From af0cc743e607293146861518bb6ef96f411aeca9 Mon Sep 17 00:00:00 2001 From: Francisco Jerez Date: Thu, 21 Jul 2016 20:25:28 -0700 Subject: [PATCH] i965/fs: Implement non-coherent framebuffer fetch using the sampler unit. v2: Memoize sample ID, misc codestyle changes. (Ken) Reviewed-by: Kenneth Graunke --- src/mesa/drivers/dri/i965/brw_fs.h | 2 + src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 92 ++++++++++++++++++++++++ 2 files changed, 94 insertions(+) diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h index 86e85db24ab..7819f1ca3c0 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.h +++ b/src/mesa/drivers/dri/i965/brw_fs.h @@ -244,6 +244,8 @@ public: fs_reg color1, fs_reg color2, fs_reg src0_alpha, unsigned components); void emit_fb_writes(); + fs_inst *emit_non_coherent_fb_read(const brw::fs_builder &bld, + const fs_reg &dst, unsigned target); void emit_urb_writes(const fs_reg &gs_vertex_count = fs_reg()); void set_gs_stream_control_data_bits(const fs_reg &vertex_count, unsigned stream_id); diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp index d01c4b08052..e63ea24b2fd 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp @@ -3155,6 +3155,98 @@ fs_visitor::nir_emit_gs_intrinsic(const fs_builder &bld, } } +/** + * Fetch the current render target layer index. + */ +static fs_reg +fetch_render_target_array_index(const fs_builder &bld) +{ + if (bld.shader->devinfo->gen >= 6) { + /* The render target array index is provided in the thread payload as + * bits 26:16 of r0.0. + */ + const fs_reg idx = bld.vgrf(BRW_REGISTER_TYPE_UD); + bld.AND(idx, brw_uw1_reg(BRW_GENERAL_REGISTER_FILE, 0, 1), + brw_imm_uw(0x7ff)); + return idx; + } else { + /* Pre-SNB we only ever render into the first layer of the framebuffer + * since layered rendering is not implemented. + */ + return brw_imm_ud(0); + } +} + +/** + * Fake non-coherent framebuffer read implemented using TXF to fetch from the + * framebuffer at the current fragment coordinates and sample index. + */ +fs_inst * +fs_visitor::emit_non_coherent_fb_read(const fs_builder &bld, const fs_reg &dst, + unsigned target) +{ + const struct brw_device_info *devinfo = bld.shader->devinfo; + + assert(bld.shader->stage == MESA_SHADER_FRAGMENT); + const brw_wm_prog_key *wm_key = + reinterpret_cast(key); + assert(!wm_key->coherent_fb_fetch); + const brw_wm_prog_data *wm_prog_data = + reinterpret_cast(stage_prog_data); + + /* Calculate the surface index relative to the start of the texture binding + * table block, since that's what the texturing messages expect. + */ + const unsigned surface = target + + wm_prog_data->binding_table.render_target_read_start - + wm_prog_data->base.binding_table.texture_start; + + brw_mark_surface_used( + bld.shader->stage_prog_data, + wm_prog_data->binding_table.render_target_read_start + target); + + /* Calculate the fragment coordinates. */ + const fs_reg coords = bld.vgrf(BRW_REGISTER_TYPE_UD, 3); + bld.MOV(offset(coords, bld, 0), pixel_x); + bld.MOV(offset(coords, bld, 1), pixel_y); + bld.MOV(offset(coords, bld, 2), fetch_render_target_array_index(bld)); + + /* Calculate the sample index and MCS payload when multisampling. Luckily + * the MCS fetch message behaves deterministically for UMS surfaces, so it + * shouldn't be necessary to recompile based on whether the framebuffer is + * CMS or UMS. + */ + if (wm_key->multisample_fbo && + nir_system_values[SYSTEM_VALUE_SAMPLE_ID].file == BAD_FILE) + nir_system_values[SYSTEM_VALUE_SAMPLE_ID] = *emit_sampleid_setup(); + + const fs_reg sample = nir_system_values[SYSTEM_VALUE_SAMPLE_ID]; + const fs_reg mcs = wm_key->multisample_fbo ? + emit_mcs_fetch(coords, 3, brw_imm_ud(surface)) : fs_reg(); + + /* Use either a normal or a CMS texel fetch message depending on whether + * the framebuffer is single or multisample. On SKL+ use the wide CMS + * message just in case the framebuffer uses 16x multisampling, it should + * be equivalent to the normal CMS fetch for lower multisampling modes. + */ + const opcode op = !wm_key->multisample_fbo ? SHADER_OPCODE_TXF_LOGICAL : + devinfo->gen >= 9 ? SHADER_OPCODE_TXF_CMS_W_LOGICAL : + SHADER_OPCODE_TXF_CMS_LOGICAL; + + /* Emit the instruction. */ + const fs_reg srcs[] = { coords, fs_reg(), brw_imm_ud(0), fs_reg(), + sample, mcs, + brw_imm_ud(surface), brw_imm_ud(0), + fs_reg(), brw_imm_ud(3), brw_imm_ud(0) }; + STATIC_ASSERT(ARRAY_SIZE(srcs) == TEX_LOGICAL_NUM_SRCS); + + fs_inst *inst = bld.emit(op, dst, srcs, ARRAY_SIZE(srcs)); + inst->regs_written = 4 * inst->dst.component_size(inst->exec_size) / + REG_SIZE; + + return inst; +} + void fs_visitor::nir_emit_fs_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr) -- 2.30.2