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-rw-r--r--src/compiler/nir/nir_opt_copy_propagate.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_opt_copy_propagate.c b/src/compiler/nir/nir_opt_copy_propagate.c
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+++ b/src/compiler/nir/nir_opt_copy_propagate.c
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+/*
+ * 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"
+#include <main/imports.h>
+
+/**
+ * SSA-based copy propagation
+ */
+
+static bool is_move(nir_alu_instr *instr)
+{
+ if (instr->op != nir_op_fmov &&
+ instr->op != nir_op_imov)
+ return false;
+
+ if (instr->dest.saturate)
+ return false;
+
+ /* we handle modifiers in a separate pass */
+
+ if (instr->src[0].abs || instr->src[0].negate)
+ return false;
+
+ if (!instr->src[0].src.is_ssa)
+ return false;
+
+ return true;
+
+}
+
+static bool is_vec(nir_alu_instr *instr)
+{
+ for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
+ if (!instr->src[i].src.is_ssa)
+ return false;
+
+ /* we handle modifiers in a separate pass */
+ if (instr->src[i].abs || instr->src[i].negate)
+ return false;
+ }
+
+ return instr->op == nir_op_vec2 ||
+ instr->op == nir_op_vec3 ||
+ instr->op == nir_op_vec4;
+}
+
+static bool
+is_swizzleless_move(nir_alu_instr *instr)
+{
+ if (is_move(instr)) {
+ for (unsigned i = 0; i < 4; i++) {
+ if (!((instr->dest.write_mask >> i) & 1))
+ break;
+ if (instr->src[0].swizzle[i] != i)
+ return false;
+ }
+ return true;
+ } else if (is_vec(instr)) {
+ nir_ssa_def *def = NULL;
+ for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
+ if (instr->src[i].swizzle[0] != i)
+ return false;
+
+ if (def == NULL) {
+ def = instr->src[i].src.ssa;
+ } else if (instr->src[i].src.ssa != def) {
+ return false;
+ }
+ }
+ return true;
+ } else {
+ return false;
+ }
+}
+
+static bool
+copy_prop_src(nir_src *src, nir_instr *parent_instr, nir_if *parent_if)
+{
+ if (!src->is_ssa) {
+ if (src->reg.indirect)
+ return copy_prop_src(src, parent_instr, parent_if);
+ return false;
+ }
+
+ nir_instr *src_instr = src->ssa->parent_instr;
+ if (src_instr->type != nir_instr_type_alu)
+ return false;
+
+ nir_alu_instr *alu_instr = nir_instr_as_alu(src_instr);
+ if (!is_swizzleless_move(alu_instr))
+ return false;
+
+ /* Don't let copy propagation land us with a phi that has more
+ * components in its source than it has in its destination. That badly
+ * messes up out-of-ssa.
+ */
+ if (parent_instr && parent_instr->type == nir_instr_type_phi) {
+ nir_phi_instr *phi = nir_instr_as_phi(parent_instr);
+ assert(phi->dest.is_ssa);
+ if (phi->dest.ssa.num_components !=
+ alu_instr->src[0].src.ssa->num_components)
+ return false;
+ }
+
+ if (parent_instr) {
+ nir_instr_rewrite_src(parent_instr, src,
+ nir_src_for_ssa(alu_instr->src[0].src.ssa));
+ } else {
+ assert(src == &parent_if->condition);
+ nir_if_rewrite_condition(parent_if,
+ nir_src_for_ssa(alu_instr->src[0].src.ssa));
+ }
+
+ return true;
+}
+
+static bool
+copy_prop_alu_src(nir_alu_instr *parent_alu_instr, unsigned index)
+{
+ nir_alu_src *src = &parent_alu_instr->src[index];
+ if (!src->src.is_ssa) {
+ if (src->src.reg.indirect)
+ return copy_prop_src(src->src.reg.indirect, &parent_alu_instr->instr,
+ NULL);
