JPS62138967A - Data converting and processing system - Google Patents

Abstract

PURPOSE:To decrease the possibility to generate a malfunction by saving the contents of a register to a memory on the way to convert an arithmetic operation formula tree to an arithmetic operation instruction without forecasting whether or not the arithmetic operation result accommodated to a register is saved to a memory. CONSTITUTION:An inputted arithmetic operation formula tree, in a common arithmetic operation item overlapping device 1, traces in the back end formula sequence (the sequence of f, g, d, h and b) from arithmetic item codes f-k to operator nodes a-e, registers to an arithmetic operation item memory device 2 and the common arithmetic operation item overlapping device 1 investigates the registered arithmetic operation item and at the time of the same arithmetic operation item, overlapping is executed. A register control device 4, when an arithmetic operation formula converting device 3 converts the arithmetic operation item to the arithmetic operation instruction, executes the assignment of the register needed to hold the arithmetic operation result, and when the register to be assigned is already used to hold other arithmetic operation result, the contents are saved to the memory and can be used.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a data conversion processing method in a data conversion device, and is for converting an arithmetic expression tree into an arithmetic operation instruction string for an arithmetic operation unit. Concerning the conversion processing method.

(Prior art) Conventionally, this type of data conversion processing method predicts whether or not the arithmetic operation result stored in a register needs to be saved to memory before converting it to an arithmetic operation instruction. I went there after that. Also, the common subexpressions were not superimposed.

(Problems to be Solved by the Invention) In the conventional data conversion processing method described above, it is necessary to create a prediction for each arithmetic unit as to whether or not the arithmetic operation result stored in the register will be saved to memory. was not performed accurately, causing malfunctions. Furthermore, since the common subexpressions are not superimposed, the converted arithmetic operation instruction string contains redundant arithmetic operation instructions, resulting in redundancy.

(Means for Solving the Problem) The data conversion processing method of the present invention does not predict whether or not the arithmetic operation result stored in a register will be saved to memory, but instead performs an arithmetic operation on an arithmetic operation expression tree. During conversion to an instruction, if the register for storing the operation result is already in use for storing the previous arithmetic operation result, by saving the arithmetic operation result stored in the register to memory,
Duplicate arithmetic operation instructions in the converted arithmetic operation instruction sequence are deleted by reducing the possibility of malfunctions and by resizing common subexpressions.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an embodiment of an apparatus embodying the data conversion processing method of the present invention. Reference numeral 1 denotes a common arithmetic operation term superposition device for searching for a common sub-expression from among the input n arithmetic wave expressions and superimposing the common sub-expressions. 2 is an arithmetic operand storage device for holding common subexpressions used in the common arithmetic operand superposition device 1; 3 is an arithmetic expression conversion device for converting an arithmetic expression tree into an arithmetic operation instruction string for an arithmetic operation unit. 4 allocates registers required to hold arithmetic operation results when the arithmetic operation expression conversion device 3 converts an arithmetic operation term into an arithmetic operation instruction, and the register to be allocated has already been used for another arithmetic operation result. This is a register management device that saves the contents of a register that is already in use to memory and makes it usable when the register is being used to hold a register. 5, as a result of the arithmetic operation term being converted into an arithmetic operation instruction by the arithmetic operation expression conversion device 3, the arithmetic operation term is rewritten into the register where the arithmetic operation result is held, or the register management device 4 rewrites the register in use. This is an arithmetic operation term rewriting device for rewriting an arithmetic operation term to a memory in which the arithmetic operation result is held as a result of saving the contents to the memory.

FIG. 2 is a diagram showing an example of an arithmetic expression tree that is input data to the data conversion processing device of the present invention. Each arithmetic operation term (a-k) of the arithmetic operation expression tree is placed on a random access memory and is related by an address value of .about.[stock]. Among the arithmetic operands (a-k) in Figure 2, a-e are called operator nodes, and f-k are called operator mates,
The data structure of each node is shown in FIGS. 3 and 4. The operator node in FIG. 3 holds an address for pointing to an operand.

The operand node in FIG. 4 holds an address value pointing to the operand or a value indicating the register type.

FIG. 5 shows an arithmetic expression tree obtained by superimposing common subexpressions on the arithmetic expression tree of FIG. 2.

Next, the operation in this embodiment will be explained. The arithmetic expression tree input to this data conversion processing device is processed in the common arithmetic operand superposition device 1 in the order of postfix expressions (f, g, d, h, b in Fig. 2) from the operand node to the operator node. ) and register it in the arithmetic operation term storage device 2. The common arithmetic operation term superimposition device 1 examines the arithmetic operation terms already registered in the arithmetic operation term storage device 2, and performs superposition if there are the same arithmetic operation terms. The superimposed common subexpressions will be pointed to by the same address value from multiple operator nodes. The arithmetic operation large tree on which all the superpositions have been performed is the arithmetic expression conversion device 3.
Conversion into arithmetic operation instructions that are converted into arithmetic operation instructions is performed by successively converting into arithmetic operation instructions corresponding to each operator node in the order of postfix expressions. In the conversion to an arithmetic operation instruction, registers necessary for storing the operation result are received from the register management device 4 and used. The operator node converted into an arithmetic operation instruction is rewritten by the arithmetic operation item rewriting device 5 into an operation item node that holds the register received from the register management device 4.

(Effects of the Invention) As explained above, the data conversion processing method of the present invention does not predict whether or not the arithmetic operation result stored in the register will be saved to memory, but converts the arithmetic expression tree into an arithmetic instruction. During the process, when the register for storing the result of the operation n is already in use for storing the result of the previous arithmetic operation,
By saving the arithmetic operation results stored in the registers to memory, the possibility of malfunctions is reduced, and by overlapping common subexpressions, duplicate arithmetic operation instructions in the converted arithmetic operation instruction string are eliminated. There is an effect that can be deleted.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of a device embodying the data conversion processing method of the present invention, Fig. 2 is a diagram showing an example of a large arithmetic operation tree, and Fig. 3 is an example of the data structure of an operator node. FIG. 4 is a diagram showing an example of the data structure of an operand node, and FIG. 5 is a diagram showing an example of the result of superimposing common subexpressions. In the figure, 109. Common arithmetic operand superposition device, 2... Arithmetic operand storage device, 3... Arithmetic expression conversion device, 4... Register management device, 5... Arithmetic fl'J'r operand rewriting device , a-k・
・・Arithmetic operator, ■〜[Stock]・6. Each indicates an address value.

Claims (1)

[Claims] An arithmetic operation expression expressed in a tree structure (arithmetic operation expression tree) is used as input data, and an arithmetic operation instruction sequence to an arithmetic operation unit having one or more high-speed registers and memory for primary storage is output data. In the data conversion processing method, by overlapping a common subexpression that is a duplicate arithmetic operation subexpression that appears in an arithmetic operation expression with the same arithmetic operation subexpression,
All isomorphic arithmetic subexpressions of the arithmetic operation expression tree that are input data are superimposed, and the arithmetic operation results are converted into arithmetic operation instructions that store the arithmetic operation results in registers while tracing the arithmetic operation terms from the bottom to the top of the arithmetic operation expression tree. In conversion to an arithmetic operation instruction, if the register storing the arithmetic operation result is already in use for storing the arithmetic operation result in a previous arithmetic operation instruction, the contents of the register holding the previous arithmetic operation result are A data conversion processing method characterized by converting an arithmetic expression tree into an arithmetic operation instruction string by outputting an instruction to save to a memory and then converting it into an arithmetic operation instruction that stores an arithmetic operation result in the register.