JP2014211682A - Information processor and information processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information processor capable of reducing the required quantity of a storage device in on-line algorithm type merge sort processing.SOLUTION: An information processor for performing merge sorting to stream data by using an on-line type algorithm includes: a storage part for storing at least a first half portion of data consisting of a first half portion and a second half portion input as the stream data, and separately sorted in advance in accordance with a predetermined rule; and a sort processing part for performing merge sorting to the data of the second half portion and the first half portion, and outputting the data. The sort processing part is configured so as to be shared by a region in which the first half portion is stored and a region in which the second half portion is stored in the storage part.

Description

  The present invention relates to a technique for rearranging a plurality of data, and more particularly to a technique for sorting stream data using an online algorithm.

  In the case where the conventional merge sorter is implemented on the stream data by an online algorithm, the number of merge sort target data in each stage of the merge sorter, that is, 2 ^ (n-1) in the case of the nth stage. Two sets of storage devices corresponding to 2 ^ n pieces of data were required.

  An example of a conventional merge sort is disclosed in Non-Patent Document 1. With reference to FIG. 7, the procedure of the merge sort disclosed in Non-Patent Document 1 will be described. The merge sort is a first stage for comparing each piece of data, a second stage for temporarily storing the results of the first stage in two sets of two each, and merging while comparing the two sets, The second stage results are stored in two sets of four each, and the third stage is merged while comparing them.

“Merge Sort [Merge Sort]”, [online], [Search April 2, 2013], Internet <URL: http://www.codereading.com/algo_and_ds/algo/merge_sort.html>

  In particular, in the online implementation of merge sort that keeps sorting without stagnation for constantly arriving data, as described below, the increase in the number of stages is inevitable due to the increase in the number of stages. .

  The first stage requires a storage device for each piece of data to be compared, and has a function of outputting the result of comparison in order of the specified magnitude in time, and the second stage has each data to be compared. Two storage devices are required, and as a result of the comparison, a function is provided to output in order of the designated magnitude in time. In general, the n-th stage requires a storage device for each (2 ^ (n-1)) pieces of data to be compared. It was necessary to prepare. This is because it is not possible to determine in advance how much of the two data strings will remain in the middle of the data comparison at each stage. This is because two sets of (2 ^ (n-1)) comparison target data must be prepared in n stages. For the uninterrupted operation expected for online implementation, it is necessary to provide a storage device for these sums.

  In addition, there is a problem that the required amount of storage devices required as hardware increases as the data to be processed increases.

  The present invention has been made to solve the above-described problems of the technology, and an information processing apparatus and information processing capable of reducing a required amount of a storage device in an online algorithm type merge sort process. It aims to provide a method.

In order to achieve the above object, an information processing apparatus of the present invention is an information processing apparatus that merges and sorts stream data using an online algorithm,
A storage unit that stores at least the first half part of the data consisting of the first half part and the second half part, which is input as the stream data and sorted separately in advance according to a predetermined rule;
A sort processing unit that outputs a merge sort of the data of the latter half and the first half, and
In the storage unit, the sort processing unit is configured to be shared by the area for storing the first half part and the area for storing the second half part.

The information processing method of the present invention is an information processing method by an information processing apparatus that performs merge sort on stream data using an online algorithm,
Of the data consisting of the first half part and the second half part separately sorted in advance according to a predetermined rule, the data of the first half part input as the stream data is stored in the storage unit of the information processing apparatus,
Merge sort and output the latter half of the data input as the stream data and the first half of the data stored in the storage unit,
When performing the merge sort, in the storage unit, the area for storing the first half part and the area for storing the second half part are shared.

  According to the present invention, the required amount of storage devices can be reduced, and the increase in hardware with respect to the increase in processing targets can be mitigated.

It is a block diagram which shows the example of 1 structure of the information processing apparatus of 1st Embodiment. It is a figure which shows the structural example of the nth stage of the merge sorter of 1st Embodiment. It is a flowchart which shows the operation | movement procedure of the merge sort by the information processing apparatus of 1st Embodiment. It is a figure which shows an example of the time series of the data used as the nth step input. It is a figure which shows an example of the time series of the data used as the output of the nth stage. It is a block diagram which shows the example of 1 structure of the merge sorter of 2nd Embodiment. It is a figure for demonstrating the procedure of the conventional merge sort.

