| /* |
| * Copyright © 2015 Red Hat |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| * |
| * Authors: |
| * Rob Clark <robclark@freedesktop.org> |
| */ |
| |
| #include "nir.h" |
| #include "nir_builder.h" |
| |
| #define MAX_CLIP_PLANES 8 |
| |
| /* Generates the lowering code for user-clip-planes, generating CLIPDIST |
| * from UCP[n] + CLIPVERTEX or POSITION. Additionally, an optional pass |
| * for fragment shaders to insert conditional kills based on the inter- |
| * polated CLIPDIST |
| * |
| * NOTE: should be run after nir_lower_io_var_to_temporaries() (or at |
| * least in scenarios where you can count on each output written once |
| * and only once). |
| */ |
| |
| static nir_variable * |
| create_clipdist_var(nir_shader *shader, |
| bool output, gl_varying_slot slot, unsigned array_size) |
| { |
| nir_variable *var = rzalloc(shader, nir_variable); |
| |
| if (output) { |
| var->data.driver_location = shader->num_outputs; |
| var->data.mode = nir_var_shader_out; |
| shader->num_outputs += MAX2(1, DIV_ROUND_UP(array_size, 4)); |
| } else { |
| var->data.driver_location = shader->num_inputs; |
| var->data.mode = nir_var_shader_in; |
| shader->num_inputs += MAX2(1, DIV_ROUND_UP(array_size, 4)); |
| } |
| var->name = ralloc_asprintf(var, "clipdist_%d", slot - VARYING_SLOT_CLIP_DIST0); |
| var->data.index = 0; |
| var->data.location = slot; |
| |
| if (array_size > 0) { |
| var->type = glsl_array_type(glsl_float_type(), array_size, |
| sizeof(float)); |
| var->data.compact = 1; |
| } else |
| var->type = glsl_vec4_type(); |
| |
| nir_shader_add_variable(shader, var); |
| return var; |
| } |
| |
| static void |
| create_clipdist_vars(nir_shader *shader, nir_variable **io_vars, |
| unsigned ucp_enables, bool output, |
| bool use_clipdist_array) |
| { |
| if (use_clipdist_array) { |
| io_vars[0] = |
| create_clipdist_var(shader, output, |
| VARYING_SLOT_CLIP_DIST0, |
| shader->info.clip_distance_array_size); |
| } else { |
| if (ucp_enables & 0x0f) |
| io_vars[0] = |
| create_clipdist_var(shader, output, |
| VARYING_SLOT_CLIP_DIST0, 0); |
| if (ucp_enables & 0xf0) |
| io_vars[1] = |
| create_clipdist_var(shader, output, |
| VARYING_SLOT_CLIP_DIST1, 0); |
| } |
| } |
| |
| static void |
| store_clipdist_output(nir_builder *b, nir_variable *out, int location, int location_offset, |
| nir_def **val, bool use_clipdist_array) |
| { |
| unsigned num_slots = b->shader->info.clip_distance_array_size; |
| nir_io_semantics semantics = { |
| .location = location, |
| .num_slots = b->shader->options->compact_arrays ? num_slots : 1, |
| }; |
| |
| if (location == VARYING_SLOT_CLIP_DIST1 || location_offset) |
| num_slots -= 4; |
| else |
| num_slots = MIN2(num_slots, 4); |
| for (unsigned i = 0; i < num_slots; i++) { |
| nir_store_output(b, |
| val[i] ? val[i] : nir_imm_zero(b, 1, 32), |
| nir_imm_int(b, location_offset), |
| .write_mask = 0x1, |
| .component = i, |
| .io_semantics = semantics, |
| .base = out ? out->data.driver_location : 0); |
| } |
| } |
| |
| static void |
| load_clipdist_input(nir_builder *b, nir_variable *in, int location_offset, |
| nir_def **val, bool use_load_interp) |
| { |
| nir_def *load; |
