Abstract: Database processing using columns to present to a processing unit decompressed column data without changing the underlying row-based database architecture. For some embodiments, a database accelerator is used to efficiently process the columns of a database and output tuples to a processing unit's memory, such that the columns can be quickly processed (with the advantages of a column-based architecture) to create tuples of requested data, but without having to depart from a row-based architecture at the processing unit level or having decompressed data scattered throughout the processing unit's memory.

Abstract: Database processing using columns to present to a processing unit decompressed column data without changing the underlying row-based database architecture. For some embodiments, a database accelerator is used to efficiently process the columns of a database and output tuples to a processing unit's memory, such that the columns can be quickly processed (with the advantages of a column-based architecture) to create tuples of requested data, but without having to depart from a row-based architecture at the processing unit level or having decompressed data scattered throughout the processing unit's memory.

Abstract: Database processing using columns to present to a processing unit decompressed column data without changing the underlying row-based database architecture. For some embodiments, a database accelerator is used to efficiently process the columns of a database and output tuples to a processing unit's memory, such that the columns can be quickly processed (with the advantages of a column-based architecture) to create tuples of requested data, but without having to depart from a row-based architecture at the processing unit level or having decompressed data scattered throughout the processing unit's memory.

Abstract: A multi-instruction set architecture (ISA) computer system includes a computer program, a first processor, a second processor, a profiler, and a translator. The computer program includes instructions of a first ISA, the first ISA having a first complexity. The first processor is configured to execute instructions of the first ISA. The second processor is configured to execute instructions of a second ISA, the second ISA being different than the first ISA and having a second complexity, wherein the second complexity is less than the first complexity. The profiler is configured to select a block of the computer program for translation to instructions of the second ISA, wherein the block includes one or more instructions of the first ISA. The translator is configured to translate the block of the first ISA into instructions of the second ISA for execution by the second processor.

Abstract: Database processing using columns to present to a processing unit decompressed column data without changing the underlying row-based database architecture. For some embodiments, a database accelerator is used to efficiently process the columns of a database and output tuples to a processing unit's memory, such that the columns can be quickly processed (with the advantages of a column-based architecture) to create tuples of requested data, but without having to depart from a row-based architecture at the processing unit level or having decompressed data scattered throughout the processing unit's memory.

Abstract: A multi-instruction set architecture (ISA) computer system includes a computer program, a first processor, a second processor, a profiler, and a translator. The computer program includes instructions of a first ISA, the first ISA having a first complexity. The first processor is configured to execute instructions of the first ISA. The second processor is configured to execute instructions of a second ISA, the second ISA being different than the first ISA and having a second complexity, wherein the second complexity is less than the first complexity. The profiler is configured to select a block of the computer program for translation to instructions of the second ISA, wherein the block includes one or more instructions of the first ISA. The translator is configured to translate the block of the first ISA into instructions of the second ISA for execution by the second processor.

Abstract: Executing programs coded in an instruction set of a first computer on a computer of a second, different architecture. An operating system maintains an association between each one of a set of concurrent threads and a set of computer resources of the thread's context. Without modifying a pre-existing operating system of the computer, an entry exception is establishing to be raised on each entry to the operating system at a specified entry point or on a specified condition. The entry exception has an associated entry handler programmed to save a context of an interrupted thread and modify the thread context before delivering the modified context to the operating system. A resumption exception is established to be raised on each resumption from the operating system complementary to one of the specified entries. The resumption exception has an associated exit handler programmed to restore the context saved by a corresponding execution of the entry handler.

Abstract: A computer has instruction pipeline circuitry capable of executing two instruction set architectures (ISA's). A binary translator translates at least a selected portion of a computer program from a lower-performance one of the ISA's to a higher-performance one of the ISA's. Hardware initiates a query when about to execute a program region coded in the lower-performance ISA, to determine whether a higher-performance translation exists. If so, the about-to-be-executed instruction is aborted, and control transfers to the higher-performance translation. After execution of the higher-performance translation, execution of the lower-performance region is reestablished at a point downstream from the aborted instruction, in a context logically equivalent to that which would have prevailed had the code of the lower-performance region been allowed to proceed.

Abstract: A computer. A processor pipeline alternately executes instructions coded for first and second different computer architectures or coded to implement first and second different processing conventions. A memory stores instructions for execution by the processor pipeline, the memory being divided into pages for management by a virtual memory manager, a single address space of the memory having first and second pages. A memory unit fetches instructions from the memory for execution by the pipeline, and fetches stored indicator elements associated with respective memory pages of the single address space from which the instructions are to be fetched. Each indicator element is designed to store an indication of which of two different computer architectures and/or execution conventions under which instruction data of the associated page are to be executed by the processor pipeline.

Abstract: A microprocessor chip has instruction pipeline circuitry, and instruction classification circuitry that classifies instructions as they are executed into a small number of classes and records a classification code value. An on-chip table has entries corresponding to a range of addresses of a memory and designed to hold a statistical assessment of a value of consulting an off-chip table in a memory of the computer. Lookup circuitry is designed to fetch an entry from the on-chip table as part of the basic instruction processing cycle of the microprocessor. A mask has a value set at least in part by a timer. The instruction pipeline circuitry is controlled based on the value of the on-chip table entry corresponding to the address of instructions processed, the current value of the mask, the recorded classification code, and the off-chip table.

