Compiling device and method for performance speed-up of a program

A compiling method performed by a computer and comprising:

• when access to adjacent data is included in a loop of a source program, determining whether the loop of the source program can be vectorized;
• generating a vector load instruction to read an element required for computation from a memory to a vector register when the access to the adjacent data is included in the loop of the source program and the loop of the source program is vectorizable;
• generating a vector element shift instruction that generates vector data obtained by shifting an element read into the vector register;
• generating a vector computation instruction to execute a computation;
• generating a vector store instruction to write a computation result from the vector register to the memory;
• and
• executing the vector element shift instruction without reducing vector length, which provides efficient execution of the computation,
• wherein when a value of a subscript of an adjacent array element increases, the vector element shift instruction shifts data of a specified first vector register to the left by an amount of the increase in the value of the subscript of the adjacent array element and substitutes the data of the specified first vector register into a second vector register, and further combines data from a head element of a next vector register to a tail element by a same amount as the amount of the increase in the value of the subscript of the adjacent array element.

A non-transitory program recording medium storing a compiling program executable on a computer to perform processing comprising:

• determining whether vectorization of a loop of a source program is possible when an access to adjacent data is included in the loop of the source program;
• generating a vector load instruction to read an element required for computation from a memory to a vector register when the access to the adjacent data is included in the loop of the source program and the vectorization of the loop of the source program is possible;
• generating a vector element shift instruction that generates vector data obtained by shifting an element read into the vector register;
• generating a vector computation instruction to execute a computation;
• generating a vector store instruction to write a computation result from the vector register to the memory;
• and
• executing the vector element shift instruction without reducing vector length, which provides efficient execution of the computation,
• wherein when a value of a subscript of an adjacent array element increases, the vector element shift instruction shifts data of a specified first vector register to the left by an amount of the increase in the value of the subscript of the adjacent array element and substitutes the data of the specified first vector register into a second vector register, and further combines data from a head element of a next vector register to a tail element by a same amount as the amount of the increase in the value of the subscript of the adjacent array element.