https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61969
--- Comment #6 from Andi Kleen <andi-gcc at firstfloor dot org> --- I looked at this a bit more. It's definitely the nrv pass that causes the problem. When I disable it in the source code the 32bit version compiles correctly. I also tried disabling the next pass (cfgcleanup), but that didn't make a difference. It converts the local variable to be a value-expr. It's still not exactly clear who deletes the variable declaration though. There are two possibilities: - nrv shouldn't convert the variable in the first place - someone who messes with the variables forgets to check for value-exprs. ;; Function func_52 (func_52, funcdef_no=86, decl_uid=2858, cgraph_uid=54, symbol_order=1152) NRV Replaced: l_55 with: <retval> func_52 (uint32_t p_53) { extern const struct S0 l_55 = {.f0=4, .f1=40290, .f2=10, .f3=4} [value-expr: <retval>]; <bb 2>: return <retval>; }