*
* Authors:
* Jason Ekstrand (jason@jlekstrand.net)
+ * Connor Abbott (cwabbott0@gmail.com)
*
*/
-#include "nir.h"
+#include "nir_instr_set.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;
-
- if (alu1->has_predicate != alu2->has_predicate)
- return false;
-
- if (alu1->has_predicate &&
- !nir_srcs_equal(alu1->predicate, alu2->predicate))
- 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->num_components != load2->num_components)
- return false;
-
- return memcmp(load1->value.f, load2->value.f,
- load1->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;
-
- foreach_list_typed(nir_phi_src, src1, node, &phi1->srcs) {
- foreach_list_typed(nir_phi_src, src2, node, &phi2->srcs) {
- if (src1->pred == src2->pred) {
- if (!nir_srcs_equal(src1->src, src2->src))
- return false;
-
- break;
- }
- }
- }
-
- return true;
- }
- case nir_instr_type_intrinsic:
- 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;
-}
+/*
+ * Visits and CSE's the given block and all its descendants in the dominance
+ * tree recursively. Note that the instr_set is guaranteed to only ever
+ * contain instructions that dominate the current block.
+ */
static bool
-nir_instr_can_cse(nir_instr *instr)
-{
- switch (instr->type) {
- case nir_instr_type_alu:
- case nir_instr_type_load_const:
- case nir_instr_type_phi:
- return nir_foreach_dest(instr, dest_is_ssa, NULL) &&
- nir_foreach_src(instr, src_is_ssa, NULL);
- case nir_instr_type_tex:
- return false; /* TODO */
- case nir_instr_type_intrinsic:
- 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:
- assert(nir_instr_as_load_const(instr)->dest.is_ssa);
- return &nir_instr_as_load_const(instr)->dest.ssa;
- case nir_instr_type_phi:
- assert(nir_instr_as_phi(instr)->dest.is_ssa);
- return &nir_instr_as_phi(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)
+cse_block(nir_block *block, struct set *instr_set)
{
- if (!nir_instr_can_cse(instr))
- return;
+ bool progress = false;
- 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_src other_dest_src = {
- .is_ssa = true,
- .ssa = nir_instr_get_dest_ssa_def(other),
- };
- nir_ssa_def_rewrite_uses(nir_instr_get_dest_ssa_def(instr),
- other_dest_src, state->mem_ctx);
+ nir_foreach_instr_safe(block, instr) {
+ if (nir_instr_set_add_or_rewrite(instr_set, instr)) {
+ progress = true;
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_src other_dest_src = {
- .is_ssa = true,
- .ssa = nir_instr_get_dest_ssa_def(other),
- };
- nir_ssa_def_rewrite_uses(nir_instr_get_dest_ssa_def(instr),
- other_dest_src, state->mem_ctx);
- nir_instr_remove(instr);
- state->progress = true;
- return;
- }
- }
+ for (unsigned i = 0; i < block->num_dom_children; i++) {
+ nir_block *child = block->dom_children[i];
+ progress |= cse_block(child, instr_set);
}
-}
-static bool
-nir_opt_cse_block(nir_block *block, void *void_state)
-{
- struct cse_state *state = void_state;
+ nir_foreach_instr(block, instr)
+ nir_instr_set_remove(instr_set, instr);
- nir_foreach_instr_safe(block, instr)
- nir_opt_cse_instr(instr, state);
-
- return true;
+ return progress;
}
static bool
nir_opt_cse_impl(nir_function_impl *impl)
{
- struct cse_state state;
-
- state.mem_ctx = ralloc_parent(impl);
- state.progress = false;
+ struct set *instr_set = nir_instr_set_create(NULL);
nir_metadata_require(impl, nir_metadata_dominance);
- nir_foreach_block(impl, nir_opt_cse_block, &state);
+ bool progress = cse_block(nir_start_block(impl), instr_set);
- if (state.progress)
+ if (progress)
nir_metadata_preserve(impl, nir_metadata_block_index |
nir_metadata_dominance);
- return state.progress;
+ nir_instr_set_destroy(instr_set);
+ return progress;
}
bool
return progress;
}
+
projects / mesa.git / blobdiff