[Bug tree-optimization/83194] Possibly missed simplification with strcmp(s, t) == strcmp(t, s)

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83194

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
You definitely cannot assume strcmp (s, t) == -strcmp (t, s), only that 
the result has the correct sign in each case.

There should be no need to preserve the exact return value (of the correct 
sign) chosen by the implementation in a particular case.