摘要:
A collector for the results of a pipelined central processing unit of a digital data processing system. The processor has a plurality of execution units, with each execution unit executing a different set of instructions of the instruction repertoire of the processor. The execution units execute instructions issued to them in order of issuance by the pipeline and in parallel. As instructions are issued to the execution units, the operation code identifying each instruction is also issued in program order to an instruction execution queue of the collector. The results of the execution of each instruction by an execution unit are stored in a result stack associated with each execution unit. Collector control causes the results of the execution of instructions to program visible registers to be stored in a master safe store register in program order which is determined by the order of instructions stored in the instruction execution stack on a first-in, first-out basis. The collector also issues write commands to write results of the execution of instructions into memory in program order.
摘要:
A method and a central execution pipeline unit for initiating the execution of instructions of a synchronous central processor unit (CPU) of a general-purpose digital data processing system. Instructions containing address information and an instruction field are obtained in program order from an instruction fetch unit of the CPU. In a first stage, requiring one clock period, the address information of an instruction is utilized to form the carrys and sums of an effective address and to initiate the formation of a virtual address. Concurrently, the instruction field is decoded to produce memory command signals and data alignment signals. In a second stage, the formation of the effective and virtual addresses initiated in the first stage is completed, and the word address portion of the virtual address is transmitted to the cache unit of the CPU. Also during the second stage, memory command signals are sent to the cache unit and the instruction field is converted to an execution code for one of a plurality of execution units, and the execution unit to execute the code is designated. In a third stage, the virtual address is converted to a physical address, or real page number, which is transmitted to the cache unit. The execution code is sent to the designated execution unit; however, if the execution unit is the central unit, the execution unit is the central unit, the execution code for that unit is converted into execution unit control signals. In the fourth stage, data alignment control signals are sent to a distributor of the central execution pipeline unit.
摘要:
Cache memory includes a dual or two part cache with one part of the cache being primarily designated for instruction data while the other is primarily designated for operand data, but not exclusively. For a maximum speed of operation, the two parts of the cache are equal in capacity. The two parts of the cache, designated I-Cache and O-Cache, are semi-independent in their operation and include arrangements for effecting synchronized searches, they can accommodate up to three separate operations substantially simultaneously. Each cache unit has a directory and a data array with the directory and data array being separately addressable. Each cache unit may be subjected to a primary and to one or more secondary concurrent uses with the secondary uses prioritized. Data is stored in the cache unit on a so-called store-into basis wherein data obtained from the main memory is operated upon and stored in the cache without returning the operated upon data to the main memory unit until subsequent transactions require such return.
摘要:
A one's complement adder for adding two binary numbers A.sub.i, B.sub.i in the one's complement system is constructed from a conventional adder circuit by connecting the generate output signal G produced by the adder to the carry-in terminal of the adder. The value of the generate signal is independent of the signal applied to the carry-in terminal which prevents the adder from exhibiting sequential or indeterminate behavior.
摘要:
Method and apparatus for calculating the residue of a signed binary number of "n" bits with respect to a given check base m where m=2.sup.b -1. The bits of the binary number excluding the sign bit are partitioned into number segments, each of b bits starting with the least significant bit. If (n-1) is not an even multiple of b, higher order bit positions of the number segment containing the next most significant bit of the binary number are filled with logical zeros. A sign segment of b bits is formed. Both number and sign segments have boundaries. The bit position in the sign segment relative to a sign segment boundary which corresponds to the bit position of the sign bit "s" relative to the nearest boundary of a number segment is filled with a logical zero. All other bit positions of the sign segment are filled with the sign bit. The number and sign segments are applied to carry save adders to reduce the number segments and sign segment to a single sum segment and a single rotated carry segment. A rotated carry segment is a carry segment produced by a carry save adder, the most significant bit of which becomes the least significant bit of the rotated carry segment. The other bits of the carry segment and their significance are increased by one in the rotated carry segment. Carry segments produced by carry save adders of one level are converted to rotated carry segments before being applied to a carry save or full adder of a lower level. The single sum segment and single rotated carry segment produced by the lowest level carry save adder is applied to a one's complement adder. The b bit output of the one's complement adder is the residue of the signed binary number to the check base (2.sup.b -1).
摘要:
A method and apparatus is disclosed for compilation of an original Cobol program with support for improved performance by increased parallelism during execution using multiple threads of processing. The approach includes a two stage compilation process, the first compilation/translation step by a first specialized compiler/translator that takes as input a Cobol source program that includes parallelization directives, and produces as output an intermediate computer program in a second computer programming language, the intermediate program including parallelization directives in the second computer programming language. The intermediate program is then compiled utilizing a selected second compiler that provides support for parallelism described in the second programming language. The approach optionally allows for use of pragmas serving as parallelization directives to the compiler in the original Cobol program or in the intermediate program.
摘要:
A method and apparatus is disclosed providing an improvement in performance for arithmetic computations by a computer system for calculations which include decimal numeric variables. The improvement in at least one embodiment includes use of a special compiler in cooperation with a special decimal numeric subroutine library. The compiler provides comparative alignment information based upon comparing alignments of a plurality of decimal variables. The decimal subroutine library can then provide improved performance at run time by utilizing the information compared by the compiler at compiler time rather than making those computations repeatedly at run time.
摘要:
A method and apparatus is disclosed providing an improvement in performance for arithmetic computations by a computer system for calculations which include decimal numeric variables. The improvement in at least one embodiment includes use of a special compiler in cooperation with a special decimal numeric subroutine library. The compiler provides comparative alignment information based upon comparing alignments of a plurality of decimal variables. The decimal subroutine library can then provide improved performance at run time by utilizing the information compared by the compiler at compiler time rather than making those computations repeatedly at run time.
摘要:
In order to validate data manipulation results in a CPU which incorporates duplicate BPUs for integrity, which BPUs are typically each implemented on a single VLSI circuit chip, and which is capable of performing single and double precision data manipulation operations, two cache units are employed. Each cache unit is dedicated to handling half-bytes of information and incorporates highly reliable data validating logic without the necessity for providing double word wide output busses from each BPU. This feature, which lowers the lead count to each VLSI chip, is obtained by dedicating each cache unit to handling half-bytes of information. Each cache unit includes bit-by-bit comparison circuitry to validate the half-byte results received from both BPUs in the case of single precision operations, and, in the case of double precision operation, one cache unit employs the same bit-by-bit comparison circuitry to validate, for both cache units, the result parity bits, and hence the half-byte results, received from both BPUs.
摘要:
A method is disclosed for translating by a computer system of a COBOL computer program into a translated computer program in a readable and maintainable syntax in an object oriented programming language. The translated program including variable names equivalent to the original COBOL variable names and with attributes described in COBOL syntax. The translating method further providing for memory allocation in the translated computer program for storage of “COBOL” variables compatible with that of the original COBOL program; a description of program flow that is readable, and utilizing arithmetic operators to describe operations between COBOL variables. Also disclosed is a special object oriented run-time library for creating and performing operations between COBOL numeric objects, including maintaining storage of variable content in the original COBOL format, and for enabling readability of the translated source code by allowing arguments for variable type descriptions to be expressed in COBOL syntax.