| /* |
| * 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" |
| |
| static void |
| add_src(nir_src *src, struct set *invariants) |
| { |
| if (src->is_ssa) { |
| _mesa_set_add(invariants, src->ssa); |
| } else { |
| _mesa_set_add(invariants, src->reg.reg); |
| } |
| } |
| |
| static bool |
| add_src_cb(nir_src *src, void *state) |
| { |
| add_src(src, state); |
| return true; |
| } |
| |
| static bool |
| dest_is_invariant(nir_dest *dest, struct set *invariants) |
| { |
| if (dest->is_ssa) { |
| return _mesa_set_search(invariants, &dest->ssa); |
| } else { |
| return _mesa_set_search(invariants, dest->reg.reg); |
| } |
| } |
| |
| static void |
| add_cf_node(nir_cf_node *cf, struct set *invariants) |
| { |
| if (cf->type == nir_cf_node_if) { |
| nir_if *if_stmt = nir_cf_node_as_if(cf); |
| add_src(&if_stmt->condition, invariants); |
| } |
| |
| if (cf->parent) |
| add_cf_node(cf->parent, invariants); |
| } |
| |
| static void |
| add_var(nir_variable *var, struct set *invariants) |
| { |
| /* Because we pass the result of nir_intrinsic_get_var directly to this |
| * function, it's possible for var to be NULL if, for instance, there's a |
| * cast somewhere in the chain. |
| */ |
| if (var != NULL) |
| _mesa_set_add(invariants, var); |
| } |
| |
| static bool |
| var_is_invariant(nir_variable *var, struct set * invariants) |
| { |
| /* Because we pass the result of nir_intrinsic_get_var directly to this |
| * function, it's possible for var to be NULL if, for instance, there's a |
| * cast somewhere in the chain. |
| */ |
| return var && (var->data.invariant || _mesa_set_search(invariants, var)); |
| } |
| |
| static void |
| propagate_invariant_instr(nir_instr *instr, struct set *invariants) |
| { |
| switch (instr->type) { |
| case nir_instr_type_alu: { |
| nir_alu_instr *alu = nir_instr_as_alu(instr); |
| if (!dest_is_invariant(&alu->dest.dest, invariants)) |
| break; |
| |
| alu->exact = true; |
| nir_foreach_src(instr, add_src_cb, invariants); |
| break; |
| } |
| |
| case nir_instr_type_tex: { |
| nir_tex_instr *tex = nir_instr_as_tex(instr); |
| if (dest_is_invariant(&tex->dest, invariants)) |
| nir_foreach_src(instr, add_src_cb, invariants); |
| break; |
| } |
| |
| case nir_instr_type_intrinsic: { |
| nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); |
| switch (intrin->intrinsic) { |
| case nir_intrinsic_copy_deref: |
| /* If the destination is invariant then so is the source */ |
| if (var_is_invariant(nir_intrinsic_get_var(intrin, 0), invariants)) |
| add_var(nir_intrinsic_get_var(intrin, 1), invariants); |
| break; |
| |
| case nir_intrinsic_load_deref: |
| if (dest_is_invariant(&intrin->dest, invariants)) |
| add_var(nir_intrinsic_get_var(intrin, 0), invariants); |
| break; |
| |
| case nir_intrinsic_store_deref: |
| if (var_is_invariant(nir_intrinsic_get_var(intrin, 0), invariants)) |
| add_src(&intrin->src[1], invariants); |
| break; |
| |
| default: |
| /* Nothing to do */ |
| break; |
| } |
| } |
| |
| case nir_instr_type_deref: |
| case nir_instr_type_jump: |
| case nir_instr_type_ssa_undef: |
| case nir_instr_type_load_const: |
| break; /* Nothing to do */ |
| |
| case nir_instr_type_phi: { |
| nir_phi_instr *phi = nir_instr_as_phi(instr); |
| if (!dest_is_invariant(&phi->dest, invariants)) |
| break; |
| |
| nir_foreach_phi_src(src, phi) { |
| add_src(&src->src, invariants); |
| add_cf_node(&src->pred->cf_node, invariants); |
| } |
| break; |
| } |
| |
| case nir_instr_type_call: |
| unreachable("This pass must be run after function inlining"); |
| |
| case nir_instr_type_parallel_copy: |
| default: |
| unreachable("Cannot have this instruction type"); |
| } |
| } |
| |
| static bool |
| propagate_invariant_impl(nir_function_impl *impl, struct set *invariants) |
| { |
| bool progress = false; |
| |
| while (true) { |
| uint32_t prev_entries = invariants->entries; |
| |
| nir_foreach_block_reverse(block, impl) { |
| nir_foreach_instr_reverse(instr, block) |
| propagate_invariant_instr(instr, invariants); |
| } |
| |
| /* Keep running until we make no more progress. */ |
| if (invariants->entries > prev_entries) { |
| progress = true; |
| continue; |
| } else { |
| break; |
| } |
| } |
| |
| if (progress) { |
| nir_metadata_preserve(impl, nir_metadata_block_index | |
| nir_metadata_dominance | |
| nir_metadata_live_ssa_defs); |
| } |
| |
| return progress; |
| } |
| |
| bool |
| nir_propagate_invariant(nir_shader *shader) |
| { |
| /* Hash set of invariant things */ |
| struct set *invariants = _mesa_pointer_set_create(NULL); |
| |
| bool progress = false; |
| nir_foreach_function(function, shader) { |
| if (function->impl && propagate_invariant_impl(function->impl, invariants)) |
| progress = true; |
| } |
| |
| _mesa_set_destroy(invariants, NULL); |
| |
| return progress; |
| } |