Code-specific affiliated register prediction
View Patent ↗Code-specific affiliated register prediction. A determination is made as to whether a unit of code is a candidate for affiliated register prediction. The determining employs a code specific indicator specific to the unit of code. Based on determining the unit of code is a candidate for affiliated register prediction, an indication of an affiliated register is loaded into a selected location. Based on the loading, the affiliated register is employed in speculative processing.
1. A computer program product for facilitating processing within a computing environment, the computer program product comprising:
a computer readable storage medium readable by a processing circuit and storing instructions for performing a method comprising:
determining for a unit of code whether the unit of code is a candidate for affiliated register prediction, wherein the determining employs a code specific indicator specific to the unit of code, wherein the code specific indicator specific to the unit of code is part configuration information associated with the unit of code;
loading into a selected location a location identifier of an affiliated register, based on determining the unit of code is a candidate for affiliated register prediction; and
employing, based on the loading, the affiliated register in speculative processing.
2. The computer program product of claim 1 , wherein another unit of code has another code specific indicator specific to the other unit of code to be used to determine whether the other unit of code is a candidate for affiliated register prediction.
3. The computer program product of claim 1 , wherein the selected location is selected from a group consisting of a machine state register, a program status word, a special purpose register, a page table entry, a segment table entry, and a specific control register.
4. The computer program product of claim 1 , wherein the method further comprises:
determining a context switch has occurred; and
updating a configuration, based on the context switch, wherein the configuration comprises the code specific indicator.
5. The computer program product of claim 4 , wherein the method further comprises:
determining whether the code specific indicator is located in a location specifically bound to the unit of code; and
performing the updating, based on determining the code specific indicator is located in a location not specifically bound to the unit of code.
6. The computer program product of claim 5 , wherein the location specifically bound to the unit of code comprises a page table entry or a segment table entry.
7. The computer program product of claim 5 , wherein the location not specifically bound to the unit of code comprises a control register.
8. The computer program product of claim 1 , wherein the method further comprises:
determining that a hardware exception has been taken; and
storing the configuration information into an exception context, based on the hardware exception, the configuration information comprising the code specific indicator.
9. The computer program product of claim 8 , wherein the method further comprises exiting hardware exception processing, the exiting including:
obtaining the configuration information from the exception context; and
storing the configuration information in a control register.
10. The computer program product of claim 1 , wherein the affiliated register prediction comprises storing a predicted target address of a register-indirect branch in a predicted register and concurrently in an affiliated register that is affiliated with the predicted register on the basis of a known affiliation between the predicted register and the affiliated register.
11. A computer-implemented method of facilitating processing within a computing environment, the computer-implemented method comprising:
determining, by a processor, for a unit of code whether the unit of code is a candidate for affiliated register prediction, wherein the determining employs a code specific indicator specific to the unit of code, wherein the code specific indicator specific to the unit of code is part configuration information associated with the unit of code;
loading into a selected location a location identifier of an affiliated register, based on determining the unit of code is a candidate for affiliated register prediction; and
employing, based on the loading, the affiliated register in speculative processing.
12. The computer-implemented method of claim 11 , wherein another unit of code has another code specific indicator specific to the other unit of code to be used to determine whether the other unit of code is a candidate for affiliated register prediction.
13. The computer-implemented method of claim 11 , further comprising:
determining a context switch has occurred; and
updating a configuration, based on the context switch, wherein the configuration comprises the code specific indicator.
14. The computer-implemented method of claim 13 , further comprising:
determining whether the code specific indicator is located in a location specifically bound to the unit of code; and
performing the updating, based on determining the code specific indicator is located in a location not specifically bound to the unit of code.
15. The computer-implemented method of claim 11 , further comprising:
determining that a hardware exception has been taken; and
storing the configuration information into an exception context, based on the hardware exception, the configuration information comprising the code specific indicator.