| if (use_load_interp) { |
| /* TODO: use sample when per-sample shading? */ |
| nir_def *barycentric = nir_load_barycentric( |
| b, nir_intrinsic_load_barycentric_pixel, INTERP_MODE_NONE); |
| load = nir_load_interpolated_input( |
| b, 4, 32, barycentric, nir_imm_int(b, location_offset), |
| .base = in->data.driver_location, |
| .io_semantics.location = in->data.location); |
| |
| } else { |
| load = nir_load_input(b, 4, 32, nir_imm_int(b, location_offset), |
| .base = in->data.driver_location, |
| .io_semantics.location = in->data.location); |
| } |
| |
| val[0] = nir_channel(b, load, 0); |
| val[1] = nir_channel(b, load, 1); |
| val[2] = nir_channel(b, load, 2); |
| val[3] = nir_channel(b, load, 3); |
| } |
| |
| static nir_def * |
| find_output(nir_builder *b, unsigned location) |
| { |
| nir_def *comp[4] = { NULL }; |
| |
| nir_foreach_function_impl(impl, b->shader) { |
| nir_foreach_block(block, impl) { |
| nir_foreach_instr_safe(instr, block) { |
| if (instr->type != nir_instr_type_intrinsic) |
| continue; |
| |
| nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); |
| |
| if ((intr->intrinsic == nir_intrinsic_store_output || |
| intr->intrinsic == nir_intrinsic_store_per_vertex_output || |
| intr->intrinsic == nir_intrinsic_store_per_view_output || |
| intr->intrinsic == nir_intrinsic_store_per_primitive_output) && |
| nir_intrinsic_io_semantics(intr).location == location) { |
| assert(nir_src_is_const(*nir_get_io_offset_src(intr))); |
| unsigned component = nir_intrinsic_component(intr); |
| unsigned wrmask = nir_intrinsic_write_mask(intr); |
| |
| u_foreach_bit(i, wrmask) { |
| unsigned index = component + i; |
| |
| /* Each component should be written only once. */ |
| assert(!comp[index]); |
| comp[index] = nir_channel(b, intr->src[0].ssa, i); |
| } |
| |
| /* Remove it because it's going to be replaced by CLIP_DIST. */ |
| if (location == VARYING_SLOT_CLIP_VERTEX) |
| nir_instr_remove(instr); |
| } |
| } |
| } |
| } |
| assert(comp[0] || comp[1] || comp[2] || comp[3]); |
| |
| for (unsigned i = 0; i < 4; i++) { |
| if (!comp[i]) |
| comp[i] = nir_undef(b, 1, 32); |
| } |
| |
| return nir_vec(b, comp, 4); |
| } |
| |
| static bool |
| find_clipvertex_and_position_outputs(nir_shader *shader, |
| nir_variable **clipvertex, |
| nir_variable **position) |
| { |
| if (shader->info.io_lowered) { |
| if (shader->info.outputs_written & (VARYING_BIT_CLIP_DIST0 | VARYING_BIT_CLIP_DIST1)) |
| return false; |
| if (shader->info.outputs_written & (VARYING_BIT_POS | VARYING_BIT_CLIP_VERTEX)) |
| return true; |
| return false; |
| } |
| nir_foreach_shader_out_variable(var, shader) { |
| switch (var->data.location) { |
| case VARYING_SLOT_POS: |
| *position = var; |
| break; |
| case VARYING_SLOT_CLIP_VERTEX: |
| *clipvertex = var; |
| break; |
| case VARYING_SLOT_CLIP_DIST0: |
| case VARYING_SLOT_CLIP_DIST1: |
| /* if shader is already writing CLIPDIST, then |
| * there should be no user-clip-planes to deal |
| * with. |
| * |
| * We assume nir_remove_dead_variables has removed the clipdist |
| * variables if they're not written. |
| */ |
| return false; |
| } |
| } |
| |
| return *clipvertex || *position; |