Abstract: A computer. A processor pipeline alternately executes instructions coded for first and second different computer architectures or coded to implement first and second different processing conventions. A memory stores instructions for execution by the processor pipeline, the memory being divided into pages for management by a virtual memory manager, a single address space of the memory having first and second pages. A memory unit fetches instructions from the memory for execution by the pipeline, and fetches stored indicator elements associated with respective memory pages of the single address space from which the instructions are to be fetched. Each indicator element is designed to store an indication of which of two different computer architectures and/or execution conventions under which instruction data of the associated page are to be executed by the processor pipeline.

Abstract: A computer. A processor pipeline alternately executes instructions coded for first and second different computer architectures or coded to implement first and second different processing conventions. A memory stores instructions for execution by the processor pipeline, the memory being divided into pages for management by a virtual memory manager, a single address space of the memory having first and second pages. A memory unit fetches instructions from the memory for execution by the pipeline, and fetches stored indicator elements associated with respective memory pages of the single address space from which the instructions are to be fetched. Each indicator element is designed to store an indication of which of two different computer architectures and/or execution conventions under which instruction data of the associated page are to be executed by the processor pipeline.

Abstract: Executing programs coded in an instruction set of a first computer on a computer of a second, different architecture. An operating system maintains an association between each one of a set of concurrent threads and a set of computer resources of the thread's context. Without modifying a pre-existing operating system of the computer, an entry exception is establishing to be raised on each entry to the operating system at a specified entry point or on a specified condition. The entry exception has an associated entry handler programmed to save a context of an interrupted thread and modify the thread context before delivering the modified context to the operating system. A resumption exception is established to be raised on each resumption from the operating system complementary to one of the specified entries. The resumption exception has an associated exit handler programmed to restore the context saved by a corresponding execution of the entry handler.

Abstract: Executing programs coded in an instruction set of a first computer on a computer of a second, different architecture. An operating system maintains an association between each one of a set of concurrent threads and a set of computer resources of the thread's context. Without modifying a pre-existing operating system of the computer, an entry exception is establishing to be raised on each entry to the operating system at a specified entry point or on a specified condition. The entry exception has an associated entry handler programmed to save a context of an interrupted thread and modify the thread context before delivering the modified context to the operating system. A resumption exception is established to be raised on each resumption from the operating system complementary to one of the specified entries. The resumption exception has an associated exit handler programmed to restore the context saved by a corresponding execution of the entry handler.

Abstract: A computer binary translator translates at least a segment of a binary representation of a program from a first instruction set architecture to a second instruction set architecture. A sequence of side-effects in the translation differs from a sequence of side-effects in the original. The translation distinguishes memory loads that are believed to be directed to well-behaved memory from memory loads that are believed to be directed to non-well-behaved memory device(s). Instruction execution circuitry identifies a memory reference that has a side-effect that has been reordered by translation, the memory reference having been believed at translation time to be directed to well-behaved memory but at execution it is found that the reference cannot be guaranteed to be well-behaved. The instruction execution circuitry identifies whether the difference in side-effect order may have a material effect on the execution of the program. A roll-back program state is established, and execution of the original code resumes.

Abstract: Profiling execution of a program. The program is coded in a mode-dependent instruction set. During a profile-quiescent execution interval, the profile circuitry records no profile information. After a triggering event is detected, the profile circuitry commences a profiled execution interval, and records profile information describing every profileable event during that interval. The profiled information includes at least all divergence of execution from sequential execution and processor mode changes not inferable from instruction opcode. The recorded profile information is efficiently tailored to annotate the profiled binary code with sufficient processor mode information to resolve mode-dependency, and indicates contiguous ranges of sequential instructions executed during a profiled interval by low and high boundaries of the contiguous ranges, indicating the high boundary by the address of the last byte.

Abstract: A method and a computer with circuitry configured for performance of the method are disclosed. During a profiled interval of an execution of a program on a computer, profile information is recorded describing the execution, without the program having been compiled for profiled execution. The program is coded in an instruction set in which an interpretation of an instruction depends on a processor mode not expressed in the binary representation of the instruction. The recorded profile information describes at least all events occurring during the profiled execution interval of the two classes: (1) a divergence of execution from sequential execution; and (2) a processor mode change that is not inferable from the opcode of the instruction that induces the processor mode change taken together with a processor mode before the mode change instruction. The profile information further identifies each distinct physical page of instruction text executed during the execution interval.

Abstract: A microprocessor chip, and methods for use in that microprocessor chip. The chip has instruction pipeline circuitry and address translation circuitry. Table lookup circuitry indexes into a table, the table having an entry associated with each corresponding address range translated by the address translation circuitry. Each entry of the table describes a likelihood of the existence of an alternate coding of instructions located in the respective corresponding address range. The table lookup circuitry retrieves a table entry corresponding to the address, and is operable as part of the basic instruction cycle of executing an instruction of a non-supervisor mode program executing on a computer.

Abstract: A computer concurrently executes a first operating system coded in a RISC instruction set and a second operating system coded in a CISC instruction set. When an exception is raised while executing a program coded in the RISC instruction set, an execution thread may be initiated under the CISC operating system. The exception may be delivered to the initiated thread for handling by the CISC operating system.

Abstract: A method and a computer for performance of the method. While executing a program on a computer, profileable events occurring in the instruction pipeline are detected. The instruction pipeline is directed to record profile information describing the profileable events essentially concurrently with the occurrence of the profileable events. The detecting and recording occur under control of hardware of the computer without software intervention.