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Diffstat (limited to 'mesalib/src/glsl/nir/nir_opt_cse.c')
-rw-r--r--mesalib/src/glsl/nir/nir_opt_cse.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/mesalib/src/glsl/nir/nir_opt_cse.c b/mesalib/src/glsl/nir/nir_opt_cse.c
new file mode 100644
index 000000000..9b383202d
--- /dev/null
+++ b/mesalib/src/glsl/nir/nir_opt_cse.c
@@ -0,0 +1,297 @@
+/*
+ * 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:
+ * Jason Ekstrand (jason@jlekstrand.net)
+ *
+ */
+
+#include "nir.h"
+
+/*
+ * Implements common subexpression elimination
+ */
+
+struct cse_state {
+ void *mem_ctx;
+ bool progress;
+};
+
+static bool
+nir_alu_srcs_equal(nir_alu_src src1, nir_alu_src src2, uint8_t read_mask)
+{
+ if (src1.abs != src2.abs || src1.negate != src2.negate)
+ return false;
+
+ for (int i = 0; i < 4; ++i) {
+ if (!(read_mask & (1 << i)))
+ continue;
+
+ if (src1.swizzle[i] != src2.swizzle[i])
+ return false;
+ }
+
+ return nir_srcs_equal(src1.src, src2.src);
+}
+
+static bool
+nir_instrs_equal(nir_instr *instr1, nir_instr *instr2)
+{
+ if (instr1->type != instr2->type)
+ return false;
+
+ switch (instr1->type) {
+ case nir_instr_type_alu: {
+ nir_alu_instr *alu1 = nir_instr_as_alu(instr1);
+ nir_alu_instr *alu2 = nir_instr_as_alu(instr2);
+
+ if (alu1->op != alu2->op)
+ return false;
+
+ /* TODO: We can probably acutally do something more inteligent such
+ * as allowing different numbers and taking a maximum or something
+ * here */
+ if (alu1->dest.dest.ssa.num_components != alu2->dest.dest.ssa.num_components)
+ return false;
+
+ for (unsigned i = 0; i < nir_op_infos[alu1->op].num_inputs; i++) {
+ if (!nir_alu_srcs_equal(alu1->src[i], alu2->src[i],
+ (1 << alu1->dest.dest.ssa.num_components) - 1))
+ return false;
+ }
+ return true;
+ }
+ case nir_instr_type_tex:
+ return false;
+ case nir_instr_type_load_const: {
+ nir_load_const_instr *load1 = nir_instr_as_load_const(instr1);
+ nir_load_const_instr *load2 = nir_instr_as_load_const(instr2);
+
+ if (load1->def.num_components != load2->def.num_components)
+ return false;
+
+ return memcmp(load1->value.f, load2->value.f,
+ load1->def.num_components * sizeof(*load2->value.f)) == 0;
+ }
+ case nir_instr_type_phi: {
+ nir_phi_instr *phi1 = nir_instr_as_phi(instr1);
+ nir_phi_instr *phi2 = nir_instr_as_phi(instr2);
+
+ if (phi1->instr.block != phi2->instr.block)
+ return false;
+
+ nir_foreach_phi_src(phi1, src1) {
+ nir_foreach_phi_src(phi2, src2) {
+ if (src1->pred == src2->pred) {
+ if (!nir_srcs_equal(src1->src, src2->src))
+ return false;
+
+ break;
+ }
+ }
+ }
+
+ return true;
+ }
+ case nir_instr_type_intrinsic: {
+ nir_intrinsic_instr *intrinsic1 = nir_instr_as_intrinsic(instr1);
+ nir_intrinsic_instr *intrinsic2 = nir_instr_as_intrinsic(instr2);
+ const nir_intrinsic_info *info =
+ &nir_intrinsic_infos[intrinsic1->intrinsic];
+
+ if (intrinsic1->intrinsic != intrinsic2->intrinsic ||
+ intrinsic1->num_components != intrinsic2->num_components)
+ return false;
+
+ if (info->has_dest && intrinsic1->dest.ssa.num_components !=
+ intrinsic2->dest.ssa.num_components)
+ return false;
+
+ for (unsigned i = 0; i < info->num_srcs; i++) {
+ if (!nir_srcs_equal(intrinsic1->src[i], intrinsic2->src[i]))
+ return false;
+ }
+
+ assert(info->num_variables == 0);
+
+ for (unsigned i = 0; i < info->num_indices; i++) {
+ if (intrinsic1->const_index[i] != intrinsic2->const_index[i])
+ return false;
+ }
+
+ return true;
+ }
+ case nir_instr_type_call:
+ case nir_instr_type_jump:
+ case nir_instr_type_ssa_undef:
+ case nir_instr_type_parallel_copy:
+ default:
+ unreachable("Invalid instruction type");
