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Diffstat (limited to 'src/glsl/nir/nir_dominance.c')
-rw-r--r-- | src/glsl/nir/nir_dominance.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/src/glsl/nir/nir_dominance.c b/src/glsl/nir/nir_dominance.c new file mode 100644 index 00000000000..988a3fc7450 --- /dev/null +++ b/src/glsl/nir/nir_dominance.c @@ -0,0 +1,300 @@ +/* + * 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" + +/* + * Implements the algorithms for computing the dominance tree and the + * dominance frontier from "A Simple, Fast Dominance Algorithm" by Cooper, + * Harvey, and Kennedy. + */ + +typedef struct { + nir_function_impl *impl; + bool progress; +} dom_state; + +static bool +init_block_cb(nir_block *block, void *_state) +{ + dom_state *state = (dom_state *) _state; + if (block == state->impl->start_block) + block->imm_dom = block; + else + block->imm_dom = NULL; + block->num_dom_children = 0; + + struct set_entry *entry; + set_foreach(block->dom_frontier, entry) { + _mesa_set_remove(block->dom_frontier, entry); + } + + return true; +} + +static nir_block * +intersect(nir_block *b1, nir_block *b2) +{ + while (b1 != b2) { + /* + * Note, the comparisons here are the opposite of what the paper says + * because we index blocks from beginning -> end (i.e. reverse + * post-order) instead of post-order like they assume. + */ + while (b1->index > b2->index) + b1 = b1->imm_dom; + while (b2->index > b1->index) + b2 = b2->imm_dom; + } + + return b1; +} + +static bool +calc_dominance_cb(nir_block *block, void *_state) +{ + dom_state *state = (dom_state *) _state; + if (block == state->impl->start_block) + return true; + + nir_block *new_idom = NULL; + struct set_entry *entry; + set_foreach(block->predecessors, entry) { + nir_block *pred = (nir_block *) entry->key; + + if (pred->imm_dom) { + if (new_idom) + new_idom = intersect(pred, new_idom); + else + new_idom = pred; + } + } + + assert(new_idom); + if (block->imm_dom != new_idom) { + block->imm_dom = new_idom; + state->progress = true; + } + + return true; +} + +static bool +calc_dom_frontier_cb(nir_block *block, void *state) +{ + (void) state; + + if (block->predecessors->entries > 1) { + struct set_entry *entry; + set_foreach(block->predecessors, entry) { + nir_block *runner = (nir_block *) entry->key; + while (runner != block->imm_dom) { + _mesa_set_add(runner->dom_frontier, _mesa_hash_pointer(block), + block); + runner = runner->imm_dom; + } + } + } + + return true; +} + +/* + * Compute each node's children in the dominance tree from the immediate + * dominator information. We do this in three stages: + * + * 1. Calculate the number of children each node has + * 2. Allocate arrays, setting the number of children to 0 again + * 3. For each node, add itself to its parent's list of children, using + * num_dom_children as an index - at the end of this step, num_dom_children + * for each node will be the same as it was at the end of step #1. + */ + +static bool +block_count_children(nir_block *block, void *state) +{ + (void) state; + + if (block->imm_dom) + block->imm_dom->num_dom_children++; + + return true; +} + +static bool +block_alloc_children(nir_block *block, void *state) +{ + void *mem_ctx = state; + + block->dom_children = ralloc_array(mem_ctx, nir_block *, + block->num_dom_children); + block->num_dom_children = 0; + + return true; +} + +static bool +block_add_child(nir_block *block, void *state) +{ + (void) state; + + if (block->imm_dom) + block->imm_dom->dom_children[block->imm_dom->num_dom_children++] = block; + + return true; +} + +static void +calc_dom_children(nir_function_impl* impl) +{ + void *mem_ctx = ralloc_parent(impl); + + nir_foreach_block(impl, block_count_children, NULL); + nir_foreach_block(impl, block_alloc_children, mem_ctx); + nir_foreach_block(impl, block_add_child, NULL); +} + +void +nir_calc_dominance_impl(nir_function_impl *impl) +{ + if (!impl->dominance_dirty) + return; + + nir_index_blocks(impl); + + dom_state state; + state.impl = impl; + state.progress = true; + + nir_foreach_block(impl, init_block_cb, &state); + + while (state.progress) { + state.progress = false; + nir_foreach_block(impl, calc_dominance_cb, &state); + } + + nir_foreach_block(impl, calc_dom_frontier_cb, &state); + + impl->start_block->imm_dom = NULL; + + calc_dom_children(impl); + + impl->dominance_dirty = false; +} + +void +nir_calc_dominance(nir_shader *shader) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_calc_dominance_impl(overload->impl); + } +} + +static bool +dump_block_dom(nir_block *block, void *state) +{ + FILE *fp = (FILE *) state; + if (block->imm_dom) + fprintf(fp, "\t%u -> %u\n", block->imm_dom->index, block->index); + return true; +} + +void +nir_dump_dom_tree_impl(nir_function_impl *impl, FILE *fp) +{ + fprintf(fp, "digraph doms_%s {\n", impl->overload->function->name); + nir_foreach_block(impl, dump_block_dom, fp); + fprintf(fp, "}\n\n"); +} + +void +nir_dump_dom_tree(nir_shader *shader, FILE *fp) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_dump_dom_tree_impl(overload->impl, fp); + } +} + +static bool +dump_block_dom_frontier(nir_block *block, void *state) +{ + FILE *fp = (FILE *) state; + + fprintf(fp, "DF(%u) = {", block->index); + struct set_entry *entry; + set_foreach(block->dom_frontier, entry) { + nir_block *df = (nir_block *) entry->key; + fprintf(fp, "%u, ", df->index); + } + fprintf(fp, "}\n"); + return true; +} + +void +nir_dump_dom_frontier_impl(nir_function_impl *impl, FILE *fp) +{ + nir_foreach_block(impl, dump_block_dom_frontier, fp); +} + +void +nir_dump_dom_frontier(nir_shader *shader, FILE *fp) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_dump_dom_frontier_impl(overload->impl, fp); + } +} + +static bool +dump_block_succs(nir_block *block, void *state) +{ + FILE *fp = (FILE *) state; + if (block->successors[0]) + fprintf(fp, "\t%u -> %u\n", block->index, block->successors[0]->index); + if (block->successors[1]) + fprintf(fp, "\t%u -> %u\n", block->index, block->successors[1]->index); + return true; +} + +void +nir_dump_cfg_impl(nir_function_impl *impl, FILE *fp) +{ + fprintf(fp, "digraph cfg_%s {\n", impl->overload->function->name); + nir_foreach_block(impl, dump_block_succs, fp); + fprintf(fp, "}\n\n"); +} + +void +nir_dump_cfg(nir_shader *shader, FILE *fp) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_dump_cfg_impl(overload->impl, fp); + } +} |