Function RedundantSUMod

source/opt/folding_rules.cpp:3839–3857

This rule handles modulo from division by 1 or vector 1 (a % 1 => 0).

// This rule handles modulo from division by 1 or vector 1 (a % 1 => 0).
FoldingRule RedundantSUMod() {
  return [](IRContext* context, Instruction* inst,
            const std::vector<const analysis::Constant*>& constants) {
    assert(constants.size() == 2);
    assert((inst->opcode() == spv::Op::OpUMod ||
            inst->opcode() == spv::Op::OpSMod) &&
           "Wrong opcode.");

    if (constants[1] && IsAllInt1(constants[1])) {
      auto type = context->get_type_mgr()->GetType(inst->type_id());
      auto zero_id = context->get_constant_mgr()->GetNullConstId(type);

      inst->SetOpcode(spv::Op::OpCopyObject);
      inst->SetInOperands({{SPV_OPERAND_TYPE_ID, {zero_id}}});
      return true;
    }
    return false;
  };
}

// Utility function for applying |callback| to |input1| and |input2|.
// If they are vectors it applies element wise.