static void gen6_update_sol_surfaces(struct brw_context *brw) { struct gl_context *ctx = &brw->ctx; /* BRW_NEW_TRANSFORM_FEEDBACK */ struct gl_transform_feedback_object *xfb_obj = ctx->TransformFeedback.CurrentObject; /* BRW_NEW_VERTEX_PROGRAM */ const struct gl_shader_program *shaderprog = ctx->Shader.CurrentVertexProgram; const struct gl_transform_feedback_info *linked_xfb_info = &shaderprog->LinkedTransformFeedback; int i; for (i = 0; i < BRW_MAX_SOL_BINDINGS; ++i) { const int surf_index = SURF_INDEX_GEN6_SOL_BINDING(i); if (_mesa_is_xfb_active_and_unpaused(ctx) && i < linked_xfb_info->NumOutputs) { unsigned buffer = linked_xfb_info->Outputs[i].OutputBuffer; unsigned buffer_offset = xfb_obj->Offset[buffer] / 4 + linked_xfb_info->Outputs[i].DstOffset; brw_update_sol_surface( brw, xfb_obj->Buffers[buffer], &brw->ff_gs.surf_offset[surf_index], linked_xfb_info->Outputs[i].NumComponents, linked_xfb_info->BufferStride[buffer], buffer_offset); } else { brw->ff_gs.surf_offset[surf_index] = 0; } } brw->state.dirty.brw |= BRW_NEW_SURFACES; }
static void gen6_update_sol_surfaces(struct brw_context *brw) { struct gl_context *ctx = &brw->ctx; /* BRW_NEW_TRANSFORM_FEEDBACK */ struct gl_transform_feedback_object *xfb_obj = ctx->TransformFeedback.CurrentObject; const struct gl_shader_program *shaderprog; const struct gl_transform_feedback_info *linked_xfb_info; int i; if (brw->geometry_program) { /* BRW_NEW_GEOMETRY_PROGRAM */ shaderprog = ctx->_Shader->CurrentProgram[MESA_SHADER_GEOMETRY]; } else { /* BRW_NEW_VERTEX_PROGRAM */ shaderprog = ctx->_Shader->CurrentProgram[MESA_SHADER_VERTEX]; } linked_xfb_info = &shaderprog->LinkedTransformFeedback; for (i = 0; i < BRW_MAX_SOL_BINDINGS; ++i) { const int surf_index = SURF_INDEX_GEN6_SOL_BINDING(i); if (_mesa_is_xfb_active_and_unpaused(ctx) && i < linked_xfb_info->NumOutputs) { unsigned buffer = linked_xfb_info->Outputs[i].OutputBuffer; unsigned buffer_offset = xfb_obj->Offset[buffer] / 4 + linked_xfb_info->Outputs[i].DstOffset; if (brw->geometry_program) { brw_update_sol_surface( brw, xfb_obj->Buffers[buffer], &brw->gs.base.surf_offset[surf_index], linked_xfb_info->Outputs[i].NumComponents, linked_xfb_info->Buffers[buffer].Stride, buffer_offset); } else { brw_update_sol_surface( brw, xfb_obj->Buffers[buffer], &brw->ff_gs.surf_offset[surf_index], linked_xfb_info->Outputs[i].NumComponents, linked_xfb_info->Buffers[buffer].Stride, buffer_offset); } } else { if (!brw->geometry_program) brw->ff_gs.surf_offset[surf_index] = 0; else brw->gs.base.surf_offset[surf_index] = 0; } } brw->ctx.NewDriverState |= BRW_NEW_SURFACES; }
/** * Generate the geometry shader program used on Gen6 to perform stream output * (transform feedback). */ void gen6_sol_program(struct brw_ff_gs_compile *c, struct brw_ff_gs_prog_key *key, unsigned num_verts, bool check_edge_flags) { struct brw_codegen *p = &c->func; brw_inst *inst; c->prog_data.svbi_postincrement_value = num_verts; brw_ff_gs_alloc_regs(c, num_verts, true); brw_ff_gs_initialize_header(c); if (key->num_transform_feedback_bindings > 0) { unsigned vertex, binding; struct brw_reg destination_indices_uw = vec8(retype(c->reg.destination_indices, BRW_REGISTER_TYPE_UW)); /* Note: since we use the binding table to keep track of buffer offsets * and stride, the GS doesn't need to keep