Abstract: Data operand fetching control includes a computer processor that includes a control unit for determining memory access operations. The control unit is configured to perform a method. The method includes calculating a summation weight value for each instruction in a pipeline, the summation weight value calculated as a function of branch uncertainty and a pendency in which the instruction resides in the pipeline relative to other instructions in the pipeline. The method also includes mapping the summation weight value of a selected instruction that is attempting to access system memory to a memory access control, each memory access control specifying a manner of handling data fetching operations. The method further includes performing a memory access operation for the selected instruction based upon the mapping.

Abstract: Data operand fetching control includes calculating a summation weight value for each instruction in a pipeline, the summation weight value calculated as a function of branch uncertainty and a pendency in which the instruction resides in the pipeline relative to other instructions in the pipeline. The data operand fetching control also includes mapping the summation weight value of a selected instruction that is attempting to access system memory to a memory access control. Each memory access control specifies a manner of handling data fetching operations. The data operand fetching control further includes performing a memory access operation for the selected instruction based upon the mapping.

Abstract: A method, system and computer program product for verifying a result of a floating point square root operation is provided. The method includes: receiving a result of a floating point square root operation for an operand; performing a comparison of a magnitude of a least significant bit (LSB) of the operand and a magnitude of a most significant bit (MSB) of a remainder; and determining whether the result is correct based on the comparison.

Abstract: A method, system and computer program product for verifying a result of a floating point division operation are provided. The method includes: receiving a result of a floating point division operation for a dividend and a divisor; performing a comparison of a magnitude of a least significant bit (LSB) of the dividend and a magnitude of a most significant bit (MSB) of a remainder; and determining whether the result is correct based on the comparison.

Abstract: A computer processing system method and apparatus having a processor employing an operating system (O/S) multi-task control between multiple user programs and which ensures that the programs do not interfere with each other, said computing processing system having a branch multiple page size prediction mechanism which predicts a page size along with a branch direction and a branch target of a branch for instructions of a processing pipeline, having a branch target buffer (BTB) predicting the branch target, said branch prediction mechanism storing recently used instructions close to the processor in a local cache, and having a translation look-aside buffer TLB mechanism which tracks the translation of the most recent pages and supports multiple page sizes.

Abstract: A method, computer program product and a system for detecting errors in a result of a fixed-point division operation are provided. The method includes: receiving a result of a fixed-point division operation for a dividend and a divisor; performing a first comparison of the divisor and a remainder of the result; performing a second comparison of a sign of the dividend and a sign of the remainder; and determining whether the result is correct based on the first comparison and the second comparison.

Abstract: Several implementations and a design structure for decimal multiplication that uses a BCD 4221 encoding scheme, separate accumulation of partial products, accumulation of the partial products into a final product and conversion from and to a BCD 8421 coding scheme.

Abstract: Machine-based filtering of a pattern history table includes identifying a matching previous occurrence of a current branch instruction in an address history vector (AHV), the AHV storing addresses, or partial addresses, of most recently occurring branch instructions. In response to determining a direction history of the previous occurrence matches a direction history of the current branch, the machine-based filtering includes comparing the outcome of the previous occurrence with the outcome of the current branch instruction, and preventing the pattern history table from being updated with the outcome of the current branch instruction when the outcome of the previous occurrence does not match the outcome of the current branch instruction.

Abstract: A method, computer program product and a system for controlling a fixed point division operation are provided. The method includes: receiving an instruction to perform a division operation for a dividend and a divisor, the operation comprising a maximum number of iterations to produce a quotient having a maximum precision; calculating a magnitude of at least one of the dividend and the divisor; determining a quotient precision based on the magnitude; and computing a required number of iterations needed to produce the quotient precision and performing the number of iterations.

Abstract: A computer processing system method and apparatus having a processor employing an operating system (O/S) multi-task control between multiple user programs and which ensures that the programs do not interfere with each other, said computing processing system having a branch multiple page size prediction mechanism which predicts a page size along with a branch direction and a branch target of a branch for instructions of a processing pipeline, having a branch target buffer (BTB) predicting the branch target, said branch prediction mechanism storing recently used instructions close to the processor in a local cache, and having a translation look-aside buffer TLB mechanism which tracks the translation of the most recent pages and supports multiple page sizes.

