Fujitsu Corporation

KohIchiro Hotta

Yutaka Igarashi

Masakazu Hayashi

Manabu Matsuyama

Masatoshi Haraguchi

Masanori Kira

Masaaki Takiuchi

A compiling system includes a first unit for converting a source program into an intermediate text formed of intermediate codes, each of the intermediate codes having a portion used to explicitly indicate information regarding a state of computer hardware, the computer hardware being operated in accordance with a machine language program, and a second unit for generating a machine language program using the intermediate codes of the intermediate text. In addition, a compiling system includes a first unit for converting a source program into an intermediate text formed of intermediate codes, each of the intermediate codes having a portion used to define a plurality of values, and a second unit for generating a machine language program using the intermediate codes of the intermediate text.

Compiling system using intermediate codes to store a plurality of values

In order to generate optimum codes for array descriptions having a new language specification, an optimization control apparatus or method for array description executes a function of determining a scope of executing optimization for the array descriptions on the basis of an optimization level determined in advance, the dimension number of an array of the array descriptions, and the array number of each dimension; a function of extracting information representing the respective forms of the array descriptions within the scope of executing the optimization; a function of detecting a common expression for each array description and recognizing information common to each array description; and a function of executing a loop merge determination process as to whether or not a loop merge for converting each array description to an optimum loop is to be carried out, for each array description whose form is defined during the generation of the optimum codes.

Optimization control apparatus and optimization control method for array

When a flow graph is created for a program including a complex if statement, the respective branch conditions in the complex if statement are separated and the flow graph designating the control flow corresponding to the logical value of respective branch conditions are created. Next, to perform the branch probability determining/allocating process, in the above flow graph, the value corresponding to the number of executions of respective paths is calculated so that the whole branch probability of the complex if statement designated by the optimization designating statement and the branch probability of respective branch conditions is assigned to the path corresponding to respective branch conditions.

Method of performing a compilation process for determining a branch

An optimizing compiler has a function of determining whether the result of a statement to be executed precedent to a conditional branch statement is not referred to by one destination of the conditional branch statement. If the conditional branch statement is not influenced by the execution result of the precedent statement, the conditional branch statement is shifted in front of the precedent statement, to suppress the execution of the unnecessary statement. Therefore, the optimizing compiler shifts/copies conditional branch statements, to shorten the execution time of an object program.

Optimizing compiler for shortening execution time of object program

A compiling apparatus has a front end for providing intermediate representations according to a source program; an optimizing unit for optimizing the intermediate representations; an intermediate representation changing unit for changing the optimized intermediate representations; and a code output unit for providing code according to the lastly obtained intermediate representations. The compiling apparatus further has an optimizing structure determination unit for determining the number of repetitions of an optimization phase achieved by the optimizing unit and intermediate representation changing unit and selecting optimization functions carried out in each of the optimization phases. The intermediate representations are changed and optimized in each optimization phase according to the determination by the optimizing structure determination unit.

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Kawasaki, Japan

KohIchiro Hotta