track of a separate pointer * into each buffer; it uses a single pointer which increments by 1 for * each vertex. So we use SVBI0 for this pointer, regardless of whether * transform feedback is in interleaved or separate attribs mode. * * Make sure that the buffers have enough room for all the vertices. */ brw_ADD(p, get_element_ud(c->reg.temp, 0), get_element_ud(c->reg.SVBI, 0), brw_imm_ud(num_verts)); brw_CMP(p, vec1(brw_null_reg()), BRW_CONDITIONAL_LE, get_element_ud(c->reg.temp, 0), get_element_ud(c->reg.SVBI, 4)); brw_IF(p, BRW_EXECUTE_1); /* Compute the destination indices to write to. Usually we use SVBI[0] * + (0, 1, 2). However, for odd-numbered triangles in tristrips, the * vertices come down the pipeline in reversed winding order, so we need * to flip the order when writing to the transform feedback buffer. To * ensure that flatshading accuracy is preserved, we need to write them * in order SVBI[0] + (0, 2, 1) if we're using the first provoking * vertex convention, and in order SVBI[0] + (1, 0, 2) if we're using * the last provoking vertex convention. * * Note: since brw_imm_v can only be used in instructions in * packed-word execution mode, and SVBI is a double-word, we need to * first move the appropriate immediate constant ((0, 1, 2), (0, 2, 1), * or (1, 0, 2)) to the destination_indices register, and then add SVBI * using a separate instruction. Also, since the immediate constant is * expressed as packed words, and we need to load double-words into * destination_indices, we need to intersperse zeros to fill the upper * halves of each double-word. */ brw_MOV(p, destination_indices_uw, brw_imm_v(0x00020100)); /* (0, 1, 2) */ if (num_verts == 3) { /* Get primitive type into temp register. */ brw_AND(p, get_element_ud(c->reg.temp, 0), get_element_ud(c->reg.R0, 2), brw_imm_ud(0x1f)); /* Test if primitive type is TRISTRIP_REVERSE. We need to do this as * an 8-wide comparison so that the conditional MOV that follows * moves all 8 words correctly. */ brw_CMP(p, vec8(brw_null_reg()), BRW_CONDITIONAL_EQ, get_element_ud(c->reg.temp, 0), brw_imm_ud(_3DPRIM_TRISTRIP_REVERSE)); /* If so, then overwrite destination_indices_uw with the appropriate * reordering. */ inst = brw_MOV(p, destination_indices_uw, brw_imm_v(key->pv_first ? 0x00010200 /* (0, 2, 1) */ : 0x00020001)); /* (1, 0, 2) */ brw_inst_set_pred_control(p->devinfo, inst, BRW_PREDICATE_NORMAL); } assert(c->reg.destination_indices.width == BRW_EXECUTE_4); brw_push_insn_state(p); brw_set_default_exec_size(p, BRW_EXECUTE_4); brw_ADD(p, c->reg.destination_indices, c->reg.destination_indices, get_element_ud(c->reg.SVBI, 0)); brw_pop_insn_state(p); /* For each vertex, generate code to output each varying using the * appropriate binding table entry. */ for (vertex = 0; vertex < num_verts; ++vertex) { /* Set up the correct destination index for this vertex */ brw_MOV(p, get_element_ud(c->reg.header, 5), get_element_ud(c->reg.destination_indices, vertex)); for (binding = 0; binding < key->num_transform_feedback_bindings; ++binding) { unsigned char varying = key->transform_feedback_bindings[binding]; unsigned char slot = c->vue_map.varying_to_slot[varying]; /* From the Sandybridge PRM, Volume 2, Part 1, Section 4.5.1: * * "Prior to End of Thread with a URB_WRITE, the kernel must * ensure that all