Preserving the content of a first register without affecting the content of a second register
AssigneeHewlett-Packard Development Company, L.P.
InventorsJenn-Yuan Tsai, Vinodha Ramasamy
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Abstract
Techniques are disclosed for preserving first content in a first register. In one embodiment, the first register is a general register, a second register is a UNaT register, and each general register is associated with a NaT bit. To preserve the content of the UNaT register while saving the content of a general register and its associated NaT bit, the content of the general register is saved to a floating-point register, and the NaT bit associated with the general register is also saved. If the NaT bit is set, then only the NaT bit is restored. Conversely, if the NaT bit is not set, then both the content of the general register and the NaT bit are restored.
Claims18
A method for preserving first content in a first register while maintaining second content in a second register, the method comprising the steps of:
- saving the first content to a third register;
- modifying the first content in the first register;
- and
- restoring the first content saved in the third register to the first register when a value associated with the first register is in an unset state;
- wherein
- saving the first content to a particular location other than the third register changes the second content in the second register;
- and
- saving the first content to the third register maintains the second content in the second register.
A method for preserving first content in a first register while maintaining second content in a second register, the method comprising the steps of:
- saving the first content and a value associated with the first register to a third register;
- modifying the first content in the first register;
- and
- restoring the value associated with the first register saved in the third register to that value's original location at the time that value was saved;
- wherein saving the first content to a particular location other than the third register changes the second content in the second register;
- and saving the first content to the third register maintains the second content in the second register.
A computer-readable medium embodying program instructions to perform a method for preserving first content in a first register while maintaining second content in a second register, the method comprising the steps of:
- saving the first content to a third register;
- modifying the first content in the first register;
- and
- restoring the first content saved in the third register to the first register when a value associated with the first register is in an unset state;
- wherein
- saving the first content to a particular location other than the third register changes the second content in the second register, and
- saving the first content to the third register maintains the second content in the second register.
Dependencies are inferred from the claim text.