On 03/06/16 21:27, Pranith Kumar wrote: > On Thu, Jun 2, 2016 at 5:18 PM, Richard Henderson <r...@twiddle.net> wrote: >> > >> > Hum. That does seem helpful-ish. But I'm not certain how helpful it is to >> > complicate the helper functions even further. >> > >> > What if we have tcg_canonicalize_memop (or some such) split off the >> > barriers >> > into separate opcodes. E.g. >> > >> > MO_BAR_LD_B = 32 // prevent earlier loads from crossing current op >> > MO_BAR_ST_B = 64 // prevent earlier stores from crossing current op >> > MO_BAR_LD_A = 128 // prevent later loads from crossing current op >> > MO_BAR_ST_A = 256 // prevent later stores from crossing current op >> > MO_BAR_LDST_B = MO_BAR_LD_B | MO_BAR_ST_B >> > MO_BAR_LDST_A = MO_BAR_LD_A | MO_BAR_ST_A >> > MO_BAR_MASK = MO_BAR_LDST_B | MO_BAR_LDST_A >> > >> > // Match Sparc MEMBAR as the most flexible host. >> > TCG_BAR_LD_LD = 1 // #LoadLoad barrier >> > TCG_BAR_ST_LD = 2 // #StoreLoad barrier >> > TCG_BAR_LD_ST = 4 // #LoadStore barrier >> > TCG_BAR_ST_ST = 8 // #StoreStore barrier >> > TCG_BAR_SYNC = 64 // SEQ_CST barrier > I really like this format. I would also like to add to the frontend: > > MO_BAR_ACQUIRE > MO_BAR_RELEASE > > and the following to the backend: > > TCG_BAR_ACQUIRE > TCG_BAR_RELEASE > > since these are one-way barriers and the previous barrier types do not > cover them. >
Well, my last comment about acq/rel barriers should really go here [Message-Id: 5751df2d.5040...@gmail.com] Regards, Sergey
