JP2005293080A - Information processing apparatus, program processing method, and compile processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for quickly executing a loop vector operation indicated by a loop control statement using an inequality operator in a loop continuation conditional expression.
An information processing apparatus (100) includes compile processing means (10) for generating a target program (30) including a vector instruction by compile processing for a source program (20). The compile processing means detects a loop control statement (6-1) having a continuation conditional expression in which a control variable and a loop invariant closing price are related by an inequality operator from the input source program ( 11) and a transformation processing unit (12) that transforms the detected loop control statement into a plurality of loop control statements for executing a loop that is equivalent to the loop control statement and that is based on the closing price. Have
[Selection] Figure 1

Description

  The present invention relates to a compile process for generating a target program including a vector instruction from a source program described in a programming language such as C language or C ++ language, and particularly includes a loop control statement in which the number of repetitions is not specified. The present invention relates to a technique for performing the compile processing on a source program.

  Conventionally, when compiling a source program, for example, as shown in equation 5-1, FIG. 5, for loop control statements in which the number of iterations is specified, a vector instruction is applied to improve the efficiency of the arithmetic processing. It is known to plan. The expression 5-1 shown in the figure is a C for sentence shown as an example of a loop control sentence, and the number of loop iterations is defined by the continuation conditional expression 5a in the sentence.

  By the way, according to the loop control statement like the expression 6-1 in FIG. 6, it is considered that the same result as the calculation result according to the expression 5-1 is obtained. However, the expression 6-1 shown in FIG. Since the inequality operator “! =” Is used in the expression 6a, the algorithm involves jumping out of the loop.

Since the loop control statement as shown in FIG. 6 has an unknown number of repetitions, if it is vectorized, there is a high possibility that the arithmetic processing will be prolonged or fall into an infinite loop. Therefore, in general, this type of loop control statement is set in advance on the compiler side so as not to be vectorized. For example, if the methods described in Patent Documents 1 and 2 described later are used, the compiling process includes mask calculation and post-loop operation By adding the above process, it is possible to perform an appropriate vector operation even for a loop control statement whose number of repetitions is unknown as described above.
Japanese Patent Laid-Open No. 08-272777 Japanese Patent Laid-Open No. 11-250035

  However, when the methods of Patent Documents 1 and 2 described above are used, additional processing such as mask calculation and post-loop processing is required, which disadvantageously increases the program execution time.

  The present invention has been made in view of the above problems, and is an information processing apparatus that can quickly execute an operation content indicated by a loop control statement in which an inequality operator is used in a continuation conditional expression along a vector instruction, and Another object of the present invention is to provide a program processing method and a compile processing program for the apparatus.

  An information processing apparatus according to the present invention includes compile processing means for generating a target program including a vector instruction by compile processing for a source program, and the compile processing means receives control variables and loop invariants from the input source program. A detection processing unit for detecting a loop control statement having a continuation conditional expression associated with an unequal operator and a loop control statement detected by the detection processing unit is equivalent to the loop control statement. And a transformation processing unit that transforms into a plurality of loop control statements for executing a loop based on the closing price.

  According to the program processing method of the present invention, when an information processing apparatus that generates a target program including a vector instruction by compiling a source program receives a source program, a control variable and a loop-invariant closing price are obtained from the source program. A loop control statement having a continuation conditional expression related by an unequal operator is detected, and the detected loop control statement is equivalent to the loop control statement, and each executes a loop based on the closing price. It is a method of transforming into a plurality of loop control statements.

  The compile processing program according to the present invention is a compile processing program for causing a computer to execute a compile processing step for generating a target program including a vector instruction by compile processing for a source program, and when the source program is input, the compile processing program Prior to the step, a detection processing step of detecting a loop control statement having a continuation conditional expression in which a control variable and a loop invariant closing price are related by an inequality operator from the input source program, and the detection processing step Causing the computer to execute a transformation processing step that transforms the loop control statement detected in step 1 into a plurality of loop control statements that are equivalent to the loop control statement and that each execute a loop based on the closing price. .

  According to the present invention, since the loop control statement using the inequality operator in the continuation conditional expression is transformed into an equivalent loop control statement based on the closing price, the vector instruction generated by the compilation process is simplified. Can be This makes it possible to execute loop vector operations at high speed.

[Example]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an information processing apparatus according to an embodiment of the present invention. The information processing apparatus 100 according to the embodiment includes a compiler 10 corresponding to the compile processing unit according to the present invention. The compiler 10 is a compile processing program that causes the information processing apparatus 100 to generate a target program 30 including a vector instruction by compile processing for the source program 20 described in C language or C ++ language.