  An embodiment of an information processing apparatus and an information processing method of the present invention constituting an online algorithm type merge sorter will be described.

(First embodiment)
The configuration of the information processing apparatus according to this embodiment will be described. This embodiment is a case of an online algorithm type merge sorter having a merge sorter from the first stage to the n-th stage (n is an integer of 2 or more). FIG. 1 is a block diagram illustrating a configuration example of the information processing apparatus according to the present embodiment.

  As illustrated in FIG. 1, the information processing apparatus 10 includes an input unit 11 that receives stream data coming from a previous sorter, a storage unit 12 that holds data to be merged, and a sort process that performs merge sort. Section 13 and an output section 14 that sequentially outputs the data after the merge sort. The sort processing unit 13 includes a CPU (Central Processing Unit) (not shown) that executes processing according to a program, and a memory (not shown) that stores the program.

  FIG. 2 is a diagram illustrating a configuration example of the nth stage of the merge sorter according to the present embodiment. Here, if the length of the data sorted in the (n−1) th stage is N, N = 2 ^ (n−1).

  As shown in FIG. 2, the n-th merge sorter includes a counter 21, a label generation unit 22, registers R_ 0 to R_N, a comparison / selection unit 23, and a control unit 24. A CPU (not shown) in the sort processing unit 13 illustrated in FIG. 1 executes processing according to a program, whereby the counter 21, the label generation unit 22, the comparison selection unit 23, and the control unit 24 illustrated in FIG. 10 is virtually configured. Registers R_0 to R_N are included in the storage unit 12 shown in FIG.

  Hereinafter, the value counted by the counter 21 is set as c, and the label generated by the label generation unit 22 is set as L.

  When k is an arbitrary integer from 0 to N, each register R_k includes a field L_k for recording a label value given by the label generation unit 22 and a field v_k for recording comparison target data. .

  The counter 21 updates the count value c to “c + 1” every time data output from the (n−1) -th stage is input. The counter 21 resets the count value c to 0 when c = N.

  The label generation unit 22 assigns a label L to the data every time data output from the (n−1) -th stage is input. Further, the label generation unit 22 monitors the count value c, and when c = N, updates the label to be added to the data to the value of (L + 1) mod 4.

  The comparison / selection unit 23 stores the first half of the data sorted in the (n-1) -th stage and the latter half in the registers R_1 to R_N, and then the second half of the data is newly registered. Each time the data is stored in R_0, the first half data stored in the registers R_1 to R_k is compared with the value of v_N. When outputting in ascending order, the smaller value is used as the output value, and when outputting in descending order. The output value is a large value. The ascending order and descending order correspond to the rules relating to sorting, and in the present embodiment, description will be made on the case of outputting in ascending order.

  Specifically, the comparison / selection unit 23 refers to the field L_k of each register R_k, and <conditional expression (1)> “adjacent two values (L_k, L_ (k + 1)) (1, 0) or ( 3, 2) ”is checked. If there is a corresponding k, it is determined whether <conditional expression (2)>“ v_k <v_N ”is satisfied. If (2) is satisfied, the value of v_k is set as the output value. On the other hand, the comparison / selection unit 23 sets the value of v_N as the output value when the conditional expression (1) is not satisfied, or when the conditional expression (1) is not satisfied even if the conditional expression (1) is satisfied. Further, the comparison / selection unit 23 notifies the control unit 24 of the output result.

  The control unit 24 sequentially shifts and stores the labeled data in the registers R_1 to R_N. Further, when the output result received from the comparison / selection unit 23 indicates that v_k is output, the control unit 24 updates each value of the registers R_1 to R_k to the value of the register R_ (k−1). Further, when the received output result indicates that v_N is output, the control unit 24 updates each value of the registers R_1 to R_N to the value of the register R_ (k−1). Then, the control unit 24 updates the value of R_0 to the value x of the newly input data regardless of the output result.

  In the conventional online algorithm type merge sorter, in order to hold the data to be compared, two sets of storage devices including (2 ^ (n-1)) registers in the n-th stage, that is, (2 ^ n) Registers were prepared. In the worst case, two sets of this storage device are required, and all the data in one storage device must be output to the other storage device, and how much of the first half or the second half remains. This is because it changes for each process. However, in the middle of processing, both storage devices are free.

