Performing variable and/or bitwise shift operation for a...

Details Performing variable and/or bitwise shift operation for a... Performing variable and/or bitwise shift operation for a...

2006-06-05

2009-10-27

Li, Aimee J (Department: 2183)

Electrical computers and digital processing systems: processing

Processing control

Logic operation instruction processing

C708S209000

Reexamination Certificate

active

07610472

ABSTRACT:
Some embodiments present a method of performing a variable shift operation. This method can be used by a microprocessor that does not allow variable shift operation for certain operand sizes. The method simulates a shift instruction that shifts an operand by a shift count. The method identifies a first shift command and a second shift command. The method computes a mask value. The mask value depends on whether the shift count is less than half of the operand size or greater than or equal to half of the operand size. The method uses the mask value to cause one of the first shift command and the second shift command to produce no shift. In some embodiments, the method allows for the shift count to be specified in bytes or in bits.

REFERENCES:
patent: 4785393 (1988-11-01), Chu et al.
patent: 5479527 (1995-12-01), Chen
patent: 5526296 (1996-06-01), Nakahara et al.
patent: 5642115 (1997-06-01), Chen
patent: 5651121 (1997-07-01), Davies
patent: 5812701 (1998-09-01), Chen
patent: 5913229 (1999-06-01), Joo
patent: 6223277 (2001-04-01), Karguth
patent: 2003/0041229 (2003-02-01), Sandbote
patent: 2004/0008711 (2004-01-01), Lahti et al.
patent: 649224 (1995-04-01), None
Intel. “IA-32 Intel® Architecture Software Developer's Manual vol. 2: Instruction Set Reference”. © 2003. p. 3-624.

Affiliated with

Also associated with

Rating

Performing variable and/or bitwise shift operation for a... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Performing variable and/or bitwise shift operation for a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Performing variable and/or bitwise shift operation for a... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4094053