JP2699738B2 - Overhead information calculation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead information calculating method for automatically calculating, by static analysis, information on overhead time when dynamic analysis information of a program created in a high-level programming language is collected. is there.

[0002]

2. Description of the Related Art Dynamic analysis using a predetermined tool is performed for the purpose of evaluating the execution performance of a program.
The measurement points for collecting the dynamic analysis information include a specific measurement point such as a program unit and a DO loop determined by the dynamic analysis mechanism, and a specific point specified by the user.

By the way, in order to collect dynamic analysis information, an execution time for information collection called an overhead time is required, and when measurement is performed within a limited time, the value is set in advance. It is important to understand.

However, the exact amount of overhead time cannot be known without actually executing a program, and cannot be easily obtained.

In order to predict the overhead time, the user analyzes the execution path from the source list or the cross-reference list of the variable names obtained by statically analyzing the source program to the measurement location, and executes each analysis. In addition to calculating the number of executions, the overhead time per execution was measured, and the result was multiplied to calculate the overhead time for each measurement point. Note that the overhead time per execution has a different value depending on the type of information to be collected.

[0006]

As described above, conventionally, in order for a user to predict the overhead time of a measurement location, various types of information are collected, the execution path of the measurement location is analyzed, and the number of executions is reduced. It has to be calculated and weighted according to the type of information to be collected, and the calculation has to be performed, and there is a disadvantage that the work of the user is very complicated.

[0007] In addition, since the work is complicated, when the program is executed without knowing the overhead time due to the collection of the execution information, an enormous amount of execution time is consumed if the measurement location is in a loop having a large number of loops. There were also problems.

The present invention has been proposed in view of the above points, and an object of the present invention is to provide an overhead information calculation method capable of automatically calculating overhead information.

[0009]

According to the present invention, in order to achieve the above object, a source program and information collection information are input, and a loop structure and a structure related to a control branch in the source program are statically analyzed. Means for generating program structure information by calculating the number of executions for each measurement location based on the generated program structure information, and taking into account the weight of the overhead set for each type of information to be collected. Overhead information calculation means for calculating information, and if the information required to calculate the number of executions of the measurement location is undefined, display those undefined information and input the value, or display the undefined information And an indefinite information input means for searching for a value required to calculate the number of executions from the input information on the undefined value without performing It has to.

[0010]

According to the overhead information calculation method of the present invention, the program structure analysis means inputs a source program and information collection information and statically analyzes a loop structure and a control branch structure in the source program. To generate program structure information. The overhead information calculation means calculates the number of executions for each measurement location based on the generated program structure information, and calculates overhead information in consideration of the weight of the overhead set for each type of information to be collected. In addition, if the information necessary for calculating the number of executions of the measurement location is undefined, the undefined information input means may display such undefined information and input the value, or display the undefined information. Instead, a value necessary for calculating the number of executions is searched from the input information on the indefinite value.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an overhead information calculation method according to the present invention.

Referring to FIG. 1, in the present embodiment, a source program 1 and information collection information 2 are inputted, uncertain information 8 is presented as necessary, and uncertain value information 9 is inputted, and overhead information 10 is calculated. And a static characteristic analysis mechanism 3 for outputting the data.

The source program 1 is a program described in a high-level programming language such as the FORTRAN language, and is composed of a plurality of program units such as a main program and subroutines. In addition, information collection information 2
The information includes information on the location where information is collected (measurement location) and information on the type of information to be collected (for example, execution time).

The static characteristic analysis mechanism 3 analyzes the source program 1 to generate program structure information 5, and calculates overhead information by referring to the generated program structure information 5. It includes an overhead information calculation means 6 and an indefinite information input means 7 for inputting from the user when there is indefinite information (for example, the number of loops specified by a variable and not specified) in calculating the overhead information. .

Hereinafter, the operation of the above embodiment will be described with reference to specific examples.

The program structure analyzing means 4 inputs the source program 1 and the information collection information 2 and calls program-based call statements (such as CALL statements and function calls) from the source program 1, loop control and branch control. (DO statement, IF block statement, GOTO statement, etc.), statement with control transfer (sentence with defined statement number, ENDI
An F sentence, etc.) and a measurement location for collecting execution information are searched, and necessary information is extracted.

Also, a control flow analysis is performed based on information of a statement for performing loop control, a statement for performing branch control, and a statement for which control is to be moved, and a loop structure and a control transfer destination are specified.

The program structure analyzing means 4 compiles these analysis results as program structure information 5.

After the analysis of all the program units included in the source program 1 is completed, the calling relationship between the program units is analyzed, and the result is held.

FIG. 2 shows an example of a source program 1 described in the FORTRAN language.

The program unit 1A is a main program named "AAA", and includes a call statement 101, 103, 105 for each program, a loop control statement 102 constituting a DO loop, and a statement 104 having control transfer. Contains.