  On the other hand, in the configuration of the present embodiment, as shown in FIG. 2, R_0 to R_N are sufficient for the storage device, and one set of (2 ^ (n-1) +1) is included in the corresponding n-th stage. A storage device including a plurality of registers may be prepared. For this reason, in the present embodiment, the required amount of the storage device in each stage can be reduced, and the free space can be reused.

  In the present embodiment, the CPU (not shown) executes processing according to a program, so that the counter 21, the label generation unit 22, the comparison selection unit 23, and the control unit 24 are virtually configured in the information processing apparatus 10. However, some or all of these configurations may be configured by dedicated circuits.

  Next, the operation of the n-th merge sort by the information processing apparatus of this embodiment will be described. Here, the case where n = 3 will be described.

  FIG. 3 is a flowchart showing the operation procedure of merge sort by the information processing apparatus of this embodiment. Here, the case of sorting in ascending order will be described. When sorting in descending order, the determination formula “v_k <v_N” in step 106 of the flow shown in FIG. 3 may be replaced with “v_k> v_N”.

  The initial value of the count value c and the label L is set to 0, and the initial value of each field L_k (k = 0,..., N) is set to 0. The initial value of each field v_k (k = 0,..., N) is an invalid value and is arbitrary, but is set to 0, for example.

  Each time one piece of data output from the (n−1) -th stage is input, the sort processing unit 13 executes the operation flow shown in FIG. When data is input from the (n−1) th stage and this value is “x”, the counter 21 updates the count value c to “c + 1” (step 101). The counter 21 and the label generation unit 22 determine whether c = N (step 102). If c = N, the counter 21 resets the count value c, and the label generation unit 22 sets the label value. Is updated (step 102). In step 102, when c = N is not satisfied, the label L is not updated and the count value c is not reset.

  Subsequently, the sort processing unit 13 determines whether to update the information recorded in the registers R_0 to R_N illustrated in FIG. 2 as follows.

  The control unit 24 sequentially shifts and stores the labeled data in the registers R_0 to R_N, and the comparison / selection unit 23 sets <conditional expression (1)> for the labels recorded in all the registers R_0 to R_N. It is determined whether or not the condition is satisfied (step 104). The comparison / selection unit 23 acquires the corresponding value of k.

  When there is k that satisfies the conditional expression (1), the comparison / selection unit 23 acquires the corresponding k, and determines whether or not the value of v_k corresponding to the acquired k satisfies <conditional expression (2)>. (Step 105). When the conditional expression (2) is satisfied, the comparison / selection unit 23 sets the value of v_k as the output value y and notifies the control unit 24 of the output result. The control unit 24 updates the value held in each of the registers R_1 to R_k to the value held in the register R_ (k−1) based on the output result received from the comparison / selection unit 23. At that time, the control unit 24 stores the value of the label L given by the label generation unit 22 in the field L_0 of the register R_0, stores the value of x in the field v_0, and updates the register R_0 (step 106). . The data stored in the register R_ (k−1) is shifted to the register R_k. As a result, data is shifted between the registers toward the register R_N while maintaining the ascending order.

  For example, when the value held in v_1 of the register R_1 becomes the output value y, the value held in the register R_1 is updated to the value held in the register R_0, and the value x of the newly input data Is stored in the field v_0 of the register R_0.

  On the other hand, if the conditional expression (1) is not satisfied in the determination in step 104, or if the conditional expression (2) is not satisfied in the determination in step 105 even if the conditional expression (1) is satisfied, the comparison / selection unit 23 determines that v_N Is set as an output value y, and the output result is notified to the control unit 24. The control unit 24 updates the value held in each of the registers R_1 to R_N to the value held in the register R_ (k−1) based on the output result received from the comparison / selection unit 23. At that time, the control unit 24 stores the value of the label L given by the label generation unit 22 in the field L_0 of the register R_0, stores the value of x in the field v_0, and updates the register R_0 (step 107). .

  In this way, the n-th merge sorter counts the data input from the (n−1) -th stage by the counter 21, adds the label L, and registers R_0 to R_N according to the above-described logical determination. Are sequentially stored and updated, so that two data series that have been sorted by N = 2 ^ (n-1) are merged in ascending order, and one data series that has been sorted by 2 ^ n. Is generated.

  Next, a specific example of the procedure shown in FIG. 3 will be described with reference to FIGS.

  FIG. 4 is a diagram illustrating an example of a time series of data to be input at the nth stage. FIG. 5 is a diagram illustrating an example of a time series of data to be output at the nth stage. In order to simplify the explanation, n = 3.

