diff options
Diffstat (limited to 'src/compiler/nir/nir_opt_dce.c')
| -rw-r--r-- | src/compiler/nir/nir_opt_dce.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_opt_dce.c b/src/compiler/nir/nir_opt_dce.c new file mode 100644 index 0000000..32436c1 --- /dev/null +++ b/src/compiler/nir/nir_opt_dce.c @@ -0,0 +1,183 @@ +/* + * Copyright © 2014 Intel Corporation + * + * 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: + * Connor Abbott (cwabbott0@gmail.com) + * + */ + +#include "nir.h" + +/* SSA-based mark-and-sweep dead code elimination */ + +typedef struct { + struct exec_node node; + nir_instr *instr; +} worklist_elem; + +static void +worklist_push(struct exec_list *worklist, nir_instr *instr) +{ + worklist_elem *elem = ralloc(worklist, worklist_elem); + elem->instr = instr; + instr->pass_flags = 1; + exec_list_push_tail(worklist, &elem->node); +} + +static nir_instr * +worklist_pop(struct exec_list *worklist) +{ + struct exec_node *node = exec_list_pop_head(worklist); + worklist_elem *elem = exec_node_data(worklist_elem, node, node); + return elem->instr; +} + +static bool +mark_live_cb(nir_src *src, void *_state) +{ + struct exec_list *worklist = (struct exec_list *) _state; + + if (src->is_ssa && !src->ssa->parent_instr->pass_flags) { + worklist_push(worklist, src->ssa->parent_instr); + } + + return true; +} + +static void +init_instr(nir_instr *instr, struct exec_list *worklist) +{ + nir_alu_instr *alu_instr; + nir_intrinsic_instr *intrin_instr; + nir_tex_instr *tex_instr; + + /* We use the pass_flags to store the live/dead information. In DCE, we + * just treat it as a zero/non-zerl boolean for whether or not the + * instruction is live. + */ + instr->pass_flags = 0; + + switch (instr->type) { + case nir_instr_type_call: + case nir_instr_type_jump: + worklist_push(worklist, instr); + break; + + case nir_instr_type_alu: + alu_instr = nir_instr_as_alu(instr); + if (!alu_instr->dest.dest.is_ssa) + worklist_push(worklist, instr); + break; + + case nir_instr_type_intrinsic: + intrin_instr = nir_instr_as_intrinsic(instr); + if (nir_intrinsic_infos[intrin_instr->intrinsic].flags & + NIR_INTRINSIC_CAN_ELIMINATE) { + if (nir_intrinsic_infos[intrin_instr->intrinsic].has_dest && + !intrin_instr->dest.is_ssa) { + worklist_push(worklist, instr); + } + } else { + worklist_push(worklist, instr); + } + break; + + case nir_instr_type_tex: + tex_instr = nir_instr_as_tex(instr); + if (!tex_instr->dest.is_ssa) + worklist_push(worklist, instr); + break; + + default: + break; + } +} + +static bool +init_block_cb(nir_block *block, void *_state) +{ + struct exec_list *worklist = (struct exec_list *) _state; + + nir_foreach_instr(block, instr) + init_instr(instr, worklist); + + nir_if *following_if = nir_block_get_following_if(block); + if (following_if) { + if (following_if->condition.is_ssa && + !following_if->condition.ssa->parent_instr->pass_flags) + worklist_push(worklist, following_if->condition.ssa->parent_instr); + } + + return true; +} + +static bool +delete_block_cb(nir_block *block, void *_state) +{ + bool *progress = (bool *) _state; + + nir_foreach_instr_safe(block, instr) { + if (!instr->pass_flags) { + nir_instr_remove(instr); + *progress = true; + } + } + + return true; +} + +static bool +nir_opt_dce_impl(nir_function_impl *impl) +{ + struct exec_list *worklist = ralloc(NULL, struct exec_list); + exec_list_make_empty(worklist); + + nir_foreach_block(impl, init_block_cb, worklist); + + while (!exec_list_is_empty(worklist)) { + nir_instr *instr = worklist_pop(worklist); + nir_foreach_src(instr, mark_live_cb, worklist); + } + + ralloc_free(worklist); + + bool progress = false; + nir_foreach_block(impl, delete_block_cb, &progress); + + if (progress) + nir_metadata_preserve(impl, nir_metadata_block_index | + nir_metadata_dominance); + + return progress; +} + +bool +nir_opt_dce(nir_shader *shader) +{ + bool progress = false; + nir_foreach_function(shader, function) { + if (function->impl && nir_opt_dce_impl(function->impl)) + progress = true; + } + + return progress; +} |