The program unit 1B is a subroutine named "BBB", and includes a statement 106 and a branch control statement 113 having a transfer of control constituting a loop, loop control statements 107, 108, 110 constituting a DO loop. Statements 109, 111, and 112 that include a transfer of control are included.

The program unit 1C is a subroutine named "CCC", and includes a branch control statement 114 constituting an IF block, a statement 117 having control transfer, and D
It includes loop control statements 115 and 118 constituting the O-loop and statements 116 and 119 with control transfer.

On the other hand, for the source program 1 to be measured, the information collection information 2 specifies all the CALL statements and DO statements as information measurement locations, and instructs the measurement locations to measure the execution time. It is assumed that

First, the program structure analysis means 4 inputs the program unit 1A, detects the call statement 101 of the program unit, and identifies the type of call statement "CALL" of the program unit and the program unit name "BBB" to be called as additional information. Is registered in the program structure information 5A corresponding to the program unit 1A as shown in FIG. In addition, since the call statement 101 for each program is also a target of information collection, the fact that it is a measurement location is also registered in the program structure information 5A.

Next, when the loop control statement 102 is detected, information such as the type "DO loop", statement number "10", control variable "I", initial value "1", end value "20", increment value "1", etc. Is registered as additional information in the program structure information 5A.

The call statement 103 for each program is processed in the same manner as the call statement 101 for each program.

Next, when a sentence (sentence or the like in which a sentence number is defined) 104 having a control shift is detected, the type “lab” is detected.
"el" and the statement number "10" are registered in the program structure information 5A.

The call statement 105 for each program is processed in the same manner as the call statements 101 and 103 for each program.

After the analysis of the program unit 1A is completed, referring to the attached information on the program structure information 5A of the statement 104 having the control transfer and the loop control statement 102, the same statement number "1" is used.
Since it has "0", it is determined that the loop structure exists, and the entry number "4" in the program structure information 5A is registered as the loop information of the loop control statement 102.

Similarly, FIGS. 4 and 5 show program structure information 5B and 5C obtained by analyzing the program units 1B and 1C.

Here, in the program unit 1B, a loop is formed between entry numbers "1" and "8", "2" and "7", "3" and "4", and "5" and "6". It turns out that it is. It is also found that a loop is formed between the entry numbers “1” and “4”, “2” and “3”, and “5” and “6” in the program unit 1C.

Next, the program structure analyzing means 4 generates program structure information 5A, 5B, 5C for each program unit.
Associate the calling relationship between program units based on
As shown in FIG. 6, it is recognized that the program unit 1A calls the program unit 1B twice and the program unit 1C calls once.

Next, returning to FIG. 1, the overhead information calculation means 6 executes the execution of each measurement point when each program unit is executed once based on the program structure information 5 generated by the program structure analysis means 4. Calculate the number of times. This is the number of executions when the main program is executed once in a program unit, and the number of executions when the call is executed once in a subroutine program unit.

Next, overhead information calculating means 6
Calculates the number of calls per program for each call path per program and adds it to calculate the number of calls per program. The number of calls per program and the number of executions at each measurement point in one call The total number of executions for each measurement location is calculated by multiplication. Note that the number of calls of the main program in the program unit is one.

Next, overhead information calculating means 6
Calculates the overhead time for each measurement location by multiplying the total number of executions at each measurement location by the overhead time per execution determined by the type of information to be collected.

Then, the overhead information calculating means 6
Calculates the overhead time for each program unit or for the entire program by adding the overhead time for each measurement point, and outputs it as overhead information 10 to the outside.

In the processing of the overhead information calculating means 6, if there is information (number of loops, etc.) necessary for calculating the number of executions and information having an indefinite value,
The indefinite information input means 7 is called.

The indefinite information input means 7 displays the indefinite information 8 on a display or the like, and allows the user to input it as indefinite value information 9. Further, a value required for calculating the number of executions may be searched from the separately input indefinite value information 9 without displaying the indefinite information 8.

It is also possible to set a predetermined value as the assumed value for the indefinite information without providing the indefinite information input means 7. In this case, although the overhead information finally calculated includes an error, the overhead information can be simplified, and is suitable when rough prediction is sufficient.

The operation of the overhead information calculating means 6 for the source program 1 shown in FIG. 2 is as follows.

The overhead information calculation means 6 firstly
The program structure information 5A shown in FIG. 3 is searched for the one designated as the measurement location, and the measurement location 101 is detected first. In the description, the number of the sentence in the source program 1 described above is used as the code indicating the measurement location.

Judging from the program structure information 5A of FIG. 3, the loop structure included in the program unit 1A has only the entry number between "2" and "4",
Since 01 is not included in either the branch control or the loop control, the number of executions is one.

Similarly, the number of executions of the measurement point 102 is one. The entrance and exit of the loop are not considered to be inside the loop.

Since the measurement point 103 is in the loop structure, the number of executions is "20" which is the number of loops of the loop structure. The number of loops can be obtained from the additional information of the program structure information 5A.

Similarly, the number of executions of the measurement point 105 is one.

