Abstract: A method, computer system and computer program for optimizing the processing of a character string during execution of the program by using characteristic information that indicates a characteristic of the character string and is associated with the character string. The method includes the steps of determining, on the basis of a characteristic of a first character string and operation for the first character string, a characteristic information of at least one of the first character string and a second character string obtained as a result of the operation, and associating the characteristic information with the at least one character string.

Abstract: A method of converting a program code of a program running in multi-thread to a program code which causes fewer lock collisions. The method includes reading the program code into a memory and searching the program code for a first conditional statement making a branch to a path, which is in a synchronized block and has no side effect on the synchronized block; duplicating the path having no side effect to which the branch is made by the searched first conditional statement into the outside of the synchronized block; and adding a second conditional statement into the program code in response to the duplication, wherein the second conditional statement is a conditional statement making a branch to the duplicated path having no side effect. Also provided is a system and an article of manufacture which causes a computer to carry out the steps of the above method.

Abstract: A method, computer system, and computer readable article of manufacture for converting a first program code in a multi-threaded program into a second program code which causes less lock contention. A processing unit determines whether the first program code includes either a first class having a method call to a third class that operates while taking synchronization by locking, or a second class inheriting a parent class that operates while taking synchronization by locking. If the first class, then it is converted into a class with a method call to a concurrent operation executable class that is functionally equivalent and a shorter lock holding section. If the second class, then it is converted into a class with a method call to a concurrent operation executable class that is functionally equivalent to that of the parent class, and a shorter lock holding section.

Abstract: It is one object of the present invention to provide a program execution method for performing greater optimization. A program execution apparatus according to the present invention performs a transfer from an interpreter process to a compiled code process in the course of the execution of a method. At this time, if no problem occurs when a transfer point is moved to the top of a loop, the transfer point for code is so moved. And when a transfer point is located inside a loop, a point that post-dominates the top of the loop and the transfer point is copied to a position immediately preceding the loop. Then, information for generating recalculation code is provided for the transfer point, and a recalculation is performed.

Abstract: An object movement control system, an object movement control method, a server, and a computer program that can update the positional information of an object in a virtual space at high speed by appropriately distributing processing loads. Client control units obtain information about the position of a first object in a virtual space and information about movement of the first object and detect other objects that exist in a virtual region that contains the first object, which has been moved. The distances between objects that exist in a virtual region are calculated, and only when the number of objects the distances to which are shorter than a predetermined threshold exceeds a predetermined number, information about the objects is sent to a server. The server assigns a collision determination client that performs collision determination to each pair of objects selected from the objects.

Abstract: A compiler optimizing conversion of a character coding system for a character stored in a string variable in a target program to be optimized has a conversion instruction generation section which generates a conversion instruction to convert a character from a first character coding system to a second character coding system and to store the converted character in the string variable, the conversion instruction being generated before each of a plurality of procedures by which the character in the string variable written in the first character coding system is read out and is used in the second character coding system, and a conversion instruction removal section which removes each of conversion instructions generated by the conversion instruction generation section if a character in the second character coding system is stored in the string variable in each of the execution paths executed before the conversion instruction.

Abstract: A method for reducing memory size allocated by a string using Unicode, including converting a plurality of Unicode strings into a string class, and storing the string class representing the converted plurality of Unicode strings into memory. The Unicode strings are storable in a compressed format.

Abstract: The present invention improves efficiency in processing for outputting a character string. A system of the present invention firstly acquires an output program for sequentially executing a plurality of character string output instructions, and thereby for outputting a text in which a plurality of output character strings are combined. The system then converts the character code set of the character string constants, which is outputted by at least one of the character string output instructions, from a first code set for internal processing to a second code set for output, before the output program is executed. In addition, the system buffers the values of two or more character string variables to be outputted by two or more of the character string output instructions without converting the character code set from the first code set, during the execution of the output program.

Abstract: Provides a compiler which optimizes conversion of a character coding system for a character stored in a string variable in a target program to be optimized has a conversion instruction generation section which generates a conversion instruction to convert a character from a first character coding system to a second character coding system and to store the converted character in the string variable before each of a plurality of procedures by which the character in the string variable written in the first character coding system is read out and is used in the second character coding system, and a conversion instruction removal section which removes each of conversion instructions generated by the conversion instruction generation section if a character in the second character coding system is stored in the string variable in each of the execution paths executed before the conversion instruction.

Abstract: The present invention provides a method and a system for generating an exception handling instruction and for avoiding the execution of unnecessary instructions. More particularly, an internal opcode in a compiler is read and one internal opcode is obtained. Whether or not the obtained internal opcode is an instruction for which exception checking is required is determined. If exception checking is required for the opcode, an exception checking instruction having a sequence of bits that are uniquely determined must be generated in accordance with the type of exception, without generating an instruction for substituting into a register a label indicating the type of exception. Then, a processor instruction is generated corresponding to the obtained internal opcode. The above processing is repeated for the remaining internal opcode, and an exception handling instruction is generated.

Abstract: To increase the speed of program execution by decomposing a loop onto a plurality of processors and executing them in parallel. First, a loop in a source program is located which is to be executed in parallel. This loop is then analyzed for data dependence. The result of the analysis is used for calculating data dependence vectors. Then all areas of the index executed in the loop are decomposed and assigned to a number of processors. Further, it is determined whether data needs to be transferred between processors. Based on the array index space, communication vectors are calculated. Data dependence vectors and communication vectors are ANDed to calculate communication dependence vectors. Then, the manner of communication of operands and loop execution are determined based on the values of communication dependence vectors.

Abstract: A method for communication between processors in a parallel computer, particularly a method in which a past communication history is used to omit the calculation of the communication pattern between processors, whereby the communication between processors is carried out at high speed.