Other

Amdahl Corporation

Richard Byron Wilmot, Ii

Dieter Gawlick

Arno S Krakauer

John A Colgrove

Extended operand management indicators stored during initial program execution enable management and regulation of operand values and streamline their handling. Operand values are stored in new types of stores. Operand location management indicators indicate current operand value locations among various store types for selected operands. Indicated operand-forwarding policies for selected operands streamline forwarding of operand values from source instructions to value receiving target instructions. Indicated loop iterations of operand source instructions enable forwarding of operands over more than one loop iteration. Stride indicators indicate strides of program loop accesses to matrix operands. Inter-loop indicators enable forwarding of operand values from source loop instructions directly to target loop instructions. Constant or nearly constant operands are indicated to enable their storage in special caches. Operands used for cross-CPU serialization are indicated for special handling and storage in spin lock cache. Indicators of farthest back and farthest forward branches since operand last update are used to enhance the prediction of longer-range branch directions. Virtual predicate operand indicators streamline execution of densely branching program code. Stack operand indicators enable nullification of paired stack pointer increment-decrement operations to avoid serious operand serialization bottlenecks in very high issue rate machines.

Extended operand management indicator structure and method

A method for forwarding operands directly between instructions operates in a computer central processing unit. Values for registers, condition codes, stack locations and memory storage locations are routed directly from the program instructions or microcode that alter them to the instructions that use those operands. Instructions that have received all needed operands are started and their resulting output operands are forwarded to other instructions. With direct forwarding of operands, normal locations for operands may often be skipped so that simpler designs can be employed in constructing the operand storage for register files and stacks. Operands receiving newer values never appear in program-visible locations if the prior values were forwarded to all instructions that might need them and those receiving instructions are completed. In executing program loops, loop-dependent variables are identified. A method is shown whereby multiple loop-dependent operands are computed substantially simultaneously. In favorable circumstances multiple iterations of one or more loops are executed in parallel. The number of iterations is computed and then governs the number of loop iterations executed. Storage of results in architected, generally available areas is avoided where operands are no longer needed after loop iteration execution.

Method and apparatus for annotating operands in a computer system with

A file system for managing data files for access by a plurality of users of a data processing system that includes internal storage for buffering, external storage, and a file user interface by which the plurality of users request access to data files. A first level, coupled to the file user interface in the internal storage allocates the internal storage for temporary storage of data to be accessed by the plurality of users, and generates requests for transactions with external storage in support of such allocations. A second level is coupled to the first level and the external storage and responds to the request for transactions with the external storage for managing the transactions for storage of data to, and retrieval of data from, the external storage. The second level defines a plurality of physical storage classes which are characterized by pre-specified parameters that allocate data files subject of transactions to locations in external memory. In response to requests for transactions, the second level identifies one of the plurality of storage classes assigned to the data file subject of the transaction and carries out the transaction with the appropriate locations in external memory. At least one of the plurality of storage classes provides for utilization of a plurality of access paths in parallel for transactions involving data files assigned to such storage class. Further, at least one parameter pre-specified for storage classes identifies a level of reliability desired for the subject data files.

File system for a plurality of storage classes

A file system for managing data files for access by a plurality of users of a data processing system that includes internal storage for buffering, external storage, and a file user interface by which the plurality of users request access to data files. A first level, coupled to the file user interface in the internal storage allocates the internal storage for temporary storage of data to be accessed by the plurality of users, and generates requests for transactions with external storage in support of such allocations. A second level is coupled to the first level and the external storage and responds to the request for transactions with the external storage for managing the transactions for storage of data to, and retreival of data from, the external storage. The second level defines a plurality of physical storage classes which are characterized by pre-specified parameters that allocate data files subject of transactions to locations in external memory. In response to requests for transactions, the second level identifies one of the plurality of storage classes assigned to the data file subject of the transaction and carries out the transaction with the appropriate locations in external memory. At least one of the plurality of storage classes provides for utilization of a plurality of access paths in parallel for transactions involving data files assigned to such storage class. Further, at least one parameter pre-specified for storage classes identifies a level of reliability desired for the subject data files.

Growing community of inventors

Lafayette, CA, United States of America

Richard Byron Wilmot, Ii