Apparatus and method for handling tiny numbers using a super sticky bit in a microprocessor
US6374345B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1999 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Jul 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F7/49952
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for handling tiny numbers using a super sticky bit are provided. In response to detecting that a preliminary result of an instruction corresponds to a tiny number and an underflow exception is masked, an execution pipeline can be configured to store a value corresponding to the preliminary result and a super sticky bit in a destination register. Also, a destination register tag corresponding to the destination register and a denormal exception indicator corresponding to the tiny number and masked underflow exception can be stored. A trap handler can be initiated to generate a corrected result for the instruction. The trap handler can detect that the denormal exception indicator has been set and can read the value and the super sticky bit from the destination register using the destination register tag. The trap handler can generate a corrected result for the instruction based on the value and the super sticky bit. An instruction subsequent to the trapping instruction can then be restarted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.