diff options
Diffstat (limited to 'src/compiler')
| -rw-r--r-- | src/compiler/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/compiler/nir/Makefile.sources | 1 | ||||
| -rw-r--r-- | src/compiler/nir/nir.h | 3 | ||||
| -rw-r--r-- | src/compiler/nir/nir_repair_ssa.c | 158 |
4 files changed, 163 insertions, 0 deletions
diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources index c38454e0267..796d0044f46 100644 --- a/src/compiler/Makefile.sources +++ b/src/compiler/Makefile.sources @@ -218,6 +218,7 @@ NIR_FILES = \ nir/nir_phi_builder.c \ nir/nir_phi_builder.h \ nir/nir_print.c \ + nir/nir_repair_ssa.c \ nir/nir_remove_dead_variables.c \ nir/nir_search.c \ nir/nir_search.h \ diff --git a/src/compiler/nir/Makefile.sources b/src/compiler/nir/Makefile.sources index db3eeccf858..c1493551192 100644 --- a/src/compiler/nir/Makefile.sources +++ b/src/compiler/nir/Makefile.sources @@ -61,6 +61,7 @@ NIR_FILES = \ nir_phi_builder.c \ nir_phi_builder.h \ nir_print.c \ + nir_repair_ssa.c \ nir_remove_dead_variables.c \ nir_search.c \ nir_search.h \ diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 76a511c2d4f..a4596096b59 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -2235,6 +2235,9 @@ bool nir_ssa_defs_interfere(nir_ssa_def *a, nir_ssa_def *b); void nir_convert_to_ssa_impl(nir_function_impl *impl); void nir_convert_to_ssa(nir_shader *shader); +bool nir_repair_ssa_impl(nir_function_impl *impl); +bool nir_repair_ssa(nir_shader *shader); + /* If phi_webs_only is true, only convert SSA values involved in phi nodes to * registers. If false, convert all values (even those not involved in a phi * node) to registers. diff --git a/src/compiler/nir/nir_repair_ssa.c b/src/compiler/nir/nir_repair_ssa.c new file mode 100644 index 00000000000..96c791cbc6b --- /dev/null +++ b/src/compiler/nir/nir_repair_ssa.c @@ -0,0 +1,158 @@ +/* + * Copyright © 2016 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. + */ + +#include "nir.h" +#include "nir_phi_builder.h" + +struct repair_ssa_state { + nir_function_impl *impl; + + BITSET_WORD *def_set; + struct nir_phi_builder *phi_builder; + + bool progress; +}; + +/* Get ready to build a phi and return the builder */ +static struct nir_phi_builder * +prep_build_phi(struct repair_ssa_state *state) +{ + const unsigned num_words = BITSET_WORDS(state->impl->num_blocks); + + /* We create the phi builder on-demand. */ + if (state->phi_builder == NULL) { + state->phi_builder = nir_phi_builder_create(state->impl); + state->def_set = ralloc_array(NULL, BITSET_WORD, num_words); + } + + /* We're going to build a phi. That's progress. */ + state->progress = true; + + /* Set the defs set to empty */ + memset(state->def_set, 0, num_words * sizeof(*state->def_set)); + + return state->phi_builder; +} + +static nir_block * +get_src_block(nir_src *src) +{ + if (src->parent_instr->type == nir_instr_type_phi) { + return exec_node_data(nir_phi_src, src, src)->pred; + } else { + return src->parent_instr->block; + } +} + +static bool +repair_ssa_def(nir_ssa_def *def, void *void_state) +{ + struct repair_ssa_state *state = void_state; + + bool is_valid = true; + nir_foreach_use(def, src) { + if (!nir_block_dominates(def->parent_instr->block, get_src_block(src))) { + is_valid = false; + break; + } + } + + if (is_valid) + return true; + + struct nir_phi_builder *pb = prep_build_phi(state); + + BITSET_SET(state->def_set, def->parent_instr->block->index); + + struct nir_phi_builder_value *val = + nir_phi_builder_add_value(pb, def->num_components, def->bit_size, + state->def_set); + + nir_phi_builder_value_set_block_def(val, def->parent_instr->block, def); + + nir_foreach_use_safe(def, src) { + nir_block *src_block = get_src_block(src); + if (!nir_block_dominates(def->parent_instr->block, src_block)) { + nir_instr_rewrite_src(src->parent_instr, src, nir_src_for_ssa( + nir_phi_builder_value_get_block_def(val, src_block))); + } + } + + return true; +} + +static bool +repair_ssa_block(nir_block *block, void *state) +{ + nir_foreach_instr_safe(block, instr) { + nir_foreach_ssa_def(instr, repair_ssa_def, state); + } + + return true; +} + +bool +nir_repair_ssa_impl(nir_function_impl *impl) +{ + struct repair_ssa_state state; + + state.impl = impl; + state.phi_builder = NULL; + state.progress = false; + + nir_metadata_require(impl, nir_metadata_block_index | + nir_metadata_dominance); + + nir_foreach_block(impl, repair_ssa_block, &state); + + if (state.progress) + nir_metadata_preserve(impl, nir_metadata_block_index | + nir_metadata_dominance); + + if (state.phi_builder) { + nir_phi_builder_finish(state.phi_builder); + ralloc_free(state.def_set); + } + + return state.progress; +} + +/** This pass can be used to repair SSA form in a shader. + * + * Sometimes a transformation (such as return lowering) will have to make + * changes to a shader which, while still correct, break some of NIR's SSA + * invariants. This pass will insert ssa_undefs and phi nodes as needed to + * get the shader back into SSA that the validator will like. + */ +bool +nir_repair_ssa(nir_shader *shader) +{ + bool progress = false; + + nir_foreach_function(shader, function) { + if (function->impl) + progress = nir_repair_ssa_impl(function->impl) || progress; + } + + return progress; +} |