JPH0217540A - Constant registering processing method - Google Patents

Abstract

PURPOSE:To reduce a constant storing area by adding and registering a noncoincident part only when the continuous part of the head of data to be newly registered and the continuous part of the end of the registered data are coincident. CONSTITUTION:When a constant registering request is received from a source program, the registered data are taken out of a constant storing area digit by digit, successively retrieved, the address of the head of data is stored into a register for a work and the data of one byte of the address are read. Next, the data are compared with one byte of a constant to receive the registration request, and when they are coincident, the next type of the registration constant is compared with the next byte of the constant storing area and this is repeated. When the completion of the registered data is detected, the part of the remainder of data registered is continuously added and registered after the registered data.

Description

[Detailed Description of the Invention] [Summary] Regarding the processing of a compiler that translates a computer source program into a target program, a constant storage area on the target program is used to hold constant data written in the source program. When a source program is translated to generate an object program that is executed on a computer, data representing constants written in the source program is provided in the object program. In the computer process for registering data in the constant storage area, it searches for a match between the continuous part at the beginning of the data to be newly registered and the continuous part at the end of the data registered in the constant storage area, and If a match is found and the data to be registered has a remaining part after removing the first continuous part, only the remaining part is registered in the area following the last continuous part of the constant storage area. Configure.

[Industrial Application Field] The present invention relates to the processing of a compiler that translates a computer source program into a target program, and in particular, the processing of a compiler that translates a computer source program into a target program, and in particular, the processing of constants for registering constant data written in the source program in a constant storage area of the target program. Regarding registration processing method.

In the process of translating a source program written in the C0BOL programming language etc. in a computer to generate a target program to be executed on the required computer, if constants such as numerical values are written in the source program, Collecting and registering the data of these constants in a constant storage area provided on the target program, and generating the target program so that the required program step refers to the data in the required part of the constant storage area is as follows: As is well known.

[Conventional technology]

FIG. 2 shows an example of the configuration of a computer that performs translation processing of a source program. A compiler 1 executed on the computer inputs a source program 2 and performs translation processing, and a machine language generation unit 3 converts it into the required computer machine language. The target program 4 converted into the following program is output.

The source program 2 shown in FIG. 3 (al) is an example showing a part of a program written in the C0BOL language. For example, as is well known, the program statement 10 in the program executes the process of setting the constant r345 J to the variable A. show.

Here, variable A is defined in program statement 15, and program statement 15 indicates that variable A is 3-digit numerical data, so compiler 1 creates variables in target program 4 correspondingly. A is a 3-byte storage area (
(each 1-digit numeric data is 1 byte), set 3-byte data representing the constant r345J in an appropriate storage area, and transfer the contents of the constant storage area to the variable A storage area. Generate a machine language program to

For this purpose, the machine language generator 3 in Figure 2 is the source program 2.
When a constant written in is detected, it notifies the constant registration processing unit 5 of the registered constant, requests constant registration to set the constant in a storage area, and receives and receives the address of the storage area of the constant as a result of the processing. This is used as the address of the transfer source storage area of the machine language program for data transfer.

The constant registration processing unit 5 has a constant storage area 6 in its work area, and when it receives a request for constant registration, it sequentially stores the registered constants from the beginning of the constant storage area 6, and stores the first address of the stored registered constant. It is returned to the machine language generation unit 3.

However, at this time, the registered constants are compared with the data already registered in the constant storage area 6, and if part or all of the data and the constants completely match, the registered constants are saved without new registration. It is decided to use the matching part, and the first address of the matching part is returned as the address of the constant registration destination, thereby reducing the constant storage area 6.

For example, if there are constant descriptions like program statements 10 to 13 in source program 2 in FIG. 3(a),
Since the machine language generation unit 3 sequentially requests constant registration in the order in which they appear in the program, the constant registration processing unit 5 first registers r345.
Register J at the beginning of constant storage area 6. Next, when there is a registration request for r789J written in program statement 11, r
789 J is compared with r345 J, which has already been registered in constant storage area 6, and since they do not match, it is additionally registered in the position following r345 J in constant storage area 60. However, the following program statement 12
Since the constant r345J matches the registered data, no additional registration is performed and the first three digits of data are used as is.

