Intel CorporationDownload PDFPatent Trials and Appeals BoardSep 2, 20212020004488 (P.T.A.B. Sep. 2, 2021) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 15/353,549 11/16/2016 Mohammad Abdallah P111987C4 8079 131413 7590 09/02/2021 NDWE LLP/Intel 99 Almaden Boulevard, Suite 575 San Jose, CA 95113 EXAMINER LINDLOF, JOHN M ART UNIT PAPER NUMBER 2183 NOTIFICATION DATE DELIVERY MODE 09/02/2021 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): eofficeaction@appcoll.com ndwe_docketing@cardinal-ip.com patent@ndwe.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte MOHAMMAD ABDALLAH Appeal 2020-004488 Application 15/353,549 Technology Center 2100 ____________ Before LARRY J. HUME, JUSTIN BUSCH, and NORMAN H. BEAMER, Administrative Patent Judges. BEAMER, Administrative Patent Judge. DECISION ON APPEAL Appellant1 appeals under 35 U.S.C. § 134(a) from the Examiner’s final rejection of claims 1, 2, 5, 7–9, 14–16, 19, and 20. Claims 3, 4, 6, 10– 13, 17, 18, and 21 are cancelled. We have jurisdiction over the pending rejected claims under 35 U.S.C. § 6(b). We AFFIRM. 1 We use the word “Appellant” to refer to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the real party in interest as Intel Corporation. (Appeal Br. 2.) Appeal 2020-004488 Application 15/353,549 2 THE INVENTION Appellant’s disclosed and claimed invention is directed to supporting architecture speculation in an out of order processor. (Abstr.) Independent claim 1, reproduced below, is illustrative of the subject matter on appeal: 1. A method for supporting architecture speculation in an out of order processor, the method comprising: fetching two threads into the processor, wherein a first thread executes in a speculative state and a second thread executes in a non-speculative state; and enabling a speculative scope for an execution of the first thread and a non-speculative scope for an execution of the second thread in an architecture of the processor, wherein the speculative scope and the non-speculative scope can both be fetched into the architecture and be present concurrently, wherein in a non-speculative mode, register reads are from committed registers, register writes are to committed registers, and memory writes are written to memory, wherein in a speculative mode, register writes are written to a speculative scratch shadow register, register reads are from a latest write, and memory writes to a retirement memory buffer, and wherein code in the speculative mode can be rolled back if an exception occurs where a state of the speculative scratch shadow register is rolled back to a state of the committed registers. (Appeal Br. 12 (Claims App.).) Appeal 2020-004488 Application 15/353,549 3 REJECTIONS The Examiner rejected claims 1, 2, 5, 7–9, 14–16, and 19 under 35 U.S.C. § 103(a) (pre-AIA) as being unpatentable over Chaudhry et al. (US 2004/0133769 A1, pub. July 8, 2004) and Cain, et al. (US 2011/0238962 A1, pub. Sept. 29, 2011). (Final Act. 2–4.) The Examiner rejected claim 20 under 35 U.S.C. § 103(a) (pre-AIA), as being unpatentable over Chaudhry, Cain, and Mallick et al. (US 5,961,639, iss. Oct. 5, 1999). (Final Act. 4–5.) ISSUES ON APPEAL Appellant’s arguments present the following dispositive issues2: Issue One: Whether the Examiner erred in finding that the combination of Chaudhry and Cain taught or suggested the independent claim 1 requirement, “wherein code in the speculative mode can be rolled back if an exception occurs where a state of the speculative scratch shadow register is rolled back to a state of the committed registers,” and the commensurate requirements of independent claims 7 and 14. (Appeal Br. 5–7.) Issue Two: Whether the Examiner erred in finding that the combination of Chaudhry and Cain taught or suggested the claim 2 requirement, “wherein the speculative scope sets its respective mode differently from the non-speculative scope.” (Appeal Br. 8.) 2 Rather than reiterate the arguments of Appellant and the positions of the Examiner, we refer to the Appeal Brief (filed Oct. 8, 2019); the Final Office Action (mailed May 10, 2019); and the Examiner’s Answer (mailed Jan. 27, 2020) for the respective details. Appeal 2020-004488 Application 15/353,549 4 ANALYSIS We have reviewed the Examiner’s rejections in light of Appellant’s arguments that the Examiner has erred. We disagree with Appellant’s arguments, and adopt as our own, (1) the findings and reasons set forth by the Examiner in the Action from which this appeal is taken (Final Act. 2–5); and (2) the reasons set forth by the Examiner in the Examiner’s Answer in response to Appellant’s Appeal Brief (Ans. 3–5), and concur with the conclusions reached by the Examiner. Issue One The Examiner concedes that Chaudhry alone does not explicitly teach the claim limitation at issue. (Final Act. 3, 4.) However, the Examiner finds that Cain in combination with Chaudhry does so, relying on the disclosure in Cain of an operation for handling an end of a speculative mode of execution in which, “[w]hen a speculative execution has to be aborted or ends unsuccessfully, a roll-back operation is performed such that the state of the registers is returned to a state prior to entry into the speculative execution mode,” including that “all valid entries in the recovery renaming table are