| } |
| |
| static nir_def * |
| get_ucp(nir_builder *b, int plane, |
| const gl_state_index16 clipplane_state_tokens[][STATE_LENGTH]) |
| { |
| if (clipplane_state_tokens) { |
| char tmp[100]; |
| snprintf(tmp, ARRAY_SIZE(tmp), "gl_ClipPlane%dMESA", plane); |
| nir_variable *var = nir_state_variable_create(b->shader, |
| glsl_vec4_type(), |
| tmp, clipplane_state_tokens[plane]); |
| return nir_load_var(b, var); |
| } else |
| return nir_load_user_clip_plane(b, plane); |
| } |
| |
| static uint64_t |
| update_mask(uint32_t ucp_enables) |
| { |
| uint64_t mask = 0; |
| |
| if (ucp_enables & 0x0f) |
| mask |= VARYING_BIT_CLIP_DIST0; |
| if (ucp_enables & 0xf0) |
| mask |= VARYING_BIT_CLIP_DIST1; |
| |
| return mask; |
| } |
| |
| struct lower_clip_state { |
| nir_variable *position; |
| nir_variable *clipvertex; |
| nir_variable *out[2]; |
| unsigned ucp_enables; |
| bool use_clipdist_array; |
| const gl_state_index16 (*clipplane_state_tokens)[STATE_LENGTH]; |
| |
| /* This holds the current CLIP_VERTEX value for GS. */ |
| nir_variable *clipvertex_gs_temp; |
| }; |
| |
| static void |
| lower_clip_vertex_var(nir_builder *b, const struct lower_clip_state *state) |
| { |
| nir_def *clipdist[MAX_CLIP_PLANES] = { NULL }; |
| nir_def *cv = nir_load_var(b, state->clipvertex ? state->clipvertex |
| : state->position); |
| |
| if (state->clipvertex) { |
| state->clipvertex->data.mode = nir_var_shader_temp; |
| nir_fixup_deref_modes(b->shader); |
| } |
| |
| for (int plane = 0; plane < MAX_CLIP_PLANES; plane++) { |
| if (state->ucp_enables & (1 << plane)) { |
| nir_def *ucp = get_ucp(b, plane, state->clipplane_state_tokens); |
| |
| /* calculate clipdist[plane] - dot(ucp, cv): */ |
| clipdist[plane] = nir_fdot(b, ucp, cv); |
| } else { |
| /* 0.0 == don't-clip == disabled: */ |
| clipdist[plane] = nir_imm_float(b, 0.0); |
| } |
| if (state->use_clipdist_array && |
| plane < util_last_bit(state->ucp_enables)) { |
| nir_deref_instr *deref; |
| deref = nir_build_deref_array_imm(b, |
| nir_build_deref_var(b, state->out[0]), |
| plane); |
| nir_store_deref(b, deref, clipdist[plane], 1); |
| } |
| } |
| |
| if (!state->use_clipdist_array) { |
| if (state->ucp_enables & 0x0f) |
| nir_store_var(b, state->out[0], nir_vec(b, clipdist, 4), 0xf); |
| if (state->ucp_enables & 0xf0) |
| nir_store_var(b, state->out[1], nir_vec(b, &clipdist[4], 4), 0xf); |
| b->shader->info.outputs_written |= update_mask(state->ucp_enables); |
| } |
| } |
| |
| static void |
| lower_clip_vertex_intrin(nir_builder *b, const struct lower_clip_state *state) |
| { |
| nir_def *clipdist[MAX_CLIP_PLANES] = { NULL }; |
| nir_def *cv; |
| |
| if (state->clipvertex_gs_temp) { |
| cv = nir_load_deref(b, nir_build_deref_var(b, state->clipvertex_gs_temp)); |
| } else { |
| cv = find_output(b, b->shader->info.outputs_written & |
| VARYING_BIT_CLIP_VERTEX |
| ? VARYING_SLOT_CLIP_VERTEX |
| : VARYING_SLOT_POS); |
| } |
| |
| for (int plane = 0; plane < MAX_CLIP_PLANES; plane++) { |
| if (state->ucp_enables & (1 << plane)) { |
| nir_def *ucp = get_ucp(b, plane, state->clipplane_state_tokens); |
| |
| /* calculate clipdist[plane] - dot(ucp, cv): */ |
| clipdist[plane] = nir_fdot(b, ucp, cv); |
