aco_form_hard_clauses.cpp

/*
 * Copyright © 2020 Valve Corporation
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 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
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 * The above copyright notice and this permission notice (including the next
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
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#include "aco_builder.h"
#include "aco_ir.h"

#include <vector>

namespace aco {
namespace {

/* there can also be LDS and VALU clauses, but I don't see how those are interesting */
enum clause_type {
   clause_vmem,
   clause_flat,
   clause_smem,
   clause_other,
};

void
emit_clause(Builder& bld, unsigned num_instrs, aco_ptr<Instruction>* instrs)
{
   unsigned start = 0;

   /* skip any stores at the start */
   for (; (start < num_instrs) && instrs[start]->definitions.empty(); start++)
      bld.insert(std::move(instrs[start]));

   unsigned end = start;
   for (; (end < num_instrs) && !instrs[end]->definitions.empty(); end++)
      ;
   unsigned clause_size = end - start;

   if (clause_size > 1)
      bld.sopp(aco_opcode::s_clause, -1, clause_size - 1);

   for (unsigned i = start; i < num_instrs; i++)
      bld.insert(std::move(instrs[i]));
}

} /* end namespace */

void
form_hard_clauses(Program* program)
{
   for (Block& block : program->blocks) {
      unsigned num_instrs = 0;
      aco_ptr<Instruction> current_instrs[64];
      clause_type current_type = clause_other;

      std::vector<aco_ptr<Instruction>> new_instructions;
      new_instructions.reserve(block.instructions.size());
      Builder bld(program, &new_instructions);

      for (unsigned i = 0; i < block.instructions.size(); i++) {
         aco_ptr<Instruction>& instr = block.instructions[i];

         clause_type type = clause_other;
         if (instr->isVMEM() && !instr->operands.empty()) {
            if (program->chip_class == GFX10 && instr->isMIMG() &&
                get_mimg_nsa_dwords(instr.get()) > 0)
               type = clause_other;
            else
               type = clause_vmem;
         } else if (instr->isScratch() || instr->isGlobal()) {
            type = clause_vmem;
         } else if (instr->isFlat()) {
            type = clause_flat;
         } else if (instr->isSMEM() && !instr->operands.empty()) {
            type = clause_smem;
         }

         if (type != current_type || num_instrs == 64 ||
             (num_instrs && !should_form_clause(current_instrs[0].get(), instr.get()))) {
            emit_clause(bld, num_instrs, current_instrs);
            num_instrs = 0;
            current_type = type;
         }

         if (type == clause_other) {
            bld.insert(std::move(instr));
            continue;
         }

         current_instrs[num_instrs++] = std::move(instr);
      }

      emit_clause(bld, num_instrs, current_instrs);

      block.instructions = std::move(new_instructions);
   }
}
} // namespace aco