+ return false;
+ }
+
+ nir_instr *src_instr = src->src.ssa->parent_instr;
+ if (src_instr->type != nir_instr_type_alu)
+ return false;
+
+ nir_alu_instr *alu_instr = nir_instr_as_alu(src_instr);
+ if (!is_move(alu_instr) && !is_vec(alu_instr))
+ return false;
+
+ nir_ssa_def *def;
+ unsigned new_swizzle[4] = {0, 0, 0, 0};
+
+ if (alu_instr->op == nir_op_fmov ||
+ alu_instr->op == nir_op_imov) {
+ for (unsigned i = 0; i < 4; i++)
+ new_swizzle[i] = alu_instr->src[0].swizzle[src->swizzle[i]];
+ def = alu_instr->src[0].src.ssa;
+ } else {
+ def = NULL;
+
+ for (unsigned i = 0; i < 4; i++) {
+ if (!nir_alu_instr_channel_used(parent_alu_instr, index, i))
+ continue;
+
+ nir_ssa_def *new_def = alu_instr->src[src->swizzle[i]].src.ssa;
+ if (def == NULL)
+ def = new_def;
+ else {
+ if (def != new_def)
+ return false;
+ }
+ new_swizzle[i] = alu_instr->src[src->swizzle[i]].swizzle[0];
+ }
+ }
+
+ for (unsigned i = 0; i < 4; i++)
+ src->swizzle[i] = new_swizzle[i];
+
+ nir_instr_rewrite_src(&parent_alu_instr->instr, &src->src,
+ nir_src_for_ssa(def));
+
+ return true;
+}
+
+typedef struct {
+ nir_instr *parent_instr;
+ bool progress;
+} copy_prop_state;
+
+static bool
+copy_prop_src_cb(nir_src *src, void *_state)
+{
+ copy_prop_state *state = (copy_prop_state *) _state;
+ while (copy_prop_src(src, state->parent_instr, NULL))
+ state->progress = true;
+
+ return true;
+}
+
+static bool
+copy_prop_instr(nir_instr *instr)
+{
+ if (instr->type == nir_instr_type_alu) {
+ nir_alu_instr *alu_instr = nir_instr_as_alu(instr);
+ bool progress = false;
+
+ for (unsigned i = 0; i < nir_op_infos[alu_instr->op].num_inputs; i++)
+ while (copy_prop_alu_src(alu_instr, i))
+ progress = true;
+
+ if (!alu_instr->dest.dest.is_ssa && alu_instr->dest.dest.reg.indirect)
+ while (copy_prop_src(alu_instr->dest.dest.reg.indirect, instr, NULL))
+ progress = true;
+
+ return progress;
+ }
+
+ copy_prop_state state;
+ state.parent_instr = instr;
+ state.progress = false;
+ nir_foreach_src(instr, copy_prop_src_cb, &state);
+
+ return state.progress;
+}
+
+static bool
+copy_prop_if(nir_if *if_stmt)
+{
+ return copy_prop_src(&if_stmt->condition, NULL, if_stmt);
+}
+
+static bool
+copy_prop_block(nir_block *block, void *_state)
+{
+ bool *progress = (bool *) _state;
+
+ nir_foreach_instr(block, instr) {
+ if (copy_prop_instr(instr))
+ *progress = true;
+ }
+
+ if (block->cf_node.node.next != NULL && /* check that we aren't the end node */
+ !nir_cf_node_is_last(&block->cf_node) &&
+ nir_cf_node_next(&block->cf_node)->type == nir_cf_node_if) {
+ nir_if *if_stmt = nir_cf_node_as_if(nir_cf_node_next(&block->cf_node));
+ if (copy_prop_if(if_stmt))
+ *progress = true;
+ }
+
+ return true;
+}
+
+static bool
+nir_copy_prop_impl(nir_function_impl *impl)
+{
+ bool progress = false;
+
+ nir_foreach_block(impl, copy_prop_block, &progress);
+
+ if (progress) {
+ nir_metadata_preserve(impl, nir_metadata_block_index |
+ nir_metadata_dominance);
+ }
+
+ return progress;
+}
+
+bool
+nir_copy_prop(nir_shader *shader)
+{
+ bool progress = false;
+
+ nir_foreach_function(shader, function) {
+ if (function->impl && nir_copy_prop_impl(function->impl))
+ progress = true;
+ }
+
+ return progress;
+}
generated by cgit v1.1 at 2024-05-28 20:15:29 +0000