  The compiler 10 includes a loop end condition detection unit 11 that functions as a detection processing unit in the information processing apparatus of the present invention, and a loop deformation unit 12 that functions as a deformation processing unit. The loop end condition detection unit 11 receives from the source program 20 input to the compiler 10 a loop control statement having a continuation conditional expression in which a control variable and a loop invariant end value are associated by an inequality operator “! =”. Is detected. The loop transformation unit 12 transforms the loop control statement detected by the loop end condition detection unit 11 into a plurality of loop control statements that are equivalent to the loop control statement and that each execute a loop based on the closing price. To do.

  The compile processing procedure of the information processing apparatus 100 will be described along the flowchart shown in FIG. Here, for the sake of explanation, the source program 20 to be processed includes the for sentence of the expression 6-1 shown in FIG. 6, and “(initial value) <(final value)” and “(incremental value)” are also included. It is assumed that “> 0” and that “(final value)” is a loop invariant operand whose value does not change during the loop operation.

  First, when the source program 20 is input to the compiler 10 (step S1), the loop end condition detection unit 11 detects the expression 6-1 in FIG. 6 as a loop control statement corresponding to the detection condition described above (step S1). S2). The for-statement of the expression 6-1 has, as its continuation condition expression 6a, the relationship between the control variable “i” and the loop-invariant operand “(closing price)” by the inequality operator “! =”. It is defined. Here, the value of the control variable “i” is controlled to sequentially increase at intervals of “(initial value)” to “(increment value)” except for “(final value)”.

  The loop transformation unit 12 converts the equation 6-1 detected by the loop end condition detection unit 11 into a loop control statement equivalent to this (step S3). FIG. 3 shows a conversion result by the loop deforming unit 12. The illustrated expression 3-1 is a for statement in which “i <(final value)” using a magnitude comparison operator is set as the continuation conditional expression 3a, and the other expression 3-2 is “(initial value) ) ”Is a null value and“ i! = (Close price) ”is set as the continuation conditional expression 3b.

  3 is added to the loop control statement after conversion shown in FIG. 3 by adding the above assumptions “(initial value) <(final value)” and “(increment value)> 0”. The transition from “(initial value)” to “(close price)” is controlled with respect to the transition of the value given to, and the other expression 3-2 does not include “(close price)”. Control the gradual increase. That is, the combination of Formula 3-1 and Formula 3-2 is equivalent to dividing the range of values that can be taken by the control variable “i” of Formula 6-1 before conversion, with “(final value)” as a base point. To do. Therefore, the expression 6-1 before conversion is equivalent to the combination of expression 3-1 and expression 3-2 after conversion.

  The loop control statement of FIG. 3 converted by the loop deforming unit 12 is converted into a vector instruction by a process similar to that of a conventional compiler capable of vector processing (step S4), along with other instruction sequences compiled and processed. The program 30 is output (step S5).

  In the loop control statement after conversion shown in FIG. 3, the expression 3-2 responsible for the gradual increase after “(final price)” uses “! =” In the continuation conditional expression 3b, so that it is infinite. Problems such as the occurrence of loops and prolonged processing are likely to occur. Therefore, it is desirable to delete the expression 3-2 before vectorization or to the compiler 10 in advance so that the calculation is not executed even if it is vectorized, as in the prior art.

  According to the embodiment described above, prior to compiling the source program 20, a loop control statement using “! =” As a continuation conditional expression is replaced with an equivalent loop using a magnitude comparison operator such as “<”. Since it is converted into a control statement, the vector instruction sequence generated by the compilation process can be simplified. This makes it possible to execute vector operations at high speed.

  The loop control statement shown in FIG. 3 described in the above embodiment assumes that the value of the control variable “i” is gradually increased from “(initial value)” to “(final value)”. Although one set is modified, in implementing the present invention, a general-purpose loop control statement that does not depend on such a premise can be set.

  FIG. 4 shows the result of converting equation 6-1 into a general-purpose one by the loop transformation unit 12, and the algorithm generates the above-described equivalent loop control statement according to the increase / decrease condition of “i”. Therefore, a judgment process is performed. In FIG. 4, equation 4-1 is the same as equations 3-1 and 3-2 in FIG. That is, the equation 4-1 is a loop control applied when the operands of the equation 6-1 are “(initial value) <(final value)” and “(increment value)> 0” described in the above embodiment. It is a sentence.

  Further, in the expression 4-2, when the operands of the expression 6-1 are “(initial value)> (final value)” and “(increment value) <0”, that is, the value of the control variable “i” is “(initial This is a loop control statement that is applied when the value is gradually decreased from “value)” to “(close price)”.