Next, FIG. 4 corresponding to the program unit 1B
For the program structure information 5B of FIG.
The number of executions for 108 and 110 is calculated.

Here, the measurement points 107, 108, 110
Since the number of loops between the label having the entry number “1” and the branch having the entry number “8” is included in an indefinite loop, the number is set to α. Measurement point 1
08 and 110 are included in a loop having an indefinite number of loops M between the DO loop having the entry number “2” and the label having the entry number “7”. Therefore, the number of executions of the measurement point 107 is α times, and the number of executions of the measurement points 108 and 110 is α *
M times.

Similarly, for the program structure information 5C of FIG.
The number of executions for 5,118 is calculated.

Since the measurement point 115 is included in the branch control between the branch of the entry number “1” and the ENDIF of the entry number “4”, if the branch rate is β, the number of executions is β Times. Also, the number of executions of the measurement point 118 is one.

The overhead information calculation means 6 activates the indefinite information input means 7 and inputs the above α, M, β,
Alternatively, it is determined by searching from separately input information. If the indefinite information input means 7 does not exist,
Assumes a value of its own. The overhead time calculated by assuming the number of loops and the like to be the minimum value can be regarded as the minimum overhead time.

In the above example, α = 1, M = 10, β = 0.5
The calculation result of the number of times of execution when it is determined is shown in the middle column of FIG.

Next, the overhead information calculating means 6
The number of calls for each call path is calculated for each program, and the sum is added to calculate the number of calls for each program.

In the case of the program unit 1A, the number of calls is one because of the main program.

In the case of the program unit 1B, the call path is the program unit call statement 1 of the program unit 1A.
Since there are two paths 01 and 103 (see FIG. 2) and the number of executions of each call statement is 1 and 20, the number of calls of the program unit 1B is 21.

In the case of the program unit 1C, the call path is the program unit call statement 1 of the program unit 1A.
Since the number of executions of the call statement is one, the number of calls of the program unit 1C is one.

Next, the overhead information calculating means 6
By multiplying the number of executions for each measurement point by the number of executions for each program including the measurement point, the total number of executions for each measurement point is calculated.

The calculation result of the total number of executions for each measurement point in the above example is shown in the right column of FIG.

Next, the overhead information calculating means 6
The overhead time for each measurement point is calculated by multiplying the total number of executions for each measurement point by the overhead time for one execution in accordance with the type of information to be collected. Here, the overhead time per execution is
A fixed value may be set, or a value determined by executing an average program for actually collecting information in advance may be used.

In this example, since it is instructed to measure the execution time for each measurement point, the overhead time can be uniformly set to t, and the total number of executions in FIG. 7 is multiplied by t. The value is the overhead time for each measurement point.

Then, the overhead time for each program unit and the overhead time for the entire program can be calculated from the overhead time for each measurement point. In the example of FIG. 7, the overhead time of the entire program is 465.5 * t time.

[0063]

As described above, the overhead information calculation method of the present invention has the following effects.

Since the overhead information of the measurement location can be automatically calculated, the user does not need to perform a complicated process of collecting various information and calculating the overhead time, and can easily predict the overhead time. Can be

By using the calculated overhead information, it is possible to easily select a measurement point such as excluding a measurement point that requires a large amount of overhead time from a measurement target, and to avoid unnecessary execution.

If the overhead information includes an indeterminate element that cannot be determined only by static analysis of the source program, information on the indeterminate element can be obtained from the user, so that more accurate overhead information can be calculated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of an overhead information calculation method according to the present invention.

FIG. 2 is a diagram illustrating an example of a source program.

FIG. 3 is a diagram illustrating an example of program structure information.

FIG. 4 is a diagram showing an example of program structure information.

FIG. 5 is a diagram showing an example of program structure information.

FIG. 6 is a diagram illustrating an example of a calling relationship between program units.

FIG. 7 is a diagram illustrating an example of calculation results of the number of executions and the total number of executions for each measurement location.

[Explanation of symbols]

 1 ... Source program 1A, 1B, 1C ... Program unit 2 ... Information collection information 3 ... ... Static Characteristic analysis mechanism 4 Program structure analysis means 5, 5A, 5B, 5C Program structure information 6 Overhead information calculation means 7 ………………………………………… ·················································· Overhead information

Claims (2)

(57) [Claims] 1. A program structure analysis means for inputting a source program and information collection information and statically analyzing a loop structure or a structure related to a control branch in the source program to generate program structure information. Information calculating means for calculating the number of executions for each measurement location based on the program structure information obtained, and calculating overhead information in consideration of the weight of the overhead set for each type of information to be collected. Overhead information calculation method. 2. When information necessary for calculating the number of executions of a measurement location is uncertain, display the uncertain information and input the value, or input the value without displaying the uncertain information. 2. The overhead information calculation method according to claim 1, further comprising an indefinite information input means for searching a value required to calculate the number of executions from the information on the determined indefinite values.