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Patent Searching and Data


Title:
HIGH-SPEED BACK TRACK SYSTEM
Document Type and Number:
Japanese Patent JPH01251138
Kind Code:
A
Abstract:

PURPOSE: To decrease restoring frequency and to carry out the prolog, etc., at a high speed by restoring only the save contents of a register whose contents are changed in accordance with the state of a changed flag means in a back track state.

CONSTITUTION: The unchanged contents of a subject register are saved to a choice point area only at the first change of the contents of said register. Then the save contents of a register where the change of contents is shown by a changed flag means (at fail) are restored into the original register for a back track where the changed flag means is added to each register to show the register (saved to the choice point area) whose contents are changed. The contents of all subject registers are saved and this fact is stored in the corresponding changed flag means at change of the register contents. Then it is possible to restore only the registers whose contents are changed via the changed flag means at back track.


Inventors:
SEGAWA KIYOSHI
SANO YOSHINOBU
Application Number:
JP7879388A
Publication Date:
October 06, 1989
Filing Date:
March 31, 1988
Export Citation:
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Assignee:
TOSHIBA CORP
International Classes:
G06F9/44; G06F17/30; (IPC1-7): G06F7/28; G06F9/44
Attorney, Agent or Firm:
Takehiko Suzue (2 outside)