https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83311
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |ASSIGNED Last reconfirmed| |2017-12-07 Version|unknown |8.0 Depends on| |82991 Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org Ever confirmed|0 |1 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- While I could special-case this it really depends on PR82991. The issue is we see <bb 2> : s_5 = __builtin_alloca (1); _1 = __builtin_memcpy (s_5, "a", 1); _2 = MEM[(char *)_1]; _7 = (int) _2; return _7; thus we read from _1 but we memcpy to s_5. One might consider it a duplicate of that PR even. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82991 [Bug 82991] memcpy and strcpy return value can be assumed to be equal to first argument