+ }
+
+ return false;
+}
+
+static bool
+src_is_ssa(nir_src *src, void *data)
+{
+ return src->is_ssa;
+}
+
+static bool
+dest_is_ssa(nir_dest *dest, void *data)
+{
+ return dest->is_ssa;
+}
+
+static bool
+nir_instr_can_cse(nir_instr *instr)
+{
+ /* We only handle SSA. */
+ if (!nir_foreach_dest(instr, dest_is_ssa, NULL) ||
+ !nir_foreach_src(instr, src_is_ssa, NULL))
+ return false;
+
+ switch (instr->type) {
+ case nir_instr_type_alu:
+ case nir_instr_type_load_const:
+ case nir_instr_type_phi:
+ return true;
+ case nir_instr_type_tex:
+ return false; /* TODO */
+ case nir_instr_type_intrinsic: {
+ const nir_intrinsic_info *info =
+ &nir_intrinsic_infos[nir_instr_as_intrinsic(instr)->intrinsic];
+ return (info->flags & NIR_INTRINSIC_CAN_ELIMINATE) &&
+ (info->flags & NIR_INTRINSIC_CAN_REORDER) &&
+ info->num_variables == 0; /* not implemented yet */
+ }
+ case nir_instr_type_call:
+ case nir_instr_type_jump:
+ case nir_instr_type_ssa_undef:
+ return false;
+ case nir_instr_type_parallel_copy:
+ default:
+ unreachable("Invalid instruction type");
+ }
+
+ return false;
+}
+
+static nir_ssa_def *
+nir_instr_get_dest_ssa_def(nir_instr *instr)
+{
+ switch (instr->type) {
+ case nir_instr_type_alu:
+ assert(nir_instr_as_alu(instr)->dest.dest.is_ssa);
+ return &nir_instr_as_alu(instr)->dest.dest.ssa;
+ case nir_instr_type_load_const:
+ return &nir_instr_as_load_const(instr)->def;
+ case nir_instr_type_phi:
+ assert(nir_instr_as_phi(instr)->dest.is_ssa);
+ return &nir_instr_as_phi(instr)->dest.ssa;
+ case nir_instr_type_intrinsic:
+ assert(nir_instr_as_intrinsic(instr)->dest.is_ssa);
+ return &nir_instr_as_intrinsic(instr)->dest.ssa;
+ default:
+ unreachable("We never ask for any of these");
+ }
+}
+
+static void
+nir_opt_cse_instr(nir_instr *instr, struct cse_state *state)
+{
+ if (!nir_instr_can_cse(instr))
+ return;
+
+ for (struct exec_node *node = instr->node.prev;
+ !exec_node_is_head_sentinel(node); node = node->prev) {
+ nir_instr *other = exec_node_data(nir_instr, node, node);
+ if (nir_instrs_equal(instr, other)) {
+ nir_ssa_def *other_def = nir_instr_get_dest_ssa_def(other);
+ nir_ssa_def_rewrite_uses(nir_instr_get_dest_ssa_def(instr),
+ nir_src_for_ssa(other_def),
+ state->mem_ctx);
+ nir_instr_remove(instr);
+ state->progress = true;
+ return;
+ }
+ }
+
+ for (nir_block *block = instr->block->imm_dom;
+ block != NULL; block = block->imm_dom) {
+ nir_foreach_instr_reverse(block, other) {
+ if (nir_instrs_equal(instr, other)) {
+ nir_ssa_def *other_def = nir_instr_get_dest_ssa_def(other);
+ nir_ssa_def_rewrite_uses(nir_instr_get_dest_ssa_def(instr),
+ nir_src_for_ssa(other_def),
+ state->mem_ctx);
+ nir_instr_remove(instr);
+ state->progress = true;
+ return;
+ }
+ }
+ }
+}
+
+static bool
+nir_opt_cse_block(nir_block *block, void *void_state)
+{
+ struct cse_state *state = void_state;
+
+ nir_foreach_instr_safe(block, instr)
+ nir_opt_cse_instr(instr, state);
+
+ return true;
+}
+
+static bool
+nir_opt_cse_impl(nir_function_impl *impl)
+{
+ struct cse_state state;
+
+ state.mem_ctx = ralloc_parent(impl);
+ state.progress = false;
+
+ nir_metadata_require(impl, nir_metadata_dominance);
+
+ nir_foreach_block(impl, nir_opt_cse_block, &state);
+
+ if (state.progress)
+ nir_metadata_preserve(impl, nir_metadata_block_index |
+ nir_metadata_dominance);
+
+ return state.progress;
+}
+
+bool
+nir_opt_cse(nir_shader *shader)
+{
+ bool progress = false;
+
+ nir_foreach_overload(shader, overload) {
+ if (overload->impl)
+ progress |= nir_opt_cse_impl(overload->impl);
+ }
+
+ return progress;
+}
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