Bug tree-optimization/68240] [6 Regression] compilation hangs on valid code at -O1 and above on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68240

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Starting iteration 95064
Value numbering iftmp.1_2 stmt = iftmp.1_2 = PHI <1(3), 0(4)>
Setting value number of iftmp.1_2 to iftmp.0_1 (changed)
Starting iteration 95065
Value numbering iftmp.1_2 stmt = iftmp.1_2 = PHI <1(3), 0(4)>
Setting value number of iftmp.1_2 to 1 (changed)
Starting iteration 95066
Value numbering iftmp.1_2 stmt = iftmp.1_2 = PHI <1(3), 0(4)>
Setting value number of iftmp.1_2 to iftmp.0_1 (changed)
Starting iteration 95067
Value numbering iftmp.1_2 stmt = iftmp.1_2 = PHI <1(3), 0(4)>
Setting value number of iftmp.1_2 to 1 (changed)
...

(oops)