[Bug middle-end/87276] [9 Regression] Buggy tree-ssa optimization introduced in revision 263875

[vincent-gcc at vinc17 dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87276

--- Comment #6 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
Note concerning the tests: in Debian, as of gcc-snapshot 1:20181209-1, MPFR is
no longer affected (and I've checked that the failure is still reproducible
with gcc-snapshot 1:20181127-1). But the testcase in Comment 1 still fails.