Efficient quantization of compare results

Patent metadata

Field	Value
Publication number	US-2016378485-A1
Application number	US-201514869816-A
Country	US
Kind code	A1
Filing date	Sep 29, 2015
Priority date	Jun 24, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

A set machine instruction is provided that has associated therewith a result location to be used with a set operation. The set machine instruction is executed, which includes checking contents of a selected field, and determining, based on the checking, whether the contents of the selected field indicate a first condition, a second condition or a third condition represented in one data type. The result location is set to a value based on the determining, wherein the value, based on the setting, is of a data type different from the one data type and represents a result of a previously executed instruction. The result of the previously executed instruction being one of the first condition, the second condition or the third condition.

First claim

What is claimed is:

1 . A computer-implemented method of executing a machine instruction in a computing environment, the computer-implemented method comprising:
obtaining, by a processor, a machine instruction to perform a set operation, the machine instruction having associated therewith a result location to be used for the set operation; and executing, by the processor, the machine instruction, the executing comprising:
checking contents of a selected field;
determining, based on the checking, whether the contents of the selected field indicate a first condition, a second condition or a third condition represented in one data type; and
setting the result location to a value based on the determining, wherein the value, based on the setting, is of a data type different from the one data type and represents a result of a previously executed instruction, the result of the previously executed instruction being one of the first condition, the second condition or the third condition.

2 . The computer-implemented method of claim 1 , wherein the value is equal to a first value based on the determining indicating the first condition, equal to a second value based on the determining indicating the second condition, and equal to a third value based on the determining indicating the third condition.

3 . The computer-implemented method of claim 1 , wherein the machine instruction is a single architected instruction implemented with combinatorial logic.

4 . The computer-implemented method of claim 1 , wherein the determining comprises:
checking whether a first selected bit of the contents is equal to one value, and based on the first selected bit equaling the one value, setting the value equal to a first value; based on the first selected bit equaling another value, determining whether a second selected bit of the contents is equal to the one value, and based on the second selected bit equaling the one value, setting the value equal to a second value; and based on the first selected bit and the second selected bit equaling the other value, setting the value equal to a third value.

5 . The computer-implemented method of claim 4 , wherein the first value comprises −1, the second value comprises 1, and the third value comprises 0.

6 . The computer-implemented method of claim 1 , wherein the setting the result location comprises placing the value in a register designated by a result field of the machine instruction.

7 . The computer-implemented method of claim 1 , wherein the first condition comprises a less than condition, the second condition comprises a greater than condition, and the third condition comprises an equal condition.

8 . The computer-implemented method of claim 1 , wherein the selected field is a field within a condition register, the condition register comprising a plurality of fields to include a plurality of condition codes, the selected field including a condition code of the plurality of condition codes, and wherein the machine instruction comprises a selection field to include a selection indicator, the selection indicator to select the selected field.

9 . The computer-implemented method of claim 1 , wherein the selected field is a field of one of a program status word, a condition register or a flags field.

10 . The computer-implemented method of claim 1 , wherein the previously executed instruction comprises a compare instruction, wherein based on execution of the compare instruction, a condition code is placed in the selected field.

Assignees

• IBM

Inventors

• Gschwind Michael K
• Olsson Brett

Classifications

• G06F9/30181 Primary

  Instruction operation extension or modification · CPC title

• G06F9/30072

  to perform conditional operations, e.g. using predicates or guards · CPC title

• G06F9/30021

  Compare instructions, e.g. Greater-Than, Equal-To, MINMAX · CPC title

• G06F9/30094 Primary

  Condition code generation, e.g. Carry, Zero flag · CPC title

• G06F9/30025

  Format conversion instructions, e.g. Floating-Point to Integer, decimal conversion · CPC title