James G Mattson

US Patent:

6658486, Dec 2, 2003

Filed:

Feb 25, 1998

Appl. No.:

09/030500

Inventors:

William B. Buzbee - Half Moon Bay CA
James S. Mattson - Campbell CA
Lacky V. Shah - Sunnyvale CA

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 946

US Classification:

709318

Abstract:

A blocking system intercepts communications between a software program and an operating system in order to handle blocking and unblocking of event signals. The blocking system intercepts system calls to the operating system requesting the blocking and unblocking of event signals and keeps track of which event signals are blocked and unblocked without delivering the system calls to the operating system. The blocking system also intercepts event signals from the operating system and only allows unblocked event signals to pass to the software program. Blocked event signals received by the blocking system are discarded until the program unblocks the blocked event signals. After unblocking an event signal, the blocking system determines whether a corresponding event signal was previously received and blocked. If so, the blocking system transmits a signal indicating that the event corresponding to the event signal occurred.

US Patent:

7386861, Jun 10, 2008

Filed:

Jul 23, 2003

Appl. No.:

10/625790

Inventors:

William B. Buzbee - Half Moon Bay CA, US
James S. Mattson - Campbell CA, US
Lacky V. Shah - Sunnyvale CA, US

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06F 9/54
G06F 9/445

US Classification:

719318, 717158, 717145, 717146, 717156

Abstract:

A blocking system intercepts communications between a software program and an operating system in order to handle blocking and unblocking of event signals. The blocking system intercepts system calls to the operating system requesting the blocking and unblocking of event signals and keeps track of which event signals are blocked and unblocked without delivering the system calls to the operating system. The blocking system also intercepts event signals from the operating system and only allows unblocked event signals to pass to the software program. Blocked event signals received by the blocking system are discarded until the program unblocks the blocked event signals. After unblocking an event signal, the blocking system determines whether a corresponding event signal was previously received and blocked. If so, the blocking system transmits a signal indicating that the event corresponding to the event signal occurred.

US Patent:

61013269, Aug 8, 2000

Filed:

May 29, 1997

Appl. No.:

8/865565

Inventors:

James S. Mattson - Campbell CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 945

US Classification:

395709

Abstract:

The invention relates to a method and apparatus for stack frame elimination for simple procedures with tail calls. Subject to certain prerequisite constraints, the invention modifies the procedure by converting all tail calls to direct branches. The code in the computer program for constructing and deconstructing the stack frame is eliminated. In a preferred embodiment of the invention, dead code elimination is performed on unreachable code. In an alternative, equally preferred embodiment, dead code is retained in the computer program.

US Patent:

59110732, Jun 8, 1999

Filed:

Dec 23, 1997

Appl. No.:

8/996963

Inventors:

James S. Mattson - Campbell CA
Lacky V. Shah - Sunnyvale CA
William B. Buzbee - Half Moon Bay CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 9445

US Classification:

395701

Abstract:

A method and apparatus for improving the process of software development by a dynamic software development tool. The present invention allows the execution of an emulation tool to occur under the control of the original user process and preserves the execution flow of the user process instructions. The present invention manages the execution of the emulation tool within the computer memory. The present invention uses the user process code as data to direct the execution of the emulation tool. The present invention enables the use of other software development tools such as monitoring and profiling tools, program analysis tools, simulation tools, and software debugging tools.

US Patent:

63277042, Dec 4, 2001

Filed:

Aug 6, 1998

Appl. No.:

9/130421

Inventors:

James S. Mattson - Campbell CA
Lacky V. Shah - Sunnyvale CA
William B. Buzbee - Half Moon Bay CA
Manuel E. Benitez - Cupertino CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 945

US Classification:

717 9

Abstract:

