Le mardi 28 février 2017, 06:10:45 CET Richard Henderson a écrit : > On 02/27/2017 10:22 PM, Eric Bischoff wrote: > > From: Eric Bischoff <ebisch...@nerim.net> > > > > LPD = LOAD PAIR DISJOINT > > --- > > > > target/s390x/insn-data.def | 4 +++- > > target/s390x/translate.c | 21 +++++++++++++++++++++ > > 2 files changed, 24 insertions(+), 1 deletion(-) > > > > diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def > > index 075ff59..e427988 100644 > > --- a/target/s390x/insn-data.def > > +++ b/target/s390x/insn-data.def > > @@ -504,7 +504,9 @@ > > > > C(0xb9e2, LOCGR, RRF_c, LOC, r1, r2, r1, 0, loc, 0) > > C(0xebf2, LOC, RSY_b, LOC, r1, m2_32u, new, r1_32, loc, 0) > > C(0xebe2, LOCG, RSY_b, LOC, r1, m2_64, r1, 0, loc, 0) > > > > -/* LOAD PAIR DISJOINT TODO */ > > +/* LOAD PAIR DISJOINT */ > > + C(0xc804, LPD, SSF, ILA, m1_32s, m2_32s, 0, r3_P32, movx, zero) > > + C(0xc805, LPDG, SSF, ILA, m1_64, m2_64, 0, r3_P64, movx, zero) > > The think is, in order to be able to say that the two loads were > interlocked, which is what you're doing with CC=0, we need to provide some > atomicity. > > In general, this is going to require that you check parallel_cpus, and if > true, signal cpu_loop_exit_atomic. > > As a special case, it would be possible to check for two loads that happen > to be sequential and perform them as an atomic read. Whether that happens > often enough to be worthwhile I don't know.
Understood now. I'm working on a v3 patch based on the code kindly sent in private mail by Richard. -- Eric Bischoff - SUSE Manager QA Engineer SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nürnberg)
