05142631 is referenced by 25 patents and cites 13 patents.

A method is provided for preprocessing multiple instructions prior to execution of such instructions in a digital computer having an instruction decoder, an instruction execution unit, and multiple general purpose registers which are read to produce memory addresses during the preprocessing. The method comprises: (1) avoiding the preprocessing of a current instruction to read a general purpose register to produce a memory address prior to the modification of the contents of that register by a preceding instruction by (a) generating a composite write mask having a bit set for each general purpose register whose contents are to be modified by at least one of a plurality of decoded by not-yet-executed instructions preceding the current instruction, and (b) stalling the preprocessing of the current instruction when a general purpose register to be read by the current instruction is a register having a bit set in the write mask, and/or (2) avoiding the preprocessing of a current instruction which modifies the contents of a general purpose register that is to be read by a preceding instruction by (a) generating a composite read mask having a bit set for each general purpose register to be read by at least one of a plurality of decoded but not-yet-executed instructions preceding the current instruction, and (b) stalling the preprocessing of the current instruction when a general purpose register whose contents are to be modified by the current instruction is a register having a bit set in the read mask.

Title
System for queuing individual read or write mask and generating respective composite mask for controlling access to general purpose register
Application Number
7/306773
Publication Number
5142631
Application Date
February 3, 1989
Publication Date
August 25, 1992
Inventor
Ricky C Hetherington
Northboro
MA, US
Dwight P Manley
Holliston
MA, US
Tryggve Fossum
Northboro
MA, US
Ronald M Salett
Framingham
MA, US
David A Webb Jr
Berlin
MA, US
Wiliam R Grundmann
Hudson
MA, US
Michael M McKeon
Grafton
MA, US
David B Fite
Northboro
MA, US
Mark A Firstenberg
Maynard
MA, US
John E Murray
Acton
MA, US
Agent
Arnold White & Durkee
Assignee
Digital Equipment Corporation
MA, US
IPC
G06F 9/38
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