From 202751fbb7e3d35c1aa84f325f862245dab67f6c Mon Sep 17 00:00:00 2001 From: Jason Ekstrand Date: Mon, 13 Jun 2016 12:47:19 -0700 Subject: [PATCH] nir: Add a pass for propagating invariant decorations This pass is similar to propagate_invariance in the GLSL compiler. The real "output" of this pass is that any algebraic operations which are eventually consumed by an invariant variable get marked as "exact". Signed-off-by: Jason Ekstrand Reviewed-by: Kenneth Graunke Cc: "12.0" --- src/compiler/Makefile.sources | 1 + src/compiler/nir/nir.h | 2 + src/compiler/nir/nir_propagate_invariant.c | 196 +++++++++++++++++++++ 3 files changed, 199 insertions(+) create mode 100644 src/compiler/nir/nir_propagate_invariant.c diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources index 5c4ea65b5e9..0ff9b23e4c3 100644 --- a/src/compiler/Makefile.sources +++ b/src/compiler/Makefile.sources @@ -231,6 +231,7 @@ NIR_FILES = \ nir/nir_phi_builder.c \ nir/nir_phi_builder.h \ nir/nir_print.c \ + nir/nir_propagate_invariant.c \ nir/nir_remove_dead_variables.c \ nir/nir_repair_ssa.c \ nir/nir_search.c \ diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index ec7b0c7726d..1725ee3de0a 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -2290,6 +2290,8 @@ bool nir_lower_returns(nir_shader *shader); bool nir_inline_functions(nir_shader *shader); +bool nir_propagate_invariant(nir_shader *shader); + void nir_lower_var_copy_instr(nir_intrinsic_instr *copy, void *mem_ctx); void nir_lower_var_copies(nir_shader *shader); diff --git a/src/compiler/nir/nir_propagate_invariant.c b/src/compiler/nir/nir_propagate_invariant.c new file mode 100644 index 00000000000..7b5bd6cce6b --- /dev/null +++ b/src/compiler/nir/nir_propagate_invariant.c @@ -0,0 +1,196 @@ +/* + * 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) +{ + _mesa_set_add(invariants, var); +} + +static bool +var_is_invariant(nir_variable *var, struct set * invariants) +{ + return 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_var: + /* If the destination is invariant then so is the source */ + if (var_is_invariant(intrin->variables[0]->var, invariants)) + add_var(intrin->variables[1]->var, invariants); + break; + + case nir_intrinsic_load_var: + if (dest_is_invariant(&intrin->dest, invariants)) + add_var(intrin->variables[0]->var, invariants); + break; + + case nir_intrinsic_store_var: + if (var_is_invariant(intrin->variables[0]->var, invariants)) + add_src(&intrin->src[0], invariants); + break; + + default: + /* Nothing to do */ + break; + } + } + + 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_set_create(NULL, _mesa_hash_pointer, + _mesa_key_pointer_equal); + + 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; +} -- 2.30.2