writes are complete by sending the final * write as a committed write." */ bool final_write = binding == key->num_transform_feedback_bindings - 1 && vertex == num_verts - 1; struct brw_reg vertex_slot = c->reg.vertex[vertex]; vertex_slot.nr += slot / 2; vertex_slot.subnr = (slot % 2) * 16; /* gl_PointSize is stored in VARYING_SLOT_PSIZ.w. */ vertex_slot.swizzle = varying == VARYING_SLOT_PSIZ ? BRW_SWIZZLE_WWWW : key->transform_feedback_swizzles[binding]; brw_set_default_access_mode(p, BRW_ALIGN_16); brw_push_insn_state(p); brw_set_default_exec_size(p, BRW_EXECUTE_4); brw_MOV(p, stride(c->reg.header, 4, 4, 1), retype(vertex_slot, BRW_REGISTER_TYPE_UD)); brw_pop_insn_state(p); brw_set_default_access_mode(p, BRW_ALIGN_1); brw_svb_write(p, final_write ? c->reg.temp : brw_null_reg(), /* dest */ 1, /* msg_reg_nr */ c->reg.header, /* src0 */ SURF_INDEX_GEN6_SOL_BINDING(binding), /* binding_table_index */ final_write); /* send_commit_msg */ } } brw_ENDIF(p); /* Now, reinitialize the header register from R0 to restore the parts of * the register that we overwrote while streaming out transform feedback * data. */ brw_ff_gs_initialize_header(c); /* Finally, wait for the write commit to occur so that we can proceed to * other things safely. * * From the Sandybridge PRM, Volume 4, Part 1, Section 3.3: * * The write commit does not modify the destination register, but * merely clears the dependency associated with the destination * register. Thus, a simple “mov” instruction using the register as a * source is sufficient to wait for the write commit to occur. */ brw_MOV(p, c->reg.temp, c->reg.temp); } brw_ff_gs_ff_sync(c, 1); brw_ff_gs_overwrite_header_dw2_from_r0(c); switch (num_verts) { case 1: brw_ff_gs_offset_header_dw2(c, URB_WRITE_PRIM_START | URB_WRITE_PRIM_END); brw_ff_gs_emit_vue(c, c->reg.vertex[0], true); break; case 2: brw_ff_gs_offset_header_dw2(c, URB_WRITE_PRIM_START); brw_ff_gs_emit_vue(c, c->reg.vertex[0], false); brw_ff_gs_offset_header_dw2(c, URB_WRITE_PRIM_END - URB_WRITE_PRIM_START); brw_ff_gs_emit_vue(c, c->reg.vertex[1], true); break; case 3: if (check_edge_flags) { /* Only emit vertices 0 and 1 if this is the first triangle of the * polygon. Otherwise they are redundant. */ brw_AND(p, retype(brw_null_reg(), BRW_REGISTER_TYPE_UD), get_element_ud(c->reg.R0, 2), brw_imm_ud(BRW_GS_EDGE_INDICATOR_0)); brw_inst_set_cond_modifier(p->devinfo, brw_last_inst, BRW_CONDITIONAL_NZ); brw_IF(p, BRW_EXECUTE_1); } brw_ff_gs_offset_header_dw2(c, URB_WRITE_PRIM_START); brw_ff_gs_emit_vue(c, c->reg.vertex[0], false); brw_ff_gs_offset_header_dw2(c, -URB_WRITE_PRIM_START); brw_ff_gs_emit_vue(c, c->reg.vertex[1], false); if (check_edge_flags) { brw_ENDIF(p); /* Only emit vertex 2 in PRIM_END mode if this is the last triangle * of the polygon. Otherwise leave the primitive incomplete because * there are more polygon vertices coming. */ brw_AND(p, retype(brw_null_reg(), BRW_REGISTER_TYPE_UD), get_element_ud(c->reg.R0, 2), brw_imm_ud(BRW_GS_EDGE_INDICATOR_1)); brw_inst_set_cond_modifier(p->devinfo, brw_last_inst, BRW_CONDITIONAL_NZ); brw_set_default_predicate_control(p, BRW_PREDICATE_NORMAL); } brw_ff_gs_offset_header_dw2(c, URB_WRITE_PRIM_END); brw_set_default_predicate_control(p, BRW_PREDICATE_NONE); brw_ff_gs_emit_vue(c, c->reg.vertex[2], true); break; } }