| } else { |
| /* 0.0 == don't-clip == disabled: */ |
| clipdist[plane] = nir_imm_float(b, 0.0); |
| } |
| } |
| |
| if (state->use_clipdist_array) { |
| /* Always emit the first vec4. */ |
| store_clipdist_output(b, state->out[0], VARYING_SLOT_CLIP_DIST0, 0, |
| &clipdist[0], state->use_clipdist_array); |
| if (state->ucp_enables & 0xf0) { |
| store_clipdist_output(b, state->out[0], VARYING_SLOT_CLIP_DIST0, 1, |
| &clipdist[4], state->use_clipdist_array); |
| } |
| } else { |
| /* Always emit the first vec4. */ |
| store_clipdist_output(b, state->out[0], VARYING_SLOT_CLIP_DIST0, 0, |
| &clipdist[0], state->use_clipdist_array); |
| if (state->ucp_enables & 0xf0) { |
| store_clipdist_output(b, state->out[1], VARYING_SLOT_CLIP_DIST1, 0, |
| &clipdist[4], state->use_clipdist_array); |
| } |
| } |
| b->shader->info.outputs_written |= update_mask(state->ucp_enables); |
| } |
| |
| /* |
| * VS lowering |
| */ |
| |
| /* ucp_enables is bitmask of enabled ucps. Actual ucp values are |
| * passed in to shader via user_clip_plane system-values |
| * |
| * If use_vars is true, the pass will use variable loads and stores instead |
| * of working with store_output intrinsics. |
| * |
| * If use_clipdist_array is true, the pass will use compact arrays for the |
| * clipdist output instead of two vec4s. |
| */ |
| bool |
| nir_lower_clip_vs(nir_shader *shader, unsigned ucp_enables, bool use_vars, |
| bool use_clipdist_array, |
| const gl_state_index16 clipplane_state_tokens[][STATE_LENGTH]) |
| { |
| if (!ucp_enables) |
| return false; |
| |
| nir_function_impl *impl = nir_shader_get_entrypoint(shader); |
| nir_builder b = nir_builder_create(impl); |
| |
| /* NIR should ensure that, even in case of loops/if-else, there |
| * should be only a single predecessor block to end_block, which |
| * makes the perfect place to insert the clipdist calculations. |
| * |
| * NOTE: in case of early returns, these would have to be lowered |
| * to jumps to end_block predecessor in a previous pass. Not sure |
| * if there is a good way to sanity check this, but for now the |
| * users of this pass don't support sub-routines. |
| */ |
| assert(impl->end_block->predecessors->entries == 1); |
| b.cursor = nir_after_impl(impl); |
| |
| struct lower_clip_state state = { NULL }; |
| state.ucp_enables = ucp_enables; |
| state.use_clipdist_array = use_clipdist_array; |
| state.clipplane_state_tokens = clipplane_state_tokens; |
| |
| /* find clipvertex/position outputs */ |
| if (!find_clipvertex_and_position_outputs(shader, &state.clipvertex, |
| &state.position)) |
| return false; |
| |
| shader->info.clip_distance_array_size = util_last_bit(ucp_enables); |
| |
| if (!use_vars || shader->info.io_lowered) { |
| /* If the driver has lowered IO instead of st/mesa, the driver expects |
| * that variables are present even with lowered IO, so create them. |
| */ |
| if (!shader->info.io_lowered) { |
| create_clipdist_vars(shader, state.out, ucp_enables, true, |
| use_clipdist_array); |
| } |
| |
| lower_clip_vertex_intrin(&b, &state); |
| } else { |
| create_clipdist_vars(shader, state.out, ucp_enables, true, |
| use_clipdist_array); |