The constant r457891J of the next program 13 matches the already registered data up to r45789J, but since a complete match cannot be obtained, r457891J is additionally registered, and the constant r345789J of program statement 14 matches the already registered data completely. Since there is a matching part, no additional registration will be made.

FIG. 4 shows the process flow of the constant registration processing unit 5. When a constant registration request is received, the registered data is transferred from the constant storage area 6 to 1.
Assuming that digits are retrieved and searched sequentially, first, the required control values are initialized, and in post-processing step 20, it is determined whether unsearched data remains in the constant storage area 6. including) immediate processing step 2
9, and the start address of the area registered in step 30 is returned to the machine language generation unit 3.

If there is data in constant storage area 6, process step 2
At step 1, the first address of the remaining data is stored in a working register, and at step 22, 1 byte of data at that address is read out.

In processing step 23, the receiver compares the first byte of the constant it has taken with the data read from the constant storage area 6, and if they do not match, it returns to processing step 20 and stores the constant at the address stored in the register. The end of area 6 is identified, and in this way, data matching the first byte of the registered constant is searched from the beginning of the data registered in constant storage area 6.

As a result, if there is matching data, the process proceeds from processing step 23 to processing step 24 to identify whether the registered constant has the next digit (in this case, the second byte), and if there is no matching data (in other words, the current (in the case of a 1-byte constant) is a case where there is a part that completely matches the registered constant in the registered data, so in processing step 28, the address (matching part) is stored in the register first. (address of the first byte) is returned to the machine language generation unit 3.

If the next digit remains in the registered constant, it is identified in processing step 25, and if the next data exists in the constant storage area 6, the next 1 byte is read out in processing step 26, and the next digit is read out in processing step 27. Compare with next byte. If the result is a mismatch, the process returns to step 20, and if registered data remains, the same process as above is repeated from the next byte.

If a match is found in processing step 27, the process returns to processing step 24, and in this way the next byte of the registered constant is compared with the next hide of the data registered in the constant storage area 6 to find a match. Repeat as long as possible until some data is completed. As a result, if the registered constant is completed first, if there is a portion in the registered data that completely matches the registered constant, the process proceeds from process step 24 to process step 28 as described above, and the process ends.

Also, if the data registered in constant storage area 6 finishes first,
This is a case where there is no completely matching part, and processing step 2
5, the process proceeds to step 29, where registration constants are additionally registered as described above.

After completing the constant registration for the entire source program as described above, the machine language generation section 3 incorporates the constant storage area 6 created by the constant registration processing section 5 into the area of the target program 4.

[Problem to be solved by the invention]

According to the above processing method, the registered constant data is used only when there is a part that completely matches the registered constant among the constant data registered in the constant storage area 6, and even if there is a partial match, it is not used at all. However, if you try to use already registered data as much as possible even if there is only a partial match,
Constant storage requirements can be further reduced.

An object of the present invention is to provide a constant registration processing method that can reduce the constant storage area on a target program for holding constant data written in a source program.

[Means to solve the problem]

FIG. 1 is a process flowchart showing the configuration of the present invention.

The figure shows the flow of constant registration processing. In processing steps 40 to 47, a case where a part of the registered constant matches the end of the registered data is detected. In that case, processing step 51 detects only the unmatched part of the constant. Register additionally.

[For production]

A process of registering data representing constants written in the source program in a constant storage area provided in the target program by the constant registration processing unit 5 when a source program is translated to generate a target program to be executed on a computer. I do.

In this case, the processing in steps 40 to 47 searches for a match between the continuous part at the beginning of the constant data to be newly registered and the continuous part at the end of the data registered in the constant storage area.

As a result, if a loss is obtained, and if there is a remaining part of the data to be registered except for the first continuous part, in processing step 51, only the remaining part is transferred to the last continuous part of the constant storage area. Register in the area following.

