https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83128
Bug ID: 83128 Summary: Unable to optimize {m,c}alloc when strings builtin are used Product: gcc Version: unknown Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: denis.campredon at gmail dot com Target Milestone: --- Currently gcc with -03 is able to optimize ---------- char f() { char * i = (char*)__builtin_malloc(100); i[0] = 'a'; return i[0]; } ---------- to ---------- mov al, 97 ret But is unable to do the same when string builtins are used with either malloc or calloc. --------- char f() { char * i = (char*)__builtin_malloc(100); __builtin_memcpy(i, "a", 1); return i[0]; } ---------