Function GetInsertedValues

source/opt/folding_rules.cpp:2707–2733

Returns a map with the set of values that were inserted into an object by the chain of OpCompositeInsertInstruction starting with |inst|. The map will map the index to the value inserted at that index. An empty map will be returned if the map could not be properly generated.

// The map will map the index to the value inserted at that index. An empty map
// will be returned if the map could not be properly generated.
std::map<uint32_t, uint32_t> GetInsertedValues(Instruction* inst) {
  analysis::DefUseManager* def_use_mgr = inst->context()->get_def_use_mgr();
  std::map<uint32_t, uint32_t> values_inserted;
  Instruction* current_inst = inst;
  while (current_inst->opcode() == spv::Op::OpCompositeInsert) {
    if (current_inst->NumInOperands() > inst->NumInOperands()) {
      // This is to catch the case
      //   %2 = OpCompositeInsert %m2x2int %v2int_1_0 %m2x2int_undef 0
      //   %3 = OpCompositeInsert %m2x2int %int_4 %2 0 0
      //   %4 = OpCompositeInsert %m2x2int %v2int_2_3 %3 1
      // In this case we cannot do a single construct to get the matrix.
      uint32_t partially_inserted_element_index =
          current_inst->GetSingleWordInOperand(inst->NumInOperands() - 1);
      if (values_inserted.count(partially_inserted_element_index) == 0)
        return {};
    }
    if (HaveSameIndexesExceptForLast(inst, current_inst)) {
      values_inserted.insert(
          {current_inst->GetSingleWordInOperand(current_inst->NumInOperands() -
                                                1),
           current_inst->GetSingleWordInOperand(kInsertObjectIdInIdx)});
    }
    current_inst = def_use_mgr->GetDef(
        current_inst->GetSingleWordInOperand(kInsertCompositeIdInIdx));
  }
  return values_inserted;
}

// Returns true of there is an entry in |values_inserted| for every element of
// |Type|.