With the above processing method, when there is a partial match between the data to be registered and the registered data, the registered data can be used for part of the data, and the constant storage area can be reduced.

〔Example〕

The configuration of the computer is the same as that shown in FIG. 2, except that the constant registration processing section 5 of the compiler 1 executes the processing as shown in FIG. 1 according to the present invention.

When the constant registration processing unit 5 receives a constant registration request, it extracts the registered data one digit at a time from the constant storage area 6 and sequentially searches it as in the past, and first initializes the required control values in a post-processing step 40. It is determined whether unsearched data remains in the constant storage area 6, and if it does not, it is immediately additionally registered in a processing step 49, and the start address of the registered area is returned to the machine language generation unit 3 in a processing step 50.

If there is data in constant storage area 6, process step 4
In step 1, the first address of the remaining data is stored in the working register, in processing step 42, 1 byte of data at that address is read, and in processing step 43, the receiver stores the first byte of the received constant and the constant. The data read from area 6 is compared, and if they do not match, the process returns to step 40 to identify whether it is the end of constant storage area 6 and thus search for data that matches the first byte of the registered constant.

If there is matching data, the process proceeds to step 44 to identify whether the registered constant has the next digit, and if there is no matching data, the part that completely matches the registered constant is found in the registered data. Therefore, in step 48, the address is stored in the register and returned to the machine language generation unit 3.

If the next digit remains in the registered constant, it is determined in processing step 45 whether the next data exists in constant storage area 6, and if there is, the next 1 byte is read in processing step 46, and processing step 47 The registered constant is compared with the next byte of the registered constant, and if the result does not match, the process returns to step 40.

If a match is obtained in processing step 47, the process returns to processing step 44, and the comparison between the next byte of the registered constant and the next byte of data registered in the constant storage area 6 is proceeded in this way.

As a result, if the registered constant is completed first, in which case there is a part in the registered data that completely matches the registered constant, the process proceeds to step 48 and ends the process as described above.

In addition, if it is detected in processing step 45 that the registered data has ended, the last part of the registered data in the constant storage area 6 matches the part from the beginning to the middle digit of the data to be registered. It is. Therefore, in this case, the process proceeds from process step 45 to process step 51, and only the remaining part of the data to be registered except for the matching part is additionally registered following the registered data in constant storage area 6, and then process step At step 48, as described above, the address stored at step 41 (the address of the byte of the registered data that matches the first byte of the data to be registered) is returned to the machine language generation unit 3.

According to the above processing, for example, as shown in FIG. 3(b) for an example similar to the source program 2 in FIG. 3(a),
For the constant descriptions of program statements 10 to 13, the constant r345J of program statement 10 is registered at the beginning of the constant storage area 6, and then the constant r78 of program statement 11 is registered as before.
9 J is additionally registered in the position following r345 J in the constant storage area 6, and since the constant r345 J in the next program statement 12 matches the registered data, no additional registration is performed.

The constant r457891J of the following program 13 does not have a completely matching part in the registered data, but since the end of the registered data and the front part of the constant r45789J match, the unmatched part at the end of the constant is "1". will be additionally registered. The next program statement 14, r345789J, is not additionally registered as in the conventional case.

Therefore, as can be seen by comparing the constant storage area 6 of FIG. 3 (bl) with FIG. 3 (al), which is the result of this processing method,
The amount of storage space required is reduced.

Computer configuration example block diagram No. figure Diagram of constant registration No. figure

Claims (1)

[Claims] When a source program is translated to generate a target program to be executed on a computer, data representing constants written in the source program is registered in a constant storage area provided in the target program. Computer processing for (40-5
In 1), search for a match between the continuous part at the beginning of the data to be newly registered and the continuous part at the end of the data registered in the constant storage area (40 to 47), and if the match is found. , and if the data to be registered has a remaining part after excluding the continuous part at the beginning, register only the remaining part in the area following the continuous part at the end of the constant storage area (51). Characteristic constant registration processing method.