written into the register rename table.” (Final Act. 3, 4; Cain Fig. 5, ¶ 44.) The Examiner further finds: At the time of the invention it would have been obvious to one of ordinary skill in the art to combine the teachings of Chaudhry and Cain such that code in the speculative mode can be rolled back if an exception occurs where a state of the speculative scratch shadow register is rolled back to a state of the committed registers. This would have provided an advantage of correcting for possible errors to ensure proper execution. (Final Act. 3.) Appeal 2020-004488 Application 15/353,549 5 Appellant argues that the Examiner erred because the portions of Cain on which the Examiner relies “describe the use of a registry renaming table and a recovery renaming table in connection with a speculative mode of execution,” which relate to mapping logical registers to physical registers. (Appeal Br. 6.) Thus, Appellant argues: These data structures are not equivalent to committed registers and shadow register as recited in claim 1, because they do not serve to handle register reads and writes in the respective modes of operation as expressly recited in claim 1. Rather, these data structures of Cain provide logical to physical mappings to enable the location of data being utilized during speculative execution. The roll-back operation described in Cain operates by rolling back mappings rather than rolling back the values of registers, as recited in claim 1. . . . (Appeal Br. 6–7.) Appellant further argues that the combination of Chaudhry and Cain is improper, because “rolling back speculative execution based on reverting of logical to physical register mappings . . . would change the operating principle of Chaudhry.” (Appeal Br. 7.) In response, the Examiner observes that the claims “only require[] the capability of rolling back register state,” and that “one of ordinary skill in the art certainly would have recognized at least the capability to roll back code or a register state in view of the combination of references.” (Ans. 3.) The Examiner also emphasizes that Cain explicitly discloses that “a roll- back operation is performed such that the state of the registers is returned to a state prior to entry into the speculative execution mode.” (Id.; Cain ¶ 44.) In addition, the Examiner finds: [T]hat exemplary claim 1 does not limit the scope of the claimed “state” to differentiate from a register mapping state. Claim 1 does not provide any specificity regarding what the claimed “state” is that is rolled back. The scope of a register Appeal 2020-004488 Application 15/353,549 6 “state” includes a mapping state. Even if the only rolled back state of the registers in Cain is a mapping state, this would still meet the claim. (Ans. 4.) The Examiner further finds that: [T]he ability to roll back to previous register states would not change Chaudhry’s principle of operation of processing instructions. It would simply require the storage and tracking of checkpoints for restoring a state of the processor. (Id.) Appellant does not rebut these findings, and we are not persuaded that they are in error. Accordingly, we sustain the Examiner’s rejection of independent claims 1, 7, and 14 over the combination of Chaudhry and Cain. We also sustain the Examiner’s rejection of claims 5, 8, 9, 15, 16, and 19 over the combination of Chaudhry and Cain, and of claim 20 over the combination of Chaudhry, Cain, and Mallick, which claims are not argued separately with particularity. (Appeal Br. 8–10.) Issue Two Claim 2 depends from claim 1, and adds the requirement “wherein the speculative scope sets its respective mode differently from the non- speculative scope.” (Appeal Br. 12 (Claims App.).) The Examiner finds that Chaudhry teaches this requirement. (Final Act. 4; Chaudhry, Fig. 3, ¶¶ 50–58.) Appellant argues that the Examiner: does not set forth how the recited “mode” is set differently for the speculative and non-speculative scopes. The use of the shadow register file does not relate explicitly to the setting of the mode and the Patent Office has failed to articulate how the use of the shadow register file or any other aspect of the cited sections of Chaudhry either explicitly or implicitly disclose the different setting of the mode by the two scopes. Appeal 2020-004488 Application 15/353,549 7 (Appeal Br. 8.) The Examiner responds: The claim does not limit the scope of the claimed “mode.” The claim merely requires that there is some difference in the mode of the speculative scope as opposed to the non-speculative scope. Chaudhry describes such a difference of using a shadow register file differently during a speculative scope as opposed to an architectural register file during a non-speculative scope (see e.g.[,] para. [0050-8]). (Ans. 5.) Appellant does not rebut these findings, and we are not persuaded that they are in error. Accordingly, we sustain the Examiner’s rejection of claim 2 over the combination of Chaudhry and Cain. DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1, 2, 5, 7– 9, 14–16, 19 103 Chaudhry, Cain 1, 2, 5, 7– 9, 14–16, 19 20 103 Chaudhry, Cain, Mallick 20 Overall Outcome 1, 2, 5, 7– 9, 14–16, 19, 20 TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv). AFFIRMED Copy with citationCopy as parenthetical citation