  The data series that becomes the input of the nth stage is obtained by concatenating two data series that have already been sorted with respect to the (2 ^ (n-1)) series. As shown in FIG. 4, the output when n = 3 is a concatenation of two data series composed of four sorted data.

  As shown in FIG. 5, the function achieved by the nth-stage merge sorter in the case of n = 3 is ascending order of two data series in which N = 4 (= 2 ^ (n-1)) are sorted. To generate one data series that has been sorted into 8 pieces (= 2 ^ n pieces).

  In the third-stage merge sorter, it is assumed that the data series shown in FIG. 4 is input immediately after initialization.

When data of value x = 2 is input at time t ₀ , the counter 21 performs counting. Since the initial value of the count value c is 0, the count value c becomes 1 by inputting this data. Subsequently, the counter 21 and the label generation unit 22 determine whether or not c = N. However, since c = N is not satisfied, the count value c = 1 is maintained. Further, the label generation unit 22 assigns a label L having an initial value 0 to the input data.

When data of the value x = 3 is input at the next time t _{0 + 1} , the control unit 24 stores “0” in the field L_0 of the register R_0 and stores data “2” in the field v_0. In this way, the first four data are sequentially stored in the register by time t _{0 + 3} .

At the time t _{0 + 4} , when the first four data are stored in the registers R_0 to R_3 as in [Equation 1], the data of the value x = 1 is input.

When data of value x = 1 is input, since c = N is established, the label L is updated. When data of the value x = 5 is input at the next time t _{0 + 5} , the control unit 24 stores “1” in the field L_0 of the register R_0 and stores data “1” in the field v_0. The values held in the registers R_0 to R_4 are as shown in [Formula 2].

  When data of value x = 5 is input, referring to [Equation 2], since conditional expression (1) is satisfied at k = 0, and <conditional expression (2)> is also satisfied, v_0 = 1 Is output as y. In step 106, only register R_0 is updated. As a result, the values held in the registers R_0 to R_4 are as shown in [Formula 3].

Thereafter, every time data of value x is input until time t _{0 + 12} , the sort processing unit 13 executes the operation flow shown in FIG. The values held in the registers R_0 to R_4 and the output value y at times t _{0 + 6 to} t _{0 + 12} are shown in [Expression 4] to [Expression 10]. Note that data values not shown in FIG. 4 are represented by “*”.

  At the next time, the value of “* 1” stored in v_4 is compared with the value of “* 5” stored in v_0. Thereafter, in the third stage, the sort processing unit 13 performs the third stage processing on the input having the same cycle as in FIG. 4 that arrives without interruption, and generates the output in the same cycle as in FIG. This output is the fourth stage input.

  As described above, it is understood that the merge sort process is performed by the registers R_0 to R_4, that is, the (2 ^ (n-1) +1) registers (storage devices) in the nth stage.

  In this embodiment, when the merge sort online algorithm is implemented, by sharing the storage devices required for storing the first half data and the second half data, the required amount of the storage device can be almost halved. It is possible to reduce the amount of equipment required. As a result, an increase in hardware with respect to an increase in processing targets can be mitigated.

(Second Embodiment)
The present embodiment is a case of a configuration different from the merge sorter described in the first embodiment. Note that the entire information processing apparatus of the present embodiment is the same as the apparatus shown in the block diagram of FIG. 1, and in this embodiment, detailed description of the same configuration as that of the first embodiment is omitted. Differences from the first embodiment will be described.

  The configuration of the merge sorter of this embodiment will be described. FIG. 6 is a block diagram showing a configuration example of the nth stage of the merge sorter of this embodiment.

  As shown in FIG. 6, the n-th merge sorter includes a label generation unit 31, registers R_0 to R_N, a control unit 32_k, a selector 33_k, a bus 34, a comparison / selection unit 35, and a distribution unit 36. Have.

  A CPU (not shown) in the sort processing unit 13 illustrated in FIG. 1 executes processing according to a program, whereby the label generation unit 31, the control units 32_0 to 32_N, the selectors 33_0 to 33_N, the bus 34, and the distribution illustrated in FIG. The unit 36 and the comparison / selection unit 35 are virtually configured in the information processing apparatus 10. Registers R_0 to R_N are included in the storage unit 12 shown in FIG.

