JPH0497424A - System for compressing initial value in load module - Google Patents

Abstract

PURPOSE:To suppress the increment of a load module(LM) and to efficiently store an initial value by providing this compressing system with an object module(OM) forming means, a linking means, and an LM executing means. CONSTITUTION:Respective intra-OM initial value control information having information for controlling respective initial values are included in respective OMs OM1 to OMn formed by the OM forming means 1 stored in a compiler. The linking means 2 links the OM1 formed by the means 1 with other OMs OM2 to OMn formed by the means 1 and forms an executable LM. The LM executing means 3 reads out the LM formed by the means 2 to an execution memory space and executes the read LM. Since processing can be attained only by repeatedly storing the initial value in the LM, the increment of the LM can be suppressed and the initial value can be efficiently stored.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an initial value compression method within a load module in compiling, linking and executing a program in a computer system.

[Conventional technology]

When an object module is generated by a compiler, it is necessary to store the initial values of the program inside it.

The memory space that the program indicated by the object module occupies during execution (hereinafter referred to as the execution memory space) is explicitly designated by the program and has an area where the initial value is determined (hereinafter referred to as the initialization area) and the initial value. Normally, there are alternately areas in which only areas are reserved without being defined (hereinafter referred to as non-initialized areas). For this reason, initial values corresponding to the initialization area are usually stored in the object module regardless of their location in the execution memory space, and each initial value indicates which part of the execution memory space the initial value represents. It was usual to add information (hereinafter referred to as initial value control information) and store it.

Furthermore, since the contents of the initialization area for arrays are often a repetition of a certain initial value, the initial value is a repetition type in which only one repetition is stored and the number of repetitions is included in the initial value control information. A method has also been used in which initial value control information is used to reduce the occupied size of the initial value within the object module.

Next, regarding the load module, if the format in the load module is such that it is necessary to store the initial value state expanded in memory in some format, there is one method to achieve this. A possible method would be to store the image expanded in memory as is on the load module.

However, since initial values are not necessarily specified for all areas that a program occupies on memory, in the case of the above initial value storage method, non-initialized areas are also stored in the load module. Therefore, the non-initialized area is usually filled with appropriate values and stored on the load module.

However, since the non-initialized area is originally an area for which no initial value is defined, if it occupies the area on the load module, it will lead to an unnecessary increase in the size of the load module.

Therefore, if there is a non-initialized area in the image expanded to the execution memory space, only the portion excluding the non-initialized area is stored on the load module at the starting position in the execution memory space of each initial value. There is a method for reducing the size of a load module by storing initial values together with control information such as size and size, and allocating each initial value to the real memory space when inputting to the execution memory space.

[Problem to be solved by the invention]

When using the conventional method of compressing the initial values in the load module as described above, the size of the load module is prevented from increasing due to uninitialized areas occupying the area in the load module. becomes possible.

However, if the same image is repeated multiple times, such as an initial value for an array, or if the initial value is compressed in the object module, it will be expanded and stored in the load module. If such an initialization area is very large, the size of the load module will increase.

[Means to solve the problem]

The present invention solves this problem of the prior art when the initial values in the object module generated at compile time are of a type that repeatedly initializes a specific area with the same image. object module generation means that has a function of storing initial value control information in the object module in a repeatable object module that requests repeated initialization with the same image of a specified area instead of all images; If initial value control information exists in the type object module,
A linking means having a function of generating initial value control information in a repetitive load module that requests repeated initialization of a specified area in the execution memory space with the same image and storing it in the load module, and executing the load module. and a load module execution means having a function of repeatedly initializing a designated area according to repetitive type load module initial value control information in the load module. This is solved by

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, an object module 0 generated by object module generation means 1 in the compiler
Each of M1 to OMn includes object module initial value control information (hereinafter referred to as OM initial value control information) having information for controlling the initial value in addition to the initial value.

FIG. 2 shows the initial value control information within the OM.

This OM initial value control information is divided into an OM offset part, an image size part, an offset part, and a repetition number part. Indicates location and size. Further, the offset part indicates the relative position from the beginning of the execution memory space occupied by the object module OM of the initialization area to be initialized by this OM internal initial value control information, and the repetition number part indicates the number of repetitions of the specified initial value. show. However, the number of repetitions is usually "0"
When it is "1" or more, it becomes the initial value control information in the repeating type OM.

FIG. 3 is a flowchart showing the initial value generation process 11. First, it is determined in GOI whether or not all initial values have been output, and the processes of GO1 to GO4 are repeated until all initial values have been output. In GO2, the initial value image is output onto the output object module 90M.

