diff options
| -rw-r--r-- | src/compiler/nir/meson.build | 1 | ||||
| -rw-r--r-- | src/compiler/nir/nir.h | 1 | ||||
| -rw-r--r-- | src/compiler/nir/nir_lower_clip_disable.c | 131 |
3 files changed, 133 insertions, 0 deletions
diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build index 20260d0d5e6..2ca803563d6 100644 --- a/src/compiler/nir/meson.build +++ b/src/compiler/nir/meson.build @@ -125,6 +125,7 @@ files_libnir = files( 'nir_lower_clamp_color_outputs.c', 'nir_lower_clip.c', 'nir_lower_clip_cull_distance_arrays.c', + 'nir_lower_clip_disable.c', 'nir_lower_clip_halfz.c', 'nir_lower_variable_initializers.c', 'nir_lower_discard_to_demote.c', diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 463e5468fc2..c90b025f0a8 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -4357,6 +4357,7 @@ bool nir_lower_clip_gs(nir_shader *shader, unsigned ucp_enables, bool nir_lower_clip_fs(nir_shader *shader, unsigned ucp_enables, bool use_clipdist_array); bool nir_lower_clip_cull_distance_arrays(nir_shader *nir); +bool nir_lower_clip_disable(nir_shader *shader, unsigned clip_plane_enable); void nir_lower_point_size_mov(nir_shader *shader, const gl_state_index16 *pointsize_state_tokens); diff --git a/src/compiler/nir/nir_lower_clip_disable.c b/src/compiler/nir/nir_lower_clip_disable.c new file mode 100644 index 00000000000..2925d033bd0 --- /dev/null +++ b/src/compiler/nir/nir_lower_clip_disable.c @@ -0,0 +1,131 @@ +/* + * Copyright © 2020 Mike Blumenkrantz + * + * 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: + * Mike Blumenkrantz <[email protected]> + */ + +#include "nir.h" +#include "nir_builder.h" + + +/** + * This pass uses the enabled clip planes from the rasterizer state to rewrite + * vertex shader store operations and store an undef to the corresponding gl_ClipDistance[n] + * value if the plane is disabled + */ + +/* recursively nest if/else blocks until we get to an array index, + * then overwrite it if that plane isn't enabled + */ +static void +recursive_if_chain(nir_builder *b, nir_deref_instr *deref, nir_ssa_def *value, unsigned clip_plane_enable, nir_ssa_def *index, unsigned start, unsigned end) +{ + if (start == end - 1) { + /* store the original value again if the clip plane is enabled */ + if (clip_plane_enable & (1 << start)) + nir_store_deref(b, deref, value, 1 << start); + else + nir_store_deref(b, deref, nir_ssa_undef(b, 1, 32), 1 << start); + return; + } + + unsigned mid = start + (end - start) / 2; + nir_push_if(b, nir_ilt(b, index, nir_imm_int(b, mid))); + recursive_if_chain(b, deref, value, clip_plane_enable, index, start, mid); + nir_push_else(b, NULL); + recursive_if_chain(b, deref, value, clip_plane_enable, index, mid, end); + nir_pop_if(b, NULL); +} + +/* vulkan (and some drivers) provides no concept of enabling clip planes through api, + * so we rewrite disabled clip planes to an undefined value in order to disable them + */ +static bool +lower_clip_plane_store(nir_intrinsic_instr *instr, unsigned clip_plane_enable, nir_builder *b) +{ + nir_variable *out; + unsigned plane; + + if (instr->intrinsic != nir_intrinsic_store_deref) + return false; + + nir_deref_instr *deref = nir_src_as_deref(instr->src[0]); + + out = nir_deref_instr_get_variable(deref); + if ((out->data.location != VARYING_SLOT_CLIP_DIST0) || + out->data.mode != nir_var_shader_out) + return false; + + b->cursor = nir_after_instr(&instr->instr); + if (nir_src_is_const(deref->arr.index)) { + /* storing using a constant index */ + plane = nir_src_as_uint(deref->arr.index); + /* no need to make changes if the clip plane is enabled */ + if (clip_plane_enable & (1 << plane)) + return false; + + nir_store_deref(b, deref, nir_ssa_undef(b, 1, 32), 1 << plane); + } else { + /* storing using a variable index */ + nir_ssa_def *index = nir_ssa_for_src(b, deref->arr.index, 1); + unsigned length = glsl_get_length(nir_deref_instr_parent(deref)->type); + + recursive_if_chain(b, deref, instr->src[1].ssa, clip_plane_enable, index, 0, length); + } + nir_instr_remove(&instr->instr); + return true; +} + +bool +nir_lower_clip_disable(nir_shader *shader, unsigned clip_plane_enable) +{ + bool progress = false; + + nir_foreach_variable(var, &shader->outputs) { + if (var->data.location == VARYING_SLOT_CLIP_DIST0) { + unsigned size = glsl_get_length(var->type); + /* if currently-enabled planes match used planes then no-op */ + if (clip_plane_enable == (1u << size) - 1) + return false; + } + } + + nir_foreach_function(function, shader) { + if (function->impl) { + nir_builder builder; + nir_builder_init(&builder, function->impl); + nir_foreach_block(block, function->impl) { + nir_foreach_instr_safe(instr, block) { + if (instr->type == nir_instr_type_intrinsic) + progress |= lower_clip_plane_store(nir_instr_as_intrinsic(instr), + clip_plane_enable, + &builder); + } + } + + nir_metadata_preserve(function->impl, nir_metadata_block_index | nir_metadata_dominance); + } + } + + return progress; +} |