  The label generation unit 31 includes a counter 21 that counts the count value c and a label generation unit 22 that generates a label L, and has a function of updating these values.

  The register R_k has a field L_k for holding a label L and a field v_k for holding data to be compared. In the case of k = 2 to N, the input of each register R_k is connected to the output of the register R_ (k−1).

  The control unit 32_k sequentially shifts and stores the labeled data in the registers R_0 to R_N, checks whether or not the conditional expression (1) is satisfied, checks whether (L_k, L_ (k + 1)) satisfies the conditional expression (1 ) Is sent to the selector 33_k to control the selector 33_k. Specifically, when the conditional expression (1) is satisfied, the control unit 32_k transmits a first control signal indicating “true” to the selector 33_k, and when the conditional expression (1) is not satisfied, A second control signal indicating “false” is transmitted to the selector 33_k. As shown in FIG. 6, the control signals output from the control units 32_0 to 32_N are also transmitted to the comparison / selection unit 35.

  Further, the control unit 32_k updates the data held in the register R_k in accordance with the comparison result of the comparison / selection unit 35, as in the first embodiment. Details of this update process will be described later.

  The selector 33_k selects and outputs the value v_k or 0 of the register R_k according to the control signal received from the control unit 32_k. Specifically, the selector 33_k outputs the value of v_k of the register R_k when receiving the first control signal from the control unit 32_k, and outputs the value of 0 when receiving the second control signal from the control unit 32_k. To do.

  The bus 34 calculates the logical sum of the outputs of the selectors 33_0 to 33_N and outputs the logical sum to the comparison / selection unit 35. V_k corresponding to k that satisfies the conditional expression (1) is provided to the comparison / selection unit 35 via the bus 34.

  The comparison selection unit 35 determines the output value y based on the value of v_N, the control signal from the control unit 32_k, and the output value of the bus 34, and outputs the comparison result d to the distribution unit 36. Specifically, the comparison / selection unit 35 determines whether the conditional expression (1) is true or false based on the control signal received from the control units 32_0 to 32_N, and if there is true, the value of v_k received from the bus 34 and the register The v_N values of R_N are compared to determine whether or not the conditional expression (2) is satisfied, and the value of v_N or v_k is output as y. Further, the comparison / selection unit 35 outputs the determination result of the conditional expression (2) to the distribution unit 36 as the comparison result d.

  For example, when arranging data in ascending order, when v_k <v_N, the comparison result d is true, and the comparison / selection unit 35 sets the value of v_k as the output value y. When v_k <v_N is not satisfied, the comparison result d is false, and the comparison / selection unit 35 sets the value of v_N as the output value y.

  The distribution unit 36 distributes the comparison result d received from the comparison / selection unit 35 to the control units 32_0 to 32_N.

  Here, a method of updating the value stored in the register R_k by the control unit 32_k will be described.

  The control unit 32_k receives the determination result of the conditional expression (2) from the distribution unit 36 as the comparison result d, and the determination result of the conditional expression (2) is true and the determination result of the conditional expression (1) is true For k satisfying conditional expression (2), the value of the register R_k equal to or less than k is updated to the value of R_ (k−1), and the register R_0 is updated to (L, x) of the input data. To do. The input of each register R_k of all the registers is connected to the output of the register R_ (k−1), and the value is used for updating.

  On the other hand, when the determination result of the conditional expression (1) is false or when the determination result of the conditional expression (2) is false, all the control units 32_0 to 32_N have all the registers R_1 to R_N. The value of the register is updated to the value of the register R_ (k−1), and the register R_0 is updated to (L, x) of the input data. The input of each register R_k of all the registers is connected to the output of the register R_ (k−1), and the value is used for updating.

  Note that L_ (N + 1) used as a determination target by the control unit 32_N does not need to be prepared as R_ (N + 1), and only L_ (N + 1) or a fixed value “3” or “1” is set. , Can cancel the boundary condition. In addition, since v_k corresponding to the selector 33_N corresponds to v_N and is not an essential configuration in this embodiment, the illustration is omitted.

  Furthermore, in the present embodiment, a CPU (not shown) executes processing according to a program, whereby the label generation unit 31, the control units 32_0 to 32_N, the selectors 33_0 to 33_N, the bus 34, the distribution unit 36, and the comparison selection unit 35. However, some or all of these configurations may be configured by dedicated circuits.