Abstract: Machine-based filtering of a pattern history table includes identifying a matching previous occurrence of a current branch instruction in an address history vector (AHV), the AHV storing addresses, or partial addresses, of most recently occurring branch instructions. In response to determining a direction history of the previous occurrence matches a direction history of the current branch, the machine-based filtering includes comparing the outcome of the previous occurrence with the outcome of the current branch instruction, and preventing the pattern history table from being updated with the outcome of the current branch instruction when the outcome of the previous occurrence does not match the outcome of the current branch instruction.

Abstract: A system for data operand fetching control includes a computer processor that includes a control unit for determining memory access operations. The control unit is configured to perform a method. The method includes calculating a summation weight value for each instruction in a pipeline, the summation weight value calculated as a function of branch uncertainty and a pendency in which the instruction resides in the pipeline relative to other instructions in the pipeline. The method also includes mapping the summation weight value of a selected instruction that is attempting to access system memory to a memory access control, each memory access control specifying a manner of handling data fetching operations. The method further includes performing a memory access operation for the selected instruction based upon the mapping.

Abstract: A method for minimizing coupling capacitance between wires in a bus comprising shifting by rearranging the order of said wires in said bus so that, aside from said first and last wires in said arrangement, the coupling capacitance across said bus is uniform and minimized relative to the original arrangement. Alternatively, a method for minimizing coupling capacitance between wires in a bus comprising shifting by rearranging the order of said wires in said bus so that, aside from said first and last wires in said arrangement, one of said wires incurs the smallest possible amount of coupling capacitance and then the coupling capacitance across the rest of said wires in said bus gets progressively worse relative to the original arrangement.

Abstract: Several implementations and a design structure for decimal multiplication that uses a BCD 4221 encoding scheme, separate accumulation of partial products, accumulation of the partial products into a final product and conversion from and to a BCD 8421 coding scheme.

Abstract: A method, computer program product and a system for detecting errors in a result of a fixed-point division operation are provided. The method includes: receiving a result of a fixed-point division operation for a dividend and a divisor; performing a first comparison of the divisor and a remainder of the result; performing a second comparison of a sign of the dividend and a sign of the remainder; and determining whether the result is correct based on the first comparison and the second comparison.

Abstract: A method, system and computer program product for verifying a result of a floating point square root operation is provided. The method includes: receiving a result of a floating point square root operation for an operand; performing a comparison of a magnitude of a least significant bit (LSB) of the operand and a magnitude of a most significant bit (MSB) of a remainder; and determining whether the result is correct based on the comparison.

Abstract: A method, computer program product and a system for controlling a fixed point division operation are provided. The method includes: receiving an instruction to perform a division operation for a dividend and a divisor, the operation comprising a maximum number of iterations to produce a quotient having a maximum precision; calculating a magnitude of at least one of the dividend and the divisor; determining a quotient precision based on the magnitude; and computing a required number of iterations needed to produce the quotient precision and performing the number of iterations.

Abstract: A method, system and computer program product for verifying a result of a floating point division operation are provided. The method includes: receiving a result of a floating point division operation for a dividend and a divisor; performing a comparison of a magnitude of a least significant bit (LSB) of the dividend and a magnitude of a most significant bit (MSB) of a remainder; and determining whether the result is correct based on the comparison.

Abstract: A method for minimizing coupling capacitance between wires in a bus that is shifting by way of rearranging the order of said wires in said bus so that, aside from said first and last wires in said arrangement, the coupling capacitance across said bus is uniform and minimized relative to the original arrangement. Alternatively, a method for minimizing coupling capacitance between wires in a bus that is shifting by way of rearranging the order of said wires in said bus so that, aside from said first and last wires in said arrangement, one of said wires incurs the smallest possible amount of coupling capacitance and then the coupling capacitance across the rest of said wires in said bus gets progressively worse relative to the original arrangement.