On Mon, Jun 28, 2021 at 06:26:52AM -0700, Richard Henderson wrote: > On 6/28/21 5:58 AM, Ulrich Weigand wrote: > >>>helper.h:DEF_HELPER_FLAGS_3(clgdb, TCG_CALL_NO_WG, i64, env, i64, i32) > >> > >>This won't work reliably. You're writing to a tcg global inside of > >>a function that says that it won't. > > > >I missed that, sorry. That problem can be fixed by changing the above > >line to something like: > >DEF_HELPER_3(clgdb, i64, env, i64, i32) > >right? > > Yes.
OK, I'll send a v2 including that change shortly; maybe that is an acceptable fix for the immediate bug, at least for now. > >In any case, the current implementation already has two helpers, and > >I initially tried to keep that, by using a different second part to > >correctly compute CC. But this ran into the problem that I didn't > >see any way to detect the fact that the conversion operation had run > >into one of the special cases in the second helper, without re-doing > >the whole conversion a second time. Is there any way to pass > >information between the two helpers (without running again into the > >same qemu global state updating problem)? > > Don't clear out env->fpu_status.float_exception_flags in > handle_exceptions. Wait until we're actually done with the data. I don't really know much about qemu internals, but this is really confusing me, sorry. Aren't env->fpu_status and env->cc_op two elements of the same global state? Why it is OK to use one of these fields to pass information to the next helper, but not the other? I guess I must be missing something here ... Bye, Ulrich -- Dr. Ulrich Weigand GNU/Linux compilers and toolchain ulrich.weig...@de.ibm.com