  The merge sorter shown in FIG. 6 has the same function as the merge sorter shown in FIG. 2, and the same processing as the operation flow shown in FIG. 3 is also executed in this embodiment. The detailed description about is omitted.

  Also in this embodiment, the same effect as the first embodiment can be obtained. Further, in the present embodiment, as shown in FIG. 6, the n-th stage is composed of (2 ^ n + 1) structural units, and the structural units are the same regardless of which stage. Therefore, if this structural unit is prepared in advance, a predetermined n-th stage can be configured immediately according to demand. In other words, the design of the part storing the data to be sorted in each stage of the merge sorter does not change depending on the stage of the sorter in which the part is used, and can be made common to any stage. By standardizing the standards of the component parts of each stage, it is possible to quickly execute a design change when configuring a predetermined stage as necessary.

DESCRIPTION OF SYMBOLS 10 Information processing apparatus 12 Storage part 13 Sort processing part 21 Counter 22, 31 Label generation part 23, 35 Comparison selection part 24, 32_0-32_N Control part 33_0-33_N Selector 36 Distribution part

Claims (5)

An information processing apparatus that merges and sorts stream data using an online algorithm,
A storage unit that stores at least the first half part of the data consisting of the first half part and the second half part, which is input as the stream data and sorted separately in advance according to a predetermined rule;
A sort processing unit that outputs a merge sort of the data of the latter half and the first half, and
The sort processing unit is an information processing apparatus in the storage unit that is shared by an area for storing the first half part and an area for storing the second half part. The information processing apparatus according to claim 1,
The storage unit is arranged in a predetermined order, and has a plurality of registers for storing data whose number of data is “the number of data in the first half + 1”.
The sort processing unit
The first half of the data is sequentially shifted and stored in the plurality of registers according to the predetermined rule, and each time the second half of the data is input, the first of the plurality of registers is in the first order. Store the data in a register, compare the size of the first data in the latter half with the data stored in the last register in the order, and select and output one data based on the predetermined rule An information processing apparatus that shifts data remaining in the storage unit from one register to another toward the last register in the order. The information processing apparatus according to claim 2,
The sort processing unit
A counter that counts the number of input data;
A label is attached to the input data, and a label generator that updates the label when the count value of the counter reaches a predetermined value;
When the labels of two pieces of data that are adjacent to each other in the input order satisfy a predetermined condition, among the data of the plurality of registers, the first data in the second half part and the data stored in the last register in the order If the labels of the two data do not satisfy a predetermined condition, the order is stored in the last register. A comparison selection unit for outputting data;
An information processing apparatus comprising: a control unit that shifts the data remaining in the storage unit based on an output result of the comparison / selection unit to shift the register toward the last register in the order. The information processing apparatus according to claim 2,
The sort processing unit
A label generation unit that counts the number of input data and assigns a label to the data, and updates the label when the count value reaches a predetermined value;
A plurality of selectors and a plurality of control units provided corresponding to the plurality of registers;
A bus for outputting a logical sum of outputs of the plurality of selectors;
The control signal received from the plurality of control units determines whether to compare the size of the data received from the bus and the data stored in the last register in the order, and the result of the comparison or the control A comparison / selection unit for determining data to be output based on the signal;
A distribution unit that outputs a comparison result of the comparison selection unit to the plurality of control units,
Each of the plurality of control units outputs the control signal indicating whether or not the label of two data of a register adjacent to the corresponding register satisfies the predetermined condition to the corresponding selector and the comparison / selection unit And determining whether or not to shift the data stored in the corresponding register to the next register based on the control signal and the comparison result,
Each of the plurality of selectors selects data stored in a corresponding register or 0 according to the control signal received from the corresponding control unit, and outputs the selected data to the bus.
The comparison / selection unit stores the data received from the bus and the order in the last register when any one of the control signals received from the plurality of control units satisfies the predetermined condition. If the control signal does not satisfy the predetermined condition, the order is stored in the last register. An information processing device that outputs data. An information processing method by an information processing device that performs merge sort on stream data using an online algorithm,
Of the data consisting of the first half part and the second half part separately sorted in advance according to a predetermined rule, the data of the first half part input as the stream data is stored in the storage unit of the information processing apparatus,
Merge sort and output the latter half of the data input as the stream data and the first half of the data stored in the storage unit,
An information processing method in which, when performing the merge sort, an area for storing the first half part and an area for storing the second half part are shared in the storage unit.