| lower_clip_vertex_var(&b, &state); |
| } |
| |
| return nir_progress(true, impl, nir_metadata_dominance); |
| } |
| |
| /* |
| * GS lowering |
| */ |
| |
| static bool |
| lower_clip_vertex_gs(nir_builder *b, nir_intrinsic_instr *intr, void *opaque) |
| { |
| const struct lower_clip_state *state = |
| (const struct lower_clip_state *)opaque; |
| |
| switch (intr->intrinsic) { |
| case nir_intrinsic_emit_vertex_with_counter: |
| case nir_intrinsic_emit_vertex: |
| b->cursor = nir_before_instr(&intr->instr); |
| if (b->shader->info.io_lowered) |
| lower_clip_vertex_intrin(b, state); |
| else |
| lower_clip_vertex_var(b, state); |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| /* Track the CLIP_VERTEX or POS value in a local variable, so that we can |
| * retrieve it at emit_vertex. |
| */ |
| static bool |
| save_clipvertex_to_temp_gs(nir_builder *b, nir_intrinsic_instr *intr, |
| void *opaque) |
| { |
| const struct lower_clip_state *state = |
| (const struct lower_clip_state *)opaque; |
| gl_varying_slot clip_output_slot = |
| b->shader->info.outputs_written & VARYING_BIT_CLIP_VERTEX ? VARYING_SLOT_CLIP_VERTEX : VARYING_SLOT_POS; |
| |
| if (intr->intrinsic != nir_intrinsic_store_output || |
| nir_intrinsic_io_semantics(intr).location != clip_output_slot) |
| return false; |
| |
| b->cursor = nir_before_instr(&intr->instr); |
| |
| unsigned component = nir_intrinsic_component(intr); |
| unsigned writemask = nir_intrinsic_write_mask(intr); |
| nir_def *value = intr->src[0].ssa; |
| |
| /* Shift vector elements to the right by component. */ |
| if (component) { |
| unsigned swizzle[4] = { 0 }; |
| |
| for (unsigned i = 1; i < value->num_components; i++) |
| swizzle[component + i] = i; |
| value = nir_swizzle(b, value, swizzle, |
| component + value->num_components); |
| } |
| |
| nir_store_deref(b, nir_build_deref_var(b, state->clipvertex_gs_temp), |
| nir_pad_vec4(b, value), writemask << component); |
| |
| /* Remove the CLIP_VERTEX store because it will be replaced by CLIP_DIST |
| * stores. |
| */ |
| if (clip_output_slot == VARYING_SLOT_CLIP_VERTEX) |
| nir_instr_remove(&intr->instr); |
| return true; |
| } |
| |
| bool |
| nir_lower_clip_gs(nir_shader *shader, unsigned ucp_enables, |
| bool use_clipdist_array, |
| const gl_state_index16 clipplane_state_tokens[][STATE_LENGTH]) |
| { |
| if (!ucp_enables) |
| return false; |
| |
| struct lower_clip_state state = { NULL }; |
| state.ucp_enables = ucp_enables; |
| state.use_clipdist_array = use_clipdist_array; |
| state.clipplane_state_tokens = clipplane_state_tokens; |
| |
| /* find clipvertex/position outputs */ |
| if (!find_clipvertex_and_position_outputs(shader, &state.clipvertex, |
| &state.position)) |
| return false; |
| |
| shader->info.clip_distance_array_size = util_last_bit(ucp_enables); |
| |
| if (shader->info.io_lowered) { |
| /* Track the current value of CLIP_VERTEX or POS in a local variable. */ |
| state.clipvertex_gs_temp = |
| nir_local_variable_create(nir_shader_get_entrypoint(shader), |
| glsl_vec4_type(), "clipvertex_gs_temp"); |
| if (!nir_shader_intrinsics_pass(shader, save_clipvertex_to_temp_gs, |
| nir_metadata_control_flow, &state)) |
