JPH01136239A - Program translation processing system - Google Patents

Abstract

PURPOSE:To shorten the execution time of the whole of program by performing the optimization processing of a non-recursive procedure by recognizing at the time of translation. CONSTITUTION:A translating auxiliary part 3 analyzes the cell structure of all of the procedures included in a source program, and recognizes the non- recursive procedure. Information with respect to the non-recursive procedure is provided to the translation part 7 of a translation processing part 2. And the translation part 7 performs a translation processing by which static area allocation can be performed on a stack on the non-recursive procedure. And it performs the translation processing by which an area allocated on the stack can be conformed to a return address on a recursive procedure.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a program translation processing method for a procedural programming language that allows recursive procedure calls.

The purpose is to recognize non-recursive procedures that can be determined during program translation, and to use these to perform optimized translation processing.

In a program translation processing method that has a translation unit that translates a source program written in a procedural programming language that allows recursive procedure calls, a temporary procedure that extracts the name of the procedure called by each procedure in the source program is used. With the translation department.

a graph creation unit that creates a call structure graph according to a predetermined rule based on the processing result of the temporary translation unit; and a recognition unit that recognizes a non-recursive procedure based on the call structure graph; When the source program is translated by the translation unit, the recognition result of the recognition unit is referred to so that non-recursive procedures in the source program are optimized.

[Industrial application field]

The present invention relates to a program translation processing method, and more particularly to a program translation processing method for a procedural programming language that allows recursive procedure calls.

For procedural programming languages, such as C language.

Some languages allow a procedure to call itself directly or indirectly.

[Conventional technology]

In order to implement recursive procedure calls, it is necessary to hold the address to which control should be returned after execution (return address). For this purpose, some space on the stack is allocated. Other required information is held on the stack in a form that corresponds to the return address.

By the way, just because a program is written in a language that allows recursive procedure calls does not necessarily mean that all procedures included in the program are called recursively.

However, in conventional program translation processing methods, even if a certain procedure is non-recursive, it is realized using the same method as a recursive procedure. That is, other necessary information is placed on the stack so as to correspond to the address of the procedure.

[Problem that the invention seeks to solve]

Non-recursive procedures (procedures that do not include recursive procedure calls) can also be realized by statically allocating an area on the stack, instead of using the prior art described above. That is, unlike recursive procedures, in non-recursive procedures, if the variable is the same, the entity to be referenced is the same at any point of reference.

Of the statically allocated areas on the stack, the area that should be referenced at that time can be referenced.

Incidentally, from the viewpoint of efficiency and optimization during program execution, it is often more advantageous to statically allocate areas.

Therefore, according to the above-mentioned conventional technology, although it is a non-recursive procedure that allows static area allocation, an extra burden is generated at the time of execution. In other words, extra processing to perform processing similar to a recursive procedure even though it is not a recursive procedure.

Due to the insufficient optimization resulting from such processing, there are problems in that the recursive call processing causes overhead and program execution cannot be optimized.

SUMMARY OF THE INVENTION An object of the present invention is to provide a program translation processing method that can recognize non-recursive procedures that can be determined at the time of program translation and perform optimized translation processing using these procedures.

c. Means for Solving Problems] FIG. 1 is a diagram showing the principle structure of the present invention, and shows a program translation (support) system according to the present invention.

In FIG. 1, l is a processing device, 2 is a translation processing unit, and 3 is a translation assistant (3) that supports optimal translation in the translation processing unit 2.
4 is a temporary translation unit, 5 is a graph creation unit, 6 is a recognition unit, 7 is a translation unit (compiler) that actually translates (compiles) the program, 8 is a source program, and 9 is an object module. .

A source program 8 written in a procedural programming language that allows recursive procedure calls is input to the temporary translation section 4 and the translation section 7 of the translation processing section 2 .

The temporary translation unit 4 extracts the name of the procedure called by each year's continuation for all procedures involving a procedure call included in the source program 8, and uses this as a call information table.

The graph creation unit 5 analyzes the call structure based on the call information table and creates a call structure graph.

This call structure graph is created according to predetermined rules based on the analysis results.

The recognition unit 6 recognizes non-recursive procedures based on the call structure graph and creates a non-recursive procedure list. This recognition is performed in such a way that if the call structure graph does not have a predetermined shape (structure), it is recognized as a non-recursive procedure. Note that the predetermined structure here refers to a loop structure that appears in a call structure graph when a procedure is called by another procedure called by another procedure (described later).

The translation unit 7 analyzes the source program 8 to generate an object code, and edits this to create an object module 9.

At this time, non-recursive procedures are distinguished from recursive procedures by the non-recursive procedure list, and optimal object codes are generated for each.

[For production]

When translating a program, it is impossible to tell whether a procedure is called recursively just by looking at its definition (declaration), except in special cases such as procedures that do not include a single procedure call. Can not.