Next, in GO3, set the OM internal offset, image size, offset, and repetition count information in the OM initial value control information, and in Go4, set the initial value control information with the necessary information in GO3 to the object module OM. Appear. The above process is repeated until all initial values have been output.

The linking means 2 combines the OMI generated by the object module generating means 1 with the object modules OM2 to OM2-n generated elsewhere to generate an executable load module LM. First, in the object module input process 21, input OMI~n,
In link processing 22, external references between OMI and OMn are resolved. Next, in the initial value expansion process 23, OMI~M
After expanding the initial value of On to be equivalent to the layout in the execution memory space, delete the non-initialized area and load it together with the initial value control information in the load module (hereinafter referred to as the initial value control information in the LM). Output into module LM. Finally, the load module generation process 24 outputs process information such as the execution start address/required memory size number/memory protection area information required for the load module other than the initial value, thereby completing the load module LM.

FIG. 4 is a flowchart showing the process of the initial value expansion process 23, and FIG. 5 is a diagram showing the structure of the LM initial value control information generated in the initial value expansion process 23. This L
The intra-M initial value control information is divided into an intra-LM offset section, an image size section, an offset section, and a repetition number section, and the intra-LM offset section and image size section indicate the position within the LM of the initial value indicated by this initial value control information. and size. Further, the offset section indicates the position in the execution memory space to be initialized by this LM internal initial value control information, and the repetition number section indicates the number of times the specified initial value is repeated.

The outline of the initial value development process 23 will be explained below with reference to FIG. However, in this case, the OM initial value control information included in the human-powered OM is sorted in ascending order using the offset as a key, and it is assumed that multiple pieces of OM initial value control information do not initialize the same area. First, the LGI determines whether or not initial value processing has been completed for all input OMs, and LG2 and 3 perform initial value processing for 10M processing until initial value processing has been completed for all input OMs. After performing the conversion process, the process for LG4 to LG9 is repeated every 0M. Next, in LG2, set the address of the start position on the execution memory where the OM currently being processed is placed in ba, and
Set. Next, in LG4, all image sizes included in the OM to be processed are added. Next, in LG9, a value obtained by adding the image size to the offset is set to iX, and the processing for one piece of OM initial value control information is completed. The load module execution means 3 loads the load module LM generated by the link means 2 into the execution memory space and executes it. First, in the process information load process 31, the load module L
Reads process information such as execution start address/required memory size number/memory protection area information and initial value control information in LM in M, and then expands the initial value into the execution memory space in the initial value loading means 32 according to the information. After that, execution moves to the specified execution start address in the execution memory space.

FIG. 6 is a flowchart showing the initial value load processing 32. In LDI, it is determined whether the processing of all the LM initial value control information in the load module LM has been completed, and LD2 to LD7 are repeated until the processing of all the LM initial value control information is completed. In LD2 and LD3, the number of repetitions in the LM internal initial value control information is set in cnt, and the offset is set in pt. In LD4, the LM to be processed is stored in the area pointed to by pt in the execution memory space.
Set the initial value for the image size on the load module pointed to by the initial value control information.

Next, cnt is decreased in LD5, and the value of the image size is added to pt in LD6, so that pt points to the beginning of the next initialization area in case of repetitive initial value control information. Finally, it is determined in LD7 whether cnt is 0 or more, and if it is 0 or more, the process returns to LD4. With the above processing, initial value load processing 32
end.

[Effects of the Invention] As explained above, according to the present invention, even in a load module that includes initialization of an area such as repeating a certain initial value image sequence multiple times, Since it is only necessary to store the initial value in the load module, it is possible to suppress the increase in the number of load modules, and it is also possible to store the initial value efficiently.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of initial value control information in an object module,
3 is a flowchart showing a processing example of the initial value generation processing 11, FIG. 4 is a flowchart showing a processing example of the initial value expansion processing 23, FIG. 5 is a diagram showing the configuration of initial value control information in the load module, and FIG. FIG. 6 is a flowchart showing a processing example of the initial value load processing 32. 1... Object module generation means, 2... Linking means, 3... Load module execution means.

Claims (1)

[Claims] In the initial value compression method in a load module, where there are initial values in an object module generated at compile time that repeatedly initialize a specific area with the same image, object module generation means for storing in an object module initial value control information in a repeating type object module that requests a repeated initial value based on an image, and the initial value control information in a repeating type object module being present in an input object module at the time of linking. In this case, linking means generates initial value control information in a repetitive load module that requests repeated initialization of a specified area with the same image in the execution memory space and stores it in the load module, and a linking means that executes the load module. and load module execution means for repeatedly initializing a designated area according to repetitive initial value control information in the load module in the load module.