On Sat, Apr 16, 2016 at 10:36 AM, Marek Olšák <mar...@gmail.com> wrote: > On Sat, Apr 16, 2016 at 3:28 PM, Roland Scheidegger <srol...@vmware.com> > wrote: >> Am 16.04.2016 um 15:19 schrieb eocallag...@alterapraxis.com: >>> On 2016-04-16 20:20, Marek Olšák wrote: >>>> On Sat, Apr 16, 2016 at 8:04 AM, Michel Dänzer <mic...@daenzer.net> >>>> wrote: >>>>> On 16.04.2016 14:51, Michel Dänzer wrote: >>>>>> On 16.04.2016 11:39, Tom Stellard wrote: >>>>>>> The ds_bpermute instruction allows threads to transfer data directly >>>>>>> to or from the vgprs of other threads. These instructions use the lds >>>>>>> hardware to transfer data, but do not read or write lds memory. >>>>>>> >>>>>>> DDX BEFORE: | DDX AFTER: >>>>>>> | >>>>>>> v_mbcnt_lo_u32_b32_e64 v2, -1, 0 | v_mbcnt_lo_u32_b32_e64 v2, -1, 0 >>>>>>> v_mbcnt_hi_u32_b32_e64 v2, -1, v2 | v_mbcnt_hi_u32_b32_e64 v2, >>>>>>> -1, v2 >>>>>>> v_lshlrev_b32_e32 v4, 2, v2 | v_and_b32_e32 v2, 0x3ffffffc, v2 >>>>>>> v_and_b32_e32 v2, -4, v2 | v_lshlrev_b32_e32 v2, 2, v2 >>>>>>> v_lshlrev_b32_e32 v3, 2, v2 | ds_bpermute_b32 v3, v2, v0 >>>>>>> s_mov_b32 m0, -1 | ds_bpermute_b32 v0, v2, v0 >>>>>>> offset:4 >>>>>>> ds_write_b32 v4, v0 | s_waitcnt lgkmcnt(0) >>>>>>> s_waitcnt lgkmcnt(0) | >>>>>>> v_or_b32_e32 v0, 1, v2 | >>>>>>> v_lshlrev_b32_e32 v0, 2, v0 | >>>>>>> ds_read_b32 v1, v3 | >>>>>>> ds_read_b32 v0, v0 | >>>>>>> s_waitcnt lgkmcnt(0) | >>>>>>> | >>>>>>> LDS: 1 blocks | LDS: 0 blocks >>>>>> >>>>>> Nice. >>>>>> >>>>>> >>>>>> Were these intrinsics already available in LLVM 3.6? If not, the old >>>>>> code needs to be kept for backwards compatibility. >>>>> >>>>> I can see now that you're taking care of this for the bpermute >>>>> intrinsic, but AFAICT the mbcnt intrinsics were only added in LLVM 3.8. >>>> >>>> How do you feel about increasing the requirement to LLVM 3.8 for Mesa >>>> git? >>> >>> +1 from me. Supporting more than two generations of LLVM is a bit much >>> to carry imho. >>> >> >> You don't want to support any released version which is older than one >> month? >> (This isn't an objection, just a remark...) > > Life's hard. Sometimes we have to make hard choices. :) > > Now seriously, LLVM 3.7 enables OpenGL 4.0-4.1 and LLVM 3.8 enables > immediate shader compilation (without recompilations) for radeonsi. > I'll let others assess how important those two are.
From a practical standpoint, gentoo and arch are shipping LLVM 3.7.1 by default. It may cause a bunch of frustration for people if you require 3.8. I don't actually build or use radeonsi, just pointing out some potentially pertinent facts. Cheers, -ilia _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