| return false; |
| } else { |
| /* insert CLIPDIST outputs */ |
| create_clipdist_vars(shader, state.out, ucp_enables, true, |
| use_clipdist_array); |
| } |
| |
| nir_shader_intrinsics_pass(shader, lower_clip_vertex_gs, |
| nir_metadata_control_flow, &state); |
| return true; |
| } |
| |
| /* |
| * FS lowering |
| */ |
| |
| static void |
| lower_clip_fs(nir_function_impl *impl, unsigned ucp_enables, |
| nir_variable **in, bool use_clipdist_array, bool use_load_interp) |
| { |
| nir_def *clipdist[MAX_CLIP_PLANES]; |
| nir_builder b = nir_builder_at(nir_before_impl(impl)); |
| |
| if (!use_clipdist_array) { |
| if (ucp_enables & 0x0f) |
| load_clipdist_input(&b, in[0], 0, &clipdist[0], use_load_interp); |
| if (ucp_enables & 0xf0) |
| load_clipdist_input(&b, in[1], 0, &clipdist[4], use_load_interp); |
| } else { |
| if (ucp_enables & 0x0f) |
| load_clipdist_input(&b, in[0], 0, &clipdist[0], use_load_interp); |
| if (ucp_enables & 0xf0) |
| load_clipdist_input(&b, in[0], 1, &clipdist[4], use_load_interp); |
| } |
| b.shader->info.inputs_read |= update_mask(ucp_enables); |
| |
| nir_def *cond = NULL; |
| |
| for (int plane = 0; plane < MAX_CLIP_PLANES; plane++) { |
| if (ucp_enables & (1 << plane)) { |
| nir_def *this_cond = |
| nir_flt_imm(&b, clipdist[plane], 0.0); |
| |
| cond = cond ? nir_ior(&b, cond, this_cond) : this_cond; |
| } |
| } |
| |
| if (cond != NULL) { |
| nir_discard_if(&b, cond); |
| b.shader->info.fs.uses_discard = true; |
| } |
| |
| nir_progress(true, impl, nir_metadata_dominance); |
| } |
| |
| static bool |
| fs_has_clip_dist_input_var(nir_shader *shader, nir_variable **io_vars, |
| unsigned *ucp_enables) |
| { |
| assert(shader->info.stage == MESA_SHADER_FRAGMENT); |
| nir_foreach_shader_in_variable(var, shader) { |
| switch (var->data.location) { |
| case VARYING_SLOT_CLIP_DIST0: |
| assert(var->data.compact); |
| io_vars[0] = var; |
| *ucp_enables &= (1 << glsl_get_length(var->type)) - 1; |
| return true; |
| default: |
| break; |
| } |
| } |
| return false; |
| } |
| |
| /* insert conditional kill based on interpolated CLIPDIST |
| */ |
| bool |
| nir_lower_clip_fs(nir_shader *shader, unsigned ucp_enables, |
| bool use_clipdist_array, bool use_load_interp) |
| { |
| nir_variable *in[2] = { 0 }; |
| |
| if (!ucp_enables) |
| return false; |
| |
| /* this is probably broken until https://gitlab.freedesktop.org/mesa/mesa/-/issues/10826 is fixed */ |
| assert(!shader->info.io_lowered); |
| shader->info.clip_distance_array_size = util_last_bit(ucp_enables); |
| |
| /* No hard reason to require use_clipdist_arr to work with |
| * frag-shader-based gl_ClipDistance, except that the only user that does |
| * not enable this does not support GL 3.0 (or EXT_clip_cull_distance). |
| */ |
| if (!fs_has_clip_dist_input_var(shader, in, &ucp_enables)) |
| create_clipdist_vars(shader, in, ucp_enables, false, use_clipdist_array); |
| else |
| assert(use_clipdist_array); |
| |
| nir_foreach_function_with_impl(function, impl, shader) { |
| if (!strcmp(function->name, "main")) { |
| lower_clip_fs(impl, ucp_enables, in, use_clipdist_array, |
| use_load_interp); |
| } |
| } |
| |
| return true; |
| } |