Therefore, a translation auxiliary unit 3 is provided, and this translation auxiliary unit 3 analyzes the call structure (structure that indicates the calling relationship of Jinbei continuations to each other) for all procedures included in the source program 8. , which allows us to recognize non-recursive procedures. Then, information about this non-recursive contracting procedure is transmitted from the translation assisting section 3 to the translation processing section 2.
(translation unit 7), an optimized object module 9 can be obtained.

That is, the translation unit 7 performs translation processing such as static area allocation on the stack for non-recursive procedures. On the other hand, for recursive procedures, translation processing is performed such that the area allocated on the stack corresponds to the return address.

Such processing in the translation unit 7 makes it possible to optimize the non-recursive procedure portion, thereby improving the execution efficiency of the entire program.

Note that a procedure that does not include one procedure call can be easily recognized as a non-recursive procedure.

The recognition may be performed in the recognition unit 6 like the others, or it may be performed only in the translation unit 7, without interfering with optimal translation processing.

〔Example〕

FIG. 2 is an explanatory diagram of an embodiment, and shows an example of program translation processing according to the present invention.

In FIG. 2, 10 is a call information table, 11 is a call structure graph, and 12 is a non-recursive procedure list.

The source program 8 is written in a procedural programming language 9, for example C language, which allows recursive procedure calls, as shown in FIG.

In the temporary translation section 4, it is checked whether all procedures in the source program 8 created by two people involve one procedure call, and if there are five procedure calls, what are the names of the procedures being called. Through this process, the temporary translation unit 4 creates the call information table 10.

In the source program 8, the procedure proc O calls the procedure proc l, so it is indicated in the call information table 10 as rprocO:proclJ (the same applies to other procedures), -
Since method 1 procedure proc 2 does not call any other procedure, procedure 1 procedure pr in the call information table IO
No description is given of the procedures that oc2 calls.

The graph creation unit 5 uses the input call information table IO
A call structure graph 11 is created from

Call structure graph 11 is a directed graph that follows the following predetermined rules or definitions.

(i) Procedures are associated with nodes (in Figure 2, each node is indicated by a procedure name).

(ii) A procedure corresponding to a certain node A is executed by another node B.
If the procedure corresponding to is called.

Write an arrow (arc) pointing from node A to node B.

Two descriptions in the call information table 10.

rproc O: proc I J and rproc
1: A loop structure is formed between proco and proc 1 in the call structure graph 11 according to proc OJ. on the other hand.

For proc 2, no loop structure is formed because proc 2 does not call proc O or proc 1.

The recognition unit 6 creates a non-recursive reduction procedure list 12 based on the call structure graph 11 input in the form of an appropriate internal representation.

Recognition of non-recursive procedures in the recognition unit 6 is performed as follows.

(i) A loop structure existing in the call structure graph 11 (
strongly connected region (5CR) (recognizes it as a recursive procedure).

(ii) A procedure corresponding to a point not included in any loop structure is recognized as a non-recursive procedure.

The recognition unit 6 recognizes that the procedure proc 2 corresponding to the point in the call structure graph 11 that does not form a loop structure is a non-recursive procedure. and.

The procedure name of this procedure proc 2 is registered (output) in the non-recursive procedure list.

Translation processing is performed on the source program 8 written by five people in the translation section 7 while referring to the non-recursive procedure list 2 input in the same manner.

Procedure proc O and pr in source program 8
Regarding oc 1, the translation unit 7 learns that the procedure name does not exist in the non-recursive procedure list 12.

Consider these as recursive procedures. Then, as described above, translation processing (object code generation) suitable for executing the recursive procedure is performed. On the other hand, regarding procedure proc 2 in source program 8.

Since the procedure name exists in the non-recursive procedure list 12, the translation unit 7 regards this as a non-recursive procedure. Then, as described above, static area allocation on the stack is performed, and corresponding translation processing (object code generation) is performed.

The object modules collected as described above are considered to have been subjected to optimization processing for non-recursive procedures.

〔Effect of the invention〕

As explained above, according to the present invention, in the translation process of a program written in a programming language that allows recursive procedure calls, non-recursive procedures are recognized at the time of translation and optimization processing is performed. This can improve the processing overhead of recursive calls and shorten the overall program execution time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle configuration of the present invention. FIG. 2 is an explanatory diagram of one embodiment. I is a processing device, 2 is a translation processing unit, 3 is a translation assisting unit, 4 is a temporary translation unit, 5 is a graph creation unit, 6 is a recognition unit, 7 is a translation unit, 8 is a source program 99 is an object module, 10 is a Call file table. 11 is a call structure graph, and 12 is a non-recursive procedure list.

Claims (1)

[Claims] In a program translation processing method having a translation unit (7) that translates a source program (8) written in a procedural programming language that allows recursive procedure calls, a temporary translation unit (4) that performs processing to extract the procedure name called by each procedure; and a graph creation unit that creates a call structure graph according to predetermined rules based on the processing results of the temporary translation unit (4). (5) and. a recognition unit (6) that recognizes a non-recursive procedure based on the call structure graph, the source program (8) in the translation unit (7);
When performing the translation process, by referring to the recognition result of the recognition unit (6), the non-recursive procedures in the source program (8) are optimized. A program translation processing method.