Compare and Replace DAT Table Entry
First Claim
1. A computer program product for managing a dynamic address translation (DAT) table, the computer program product comprising:
- computer readable storage medium having program code embodied therewith, the program code readable by a computer processor to perform a method comprising;
determining, by the processor, from an opcode of a machine executable instruction to be executed, that the instruction is a compare and replace DAT table entry instruction, the instructioncomprising an R1 field and an R2 field; and
executing, by the processor, the instruction, the executing comprising;
based on a type field, adding an index value of an odd register to a value of an even register to form an address of a second operand, the odd register and even register being an even-odd register pair designated by the R2 field of the instruction;
obtaining an original second operand from a memory location specified by the formed address;
comparing a first operand and the obtained original second operand, the first operand contained in an even-numbered (even R1) register of an even-odd register pair designated by the R1 field of the instruction;
based on the first operand being equal to the original second operand, storing the contents of the even R1 register in the second operand location as the new second operand.
1 Assignment
0 Petitions
Accused Products
Abstract
A first and a second operand are compared. If they are equal, the contents of register R1+1 are stored at the second-operand location, and the specified CPU or CPUs in the configuration are cleared of all TLB table entries of the designated type formed through the use of the replaced entry in storage, and all lower-level TLB table entries formed through the use of the cleared higher-level TLB table entries. A valid DAT table entry is replaced with a new entry, and the Translation Lookaside Buffer (TLB) is purged of any copies of (at least) the single entry on all CPUs in the configuration. If the first and second operands are unequal, the second operand is loaded at the first-operand location. The comparison result is indicated by the condition code. A method, system and a computer program product are provided.
38 Citations
21 Claims
-
1. A computer program product for managing a dynamic address translation (DAT) table, the computer program product comprising:
-
computer readable storage medium having program code embodied therewith, the program code readable by a computer processor to perform a method comprising; determining, by the processor, from an opcode of a machine executable instruction to be executed, that the instruction is a compare and replace DAT table entry instruction, the instruction comprising an R1 field and an R2 field; and executing, by the processor, the instruction, the executing comprising; based on a type field, adding an index value of an odd register to a value of an even register to form an address of a second operand, the odd register and even register being an even-odd register pair designated by the R2 field of the instruction; obtaining an original second operand from a memory location specified by the formed address; comparing a first operand and the obtained original second operand, the first operand contained in an even-numbered (even R1) register of an even-odd register pair designated by the R1 field of the instruction; based on the first operand being equal to the original second operand, storing the contents of the even R1 register in the second operand location as the new second operand. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A computer system for executing a Compare and Replace DAT Entry instruction, the system comprising:
-
a memory; and a processor configured to communicate with the memory, wherein the computer system is configured to perform a method, the method comprising; determining, by the processor, from an opcode of a machine executable instruction to be executed, that the instruction is a compare and replace DAT table entry instruction, the instruction comprising an R1 field and an R2 field; and executing, by the processor, the instruction, the executing comprising; obtaining an original second operand from a memory location specified by registers of an even-odd register pair designated by the R2 field of the instruction; comparing a first operand and the obtained original second operand, the first operand contained in an even-numbered (even R1) register of an even-odd register pair designated by the R1 field of the instruction; based on the first operand being equal to the original second operand, storing the contents of the even R1 register in the second operand location as the new second operand. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. A computer implemented method for comparing a first and a second address translation table entry, the method comprising:
-
determining, by the processor, from an opcode of a machine executable instruction to be executed, that the instruction is a compare and replace DAT table entry instruction, the instruction comprising an R1 field and an R2 field; and executing, by the processor, the instruction, the executing comprising; obtaining an original second operand from a memory location specified by registers of an even-odd register pair designated by the R2 field of the instruction; comparing a first operand and the obtained original second operand, the first operand contained in an even-numbered (even R1) register of an even-odd register pair designated by the R1 field of the instruction; based on the first operand being equal to the original second operand, storing the contents of the even R1 register in the second operand location as the new second operand. - View Dependent Claims (16, 17, 18, 19, 20, 21)
-
Specification