JPS60160444A - List processing method - Google Patents

Abstract

PURPOSE:To shorten the processing time when the elements of the same list are read again by storing previously all elements on the route led to the element to which an access is once given as well as the pointer to a cell set outside said route to an associative memory. CONSTITUTION:For a list shown by (T47 years old, man), etc., a binary tree is used as shown in the figure. For instance, an element (q), i.e., ''36 years old'' can be expressed in a digit train ''1010''. A key of ''1010'' is used to give an access to an associative memory for the element (q). When no data corresponding to said key is registered, the cells are traced in the order of (a) (b) (g) (h) (q) as shown in the figure on a main memory in the same way as conventional. The elements which received accesses with tracing cells on the main memory are stored to the associative memory by using a symbol pattern showing the route of the binary three as a key. In this tracing case, an element p ''S'' which obtained by reversing the tracing route is also stored to the associative memory at a time with a pattern ''100'' used as a key.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a list processing method for list-structured data.

[Background of the invention]

The structure of the list is shown, for example, in "List Processing and Architecture", Information Processing Society of Japan, Vol. 23, No. 8. The list in Figure 1 consists of name, 9 years of age, and gender.
It can be represented by a structure as shown in FIG. If the tore is expressed as a binary tree, it will look like Figure 3. Now, assume that the third element among the second elements in the list of FIG. 1, ie, "man" is to be accessed. At this time, in the conventional method, the cells placed on the memory are sequentially transferred to a and b.

Follow g+J' to reach "man". For this reason, 5 cells
It has the disadvantage that it has to be read out twice, and it takes time to read out the elements.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a list processing method for accessing list elements at high speed in order to solve the above-mentioned drawbacks.

[Summary of the invention]

In order to achieve the above objective, it is necessary to directly access the target element and significantly reduce the time required for access. Normal memory is accessed by address, so cells must be traced, but in the processing parts of computers that require particularly high speed, it is possible to directly access the desired element by numbers or character strings. Associative memory is used.

When processing lists in symbolic processing, etc., the same list is often manipulated repeatedly, so when you first manipulate the list and access an element by tracing multiple cells, When storing the elements of all cells in associative memory and accessing the elements on the route from next time onwards,
This is characterized by direct access from associative memory.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

FIG. 4 is a configuration diagram showing an embodiment of a computer having an associative memory. In symbolic processing, a program written in a language such as Lisp is executed by the computer shown in FIG. The list shown in FIG. 1 is stored on the main memory (MS) 1 shown in FIG. 4 using the structure shown in FIG. 2.

For example, suppose that the list in FIG. 1 is manipulated to read out the second element q among the second elements. The list in Figure 1 is represented by the binary tree in Figure 3, with 1'' when proceeding to the right from a node in the binary tree, and @0'' when proceeding to the left.
This element q1, that is, "36o" is expressed as "11#→
10#→11#→““0”” (abbreviated as @1010”). Therefore, this element q “3
6o" is an associative memo as shown in Figure 5 using the "1010" pattern as the key! J(AS)2.

When the second element q in the second element of the list in Figure 1 is accessed using the key 1010'' in the associative memory, and data corresponding to this key is not registered. As in the conventional method, main memory (MS) 1
The cells in Figure 2 stored above are a −+ b −+
g −+ h −) q to access the target element q. In this way, when a certain element is accessed for the first time by sequentially tracing the cells in the main memory, this element is written into the associative memory using the symbol pattern indicating the path of the binary tree shown in FIG. 3 as a key. (For element q "36o", '101
0" is used as a key.) During this tracing, the element prsJ that can be traced by going in the opposite direction from the cell on the route is also written with the number string 20"10.
0'' as a key and stored in the associative memory at the same time.

After that, when the list in FIG. 1 is operated again to read out the first element p among the second elements, in the conventional method, the cells in the main memory (MS) 1 must be traced again. On the other hand, as shown in Mizuko in FIG. 5, the element prSJ can be immediately retrieved as 29 from the associative memory using "100" as a key. It goes without saying that the element q "36o" can be read out from the associative memory.

When reading out the second element q "36o" in the second element of the list in Figure 1, as shown in Figure 6,
Pointers to nodes C and i that have deviated from the route are also stored in the associative memory, eliminating the need to trace the same part of the route when accessing elements that are not on the route, thereby reducing read time. can.

Now, for example, a case will be shown in which the element 5rKJ corresponding to the number string 3o"1100" is accessed. Number string 30 ”1
100', "1", "101", '100'.

A pointer 39 to cell C, which corresponds to #1# with the longest match when compared from the left with "1010", is output from the content addressable memory (AS) 2. Obtaining this, cell C
From there, element rKJ can be reached by tracing 0''→''0''.

〔Effect of the invention〕

According to the present invention, all elements on the route to the element once accessed and pointers to cells that have deviated from the route are stored in the associative memory, so that when rereading the elements of the same list, the processing This has the effect of shortening time. For example, if you read the final list of a list consisting of n elements, store all elements in an associative memory, and then read all elements, the total processing time will be the time it takes to read one cell (2n- 1) It is shortened to t. the

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of a list, Figure 2 is a diagram showing the list structure of Figure 1, Figure 3 is a diagram of the list in Figure 2 expressed in two launches, and Figure 4 is an associative memory. FIG. 5 is a configuration diagram showing an example of a computer having the computer. FIG. 6 is a diagram for explaining the relationship between keys and output results in the associative memory. B--A...Cell, mzu...Element, N engineering L...
・Empty list, 1... Main memory (MS), 2... Associative memo! J (As), 3... Arithmetic processing unit (BPu), 4
... Channel control (CI-I C), ... Channel (CH), 6 ... Input/output device ft (Ilo), 7 ...
・Console Service Grosse Figure 1 (41 year old male) (536 year old male) (Kl'i year old ￥
Figure 53 Continuation of page 1 @ Inventor Masaaki Iwasaki @ Inventor Imon Tokuan, Hitachi, Ltd. Central Research Laboratory, 1-28 Hata, Higashi-Koigakubo, Kokubunji City, Hitachi, Ltd., Hitachi, Ltd.

Claims (1)

[Claims] 1.2 In a list processing method in which elements of a list are read out using a symbol string representing a branching structure on a launch, when an element to be included in a list is accessed for the first time, all elements on the path leading to the element are stored in an associative memory, and the list is When reading an element, the symbol string representing the branching structure on the binary tree leading to the element is compared with the branching structure on the binary tree for the element already stored in the associative memory, and first the unmatched A list processing method characterized by starting traversal of a list from a viewed node.