A computer-implemented system, method, and product are provided for multi-branch backpatching in a dynamic translator. Such backpatching typically increases the speed of execution of translated instructions by providing a direct control path from translated multi-branch-jump instructions to their translated target instructions. In one embodiment, the multi-branch backpatching dynamic translator undertakes backpatching on an "as-needed" basis at run time. That is, backpatching is done for those branch targets that are executed rather than for all branch targets, or rather than for those branch targets that are estimated or assumed will be executed. Such backpatching is accomplished in one embodiment by generating dynamic backpatching code specific to each translated multi-branch-jump instruction. A multi-branch jump, or switch, table of each multi-branch-jump instruction is initialized so that all entries direct control to the dynamic backpatching code for that instruction. As branches of the multi-branch-jump instruction are executed, the dynamic backpatching code enables a backpatcher that replaces the corresponding entry in the translated multi-branch-jump table with pointers to the address of the translated target address, if present.

US Patent:

61158097, Sep 5, 2000

Filed:

Apr 30, 1998

Appl. No.:

9/070442

Inventors:

James S. Mattson - Campbell CA
Lacky V. Shah - Fremont CA
William B. Buzbee - Half Moon Bay CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06F 1500

US Classification:

712239

Abstract:

A method and apparatus varies branch prediction strategy associated with branch instructions in a trace of program code. The present invention first profiles branch instructions within a trace to record branching behavior. Next, the present invention partitions branch instructions into groups of branch instructions that can be statically predicted and groups of branch instructions that can be dynamically predicted. Branch instructions that are profiled to have "strong" branching behavior (e. g. , the same branch direction is taken 80% of the time) are placed in the group of branch instruction that are statically predicted. Branch instructions that are profiled to have "weak" branching behavior (e. g. , the same branch direction is taken 60% of the time) are placed in the group of branch instruction that are dynamically predicted. Finally, branch instructions are adjusted by associating an indication of prediction strategy with each profiled branch instruction.

US Patent:

61648418, Dec 26, 2000

Filed:

May 4, 1998

Appl. No.:

9/073210

Inventors:

James S. Mattson - Campbell CA
Lacky V. Shah - Sunnyvale CA
William B. Buzbee - Half Moon Bay CA
Manuel E. Benitez - Cupertino CA

Assignee:

Hewlett-Packard Company - Palo Alto CA

International Classification:

G06N 945

US Classification:

39550002

Abstract:

A method and apparatus for improving the process of software development by a dynamic software development tool. The present invention efficiently executes in a user process and provides software developers with a high performance tool for software optimization. The present invention may augment the user process code instructions at runtime and, for every series of machine instructions that the original user source code would have executed, a series of instructions may be executed that are semantically equivalent to the user process code instructions and are altered to optimize the user process code instructions. The present invention may use emulation or translation to alter the user process code instructions. The resulting process is executed in the user process space and advantageously maintains the original flow of instruction execution. The present invention employs a technique of dynamically translating code at runtime and may operate on a virtual machine or a hardware machine.

US Patent:

60525304, Apr 18, 2000

Filed:

Feb 25, 1998

Appl. No.:

9/030734

Inventors:

William B. Buzbee - Half Moon Bay CA
James S. Mattson - Campbell CA
Lacky V. Shah - Sunnyvale CA
David A. Dunn - San Jose CA

Assignee:

Hewlett-Packard Co. - Palo Alto CA

International Classification:

G06F 9445

US Classification:

395709

Abstract:

A dynamic translation system is configured to translate existing code into translated code which is compatible with a particular computer system. As the dynamic translation system translates the existing code, the computer system executes the translated code. Once a synchronous fault occurs, the dynamic translation system retranslates the block of code containing the synchronous fault and saves the instruction and state mappings for each instruction capable of causing the synchronous fault. Once the instruction causing the synchronous fault is reached during the retranslation process, the dynamic translation system combines the saved instruction and state mappings of the instruction causing the synchronous error with the current machine state of the computer system to form a simulated machine state. This simulated machine state represents the machine state that would have existed at the time of the synchronous fault if the original code were executing, instead of the translated code. Through techniques known in the art, the computer system utilizes the simulated machine state in order to appropriately process the synchronous fault.