US 6,324,641 B1 · Program executing apparatus and program converting method

Abstract

To simplify the process relative to an instruction array including an instruction for a process with flag handling executed by a compiler when converting a high-level program into in a format executable by a program executing apparatus, a number of operating circuits, namely, an ALU circuit and a AND operation circuit, are provided to operate in parallel to handle different flags in a flag group based on the results of respective operations. A value comparison instruction and a bit test instruction are converted into common operation process instructions, and branch instructions, dependent on the result of the execution of the operation process instructions, are prepared so as to detect different flag patterns. The common use of an operation instruction for a number of flag-handling instructions simplifies a compiler judgement.

Claims5

Dependent claims

A program executing apparatus, comprising:

a fetching section for sequentially fetching instructions;
a decoding section for decoding the instructions fetched;
a flag holding section for holding a number of flags corresponding to different states;
and
an operation executing section for executing the decoded instructions, having one operation circuit for executing an operation corresponding to an instruction decoded by said decoding section and changing at least one flag, and at least one operation circuit for executing a predetermined operation independently from said decoded instruction and changing at least one flag,
wherein the operation circuits execute a number of operations in parallel, each accompanying a process for changing a flag by using inputted operands commonly in the predetermined operation to handle the flags allotted for each operation according to results of the operations.

3 more elements

A program converting method for converting a program including a high-level instruction described in a high-level programming language, into a number of low-level instructions corresponding to a machine language executable by a program executing apparatus, wherein

the program executing apparatus comprises:
fetching section for sequentially fetching instructions,
decoding section for decoding the instructions fetched,
flag holding section for holding a number of flags corresponding to different states, and
operation executing section for executing the instructions, which execute a number of predetermined operations each accompanying a process for changing a flag, by using inputted operands commonly in the predetermined operations, to handle the flags allotted for each predetermined operation, according to results of the predetermined operations,
the operation executing section including a number of operation circuits for executing the predetermined operations in parallel by using the operands commonly in the predetermined operations, such that each operation circuit executes each the predetermined operation to handle the flag allotted to the predetermined operation according to the result of the predetermined operation,
and wherein
the program converting method converts a high-level flag-using instruction into the number of low-level instructions including an operation process instruction and a flag dependent process instruction,
the high-level flag-using instruction for executing the operation to set the flags allotted to the predetermined operation according to the result of the predetermined operation so that flag dependent process is executed based on the flag,
the operation process instruction for executing the predetermined operations by the operation executing section using the inputted operands, to set the flags according to results of the predetermined operations,
the flag dependent process instruction for executing the flag dependent process based on the flag set by the operation circuit which executed the predetermined operation instructed by the high-level flag-using instruction.

8 more elements

Dependencies are inferred from the claim text.

Program executing apparatus and program converting method

Life of this patent

Program executing apparatus and program converting method

Life of this patent

Abstract

Claims5