From a920979d4f30a48a23f8ff375ce05fa8a947dd96 Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Fri, 16 Nov 2018 10:46:27 -0600 Subject: [PATCH] intel/fs: Use split sends for surface writes on gen9+ Surface reads don't need them because they just have the one address payload. With surface writes, on the other hand, we can put the address and the data in the different halves and avoid building the payload all together. The decrease in register pressure and added freedom in register allocation resulting from this change reduces spilling enough to improve the performance of one customer benchmark by about 2x. Reviewed-by: Iago Toral Quiroga --- src/intel/compiler/brw_fs.cpp | 50 ++++++++++++++++++++++++------------- src/intel/compiler/brw_fs_builder.h | 15 +++++++++++ 2 files changed, 47 insertions(+), 18 deletions(-) diff --git a/src/intel/compiler/brw_fs.cpp b/src/intel/compiler/brw_fs.cpp index d82572a..8dd3b94 100644 --- a/src/intel/compiler/brw_fs.cpp +++ b/src/intel/compiler/brw_fs.cpp @@ -5016,28 +5016,42 @@ lower_surface_logical_send(const fs_builder &bld, fs_inst *inst) * Gen11+ the header has been removed so we can only use predication. */ const unsigned header_sz = devinfo->gen < 9 && is_typed_access ? 1 : 0; - const unsigned sz = header_sz + addr_sz + src_sz; - - /* Allocate space for the payload. */ - fs_reg *const components = new fs_reg[sz]; - const fs_reg payload = bld.vgrf(BRW_REGISTER_TYPE_UD, sz); - unsigned n = 0; const bool has_side_effects = inst->has_side_effects(); fs_reg sample_mask = has_side_effects ? bld.sample_mask_reg() : fs_reg(brw_imm_d(0xffff)); - /* Construct the payload. */ - if (header_sz) - components[n++] = emit_surface_header(bld, sample_mask); + fs_reg payload, payload2; + unsigned mlen, ex_mlen = 0; + if (devinfo->gen >= 9) { + /* We have split sends on gen9 and above */ + assert(header_sz == 0); + payload = bld.move_to_vgrf(addr, addr_sz); + payload2 = bld.move_to_vgrf(src, src_sz); + mlen = addr_sz * (inst->exec_size / 8); + ex_mlen = src_sz * (inst->exec_size / 8); + } else { + /* Allocate space for the payload. */ + const unsigned sz = header_sz + addr_sz + src_sz; + payload = bld.vgrf(BRW_REGISTER_TYPE_UD, sz); + fs_reg *const components = new fs_reg[sz]; + unsigned n = 0; + + /* Construct the payload. */ + if (header_sz) + components[n++] = emit_surface_header(bld, sample_mask); + + for (unsigned i = 0; i < addr_sz; i++) + components[n++] = offset(addr, bld, i); - for (unsigned i = 0; i < addr_sz; i++) - components[n++] = offset(addr, bld, i); + for (unsigned i = 0; i < src_sz; i++) + components[n++] = offset(src, bld, i); - for (unsigned i = 0; i < src_sz; i++) - components[n++] = offset(src, bld, i); + bld.LOAD_PAYLOAD(payload, components, sz, header_sz); + mlen = header_sz + (addr_sz + src_sz) * inst->exec_size / 8; - bld.LOAD_PAYLOAD(payload, components, sz, header_sz); + delete[] components; + } /* Predicate the instruction on the sample mask if no header is * provided. @@ -5162,7 +5176,8 @@ lower_surface_logical_send(const fs_builder &bld, fs_inst *inst) /* Update the original instruction. */ inst->opcode = SHADER_OPCODE_SEND; - inst->mlen = header_sz + (addr_sz + src_sz) * inst->exec_size / 8; + inst->mlen = mlen; + inst->ex_mlen = ex_mlen; inst->header_size = header_sz; inst->send_has_side_effects = has_side_effects; inst->send_is_volatile = !has_side_effects; @@ -5183,10 +5198,9 @@ lower_surface_logical_send(const fs_builder &bld, fs_inst *inst) /* Finally, the payload */ inst->src[2] = payload; + inst->src[3] = payload2; - inst->resize_sources(3); - - delete[] components; + inst->resize_sources(4); } static void diff --git a/src/intel/compiler/brw_fs_builder.h b/src/intel/compiler/brw_fs_builder.h index c50af4c..3fc6e5f 100644 --- a/src/intel/compiler/brw_fs_builder.h +++ b/src/intel/compiler/brw_fs_builder.h @@ -426,6 +426,21 @@ namespace brw { return src_reg(component(dst, 0)); } + src_reg + move_to_vgrf(const src_reg &src, unsigned num_components) const + { + src_reg *const src_comps = new src_reg[num_components]; + for (unsigned i = 0; i < num_components; i++) + src_comps[i] = offset(src, dispatch_width(), i); + + const dst_reg dst = vgrf(src.type, num_components); + LOAD_PAYLOAD(dst, src_comps, num_components, 0); + + delete[] src_comps; + + return src_reg(dst); + } + void emit_scan(enum opcode opcode, const dst_reg &tmp, unsigned cluster_size, brw_conditional_mod mod) const -- 2.7.4