  The expression 4-3 is, for example, “(initial value) = (final value)” or “(increment value) = 0” or “(initial value) <(final value)” and “(increment value) <0”. Or, when the loop is not substantially formed as in “(initial value)> (final value)” and “(increment value)> 0”, the value of the control variable “i” does not change, and the vectorization Since there is no need, the loop control statement has the shape of 6-1. The expression 4-3 is also applied to an infinite loop unless there is an explicit jump out of the loop.

  As described above, by using a general-purpose loop control statement as shown in FIG. 4, the compiler 10 does not grasp the operand contents of the loop control statement detected by the loop end condition detection unit 11 in advance. It is possible to generate a vector instruction similar to that generated by the embodiment described above.

  In the above embodiment, the for statement is used as the loop control statement according to the present invention. However, the for statement is not limited to the for statement, and can be applied to a loop using a while statement or a goto statement, for example. In addition, when a C ++ language STL (Standard Template Library) is used, “! =” Is used as a loop continuation conditional expression as is conventionally known, but the present invention is a C ++ language source program. Among them, it is suitable for an algorithm including an algorithm for executing continuous access to a memory such as an STL vector or valarray.

It is a block diagram which shows the structure of the information processing apparatus of the Example by this invention. It is a flowchart which shows the operation | movement procedure of an Example. It is explanatory drawing for demonstrating the conversion process step of an Example. It is explanatory drawing for demonstrating the conversion process step of another Example. It is explanatory drawing for demonstrating a general loop control sentence (the 1). It is explanatory drawing for demonstrating a general loop control sentence (the 2).

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Information processing apparatus 10 Compiler 11 Loop end condition detection part 12 Loop transformation part 20 Source program 30 Target program

Claims (9)

Compiling processing means for generating a target program including vector instructions by compiling processing for a source program,
The compile processing means includes
A detection processing unit that detects, from the input source program, a loop control statement having a continuation conditional expression in which a control variable and a loop invariant closing price are related by an inequality operator;
A transformation processing unit that transforms the loop control statement detected by the detection processing unit into a plurality of loop control statements that are equivalent to the loop control statement and that each execute a loop based on the closing price. An information processing apparatus characterized by that.   The transformation processing unit includes a first loop control statement having a continuation conditional expression in which the control variable and the closing value are related by a magnitude comparison operator, an initial value of the control variable is a null value, and the control variable The information processing apparatus according to claim 1, further comprising: a second loop control statement having a continuation conditional expression in which the closing price and the closing price are related by an unequal operator.   The information processing apparatus according to claim 2, wherein the deformation processing unit generates the first loop control statement and the second loop control statement corresponding to the increase / decrease condition of the control variable. An information processing apparatus that generates a target program including vector instructions by compiling a source program,
When a source program is input, a loop control statement having a continuation conditional expression in which a control variable and a loop invariant closing price are related by an inequality operator is detected from the source program, and the detected loop control statement is A program processing method, wherein the program processing method is transformed into a plurality of loop control statements for executing a loop that is equivalent to the loop control statement and each has a base point based on the closing price.   When the information processing apparatus converts the detected loop control statement, a first loop control statement having a continuation conditional expression in which the control variable and the closing price are related by a magnitude comparison operator, and the control variable 5. The second loop control statement having a continuation conditional expression in which an initial value is a null value and the control variable and the closing value are related by an unequal operator is generated. Program processing method.   6. The program processing method according to claim 5, wherein the information processing apparatus generates the first loop control statement and the second loop control statement corresponding to the increase / decrease condition of the control variable. A compile processing program for causing a computer to execute a compile processing step for generating a target program including a vector instruction by compile processing for a source program,
When a source program is input, prior to the compilation step,
A detection processing step of detecting a loop control statement having a continuation conditional expression in which a control variable and a loop invariant closing price are related by an inequality operator from the input source program;
A transformation processing step for transforming the loop control statement detected in the detection processing step into a plurality of loop control statements for executing a loop that is equivalent to the loop control statement and each of which is based on the closing price. A compile processing program to be executed by a computer.   In the conversion processing step, a first loop control statement having a continuation conditional expression in which the control variable and the closing value are related by a magnitude comparison operator, an initial value of the control variable is a null value, and the control variable 8. The compile processing program according to claim 7, wherein the computer is caused to generate a second loop control statement having a continuation conditional expression in which a continuity expression is associated with an inequality operator. 9. The compilation according to claim 8, wherein in the conversion processing step, the computer is caused to generate the first loop control statement and the second loop control statement corresponding to the increase / decrease condition of the control variable. Processing program.

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