Rapid execution of FCMOV following FCOMI by storing comparison result in temporary register in floating point unit
US6393555B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1999 |
| Grant date | May 21, 2002 |
| Priority date | — |
| Expiry date | Aug 5, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3885
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A microprocessor with a floating point unit configured to rapidly execute floating point compare (FCOMI) type instructions that are followed by floating point conditional move (FCMOV) type instructions is disclosed. FCOMI-type instructions, which normally store their results to integer status flag registers, are modified to store a copy of their results to a temporary register located within the floating point unit. If an FCMOV-type instruction is detected following an FCOMI-type instruction, then the FCMOV-type instruction's source for flag information is changed from the integer flag register to the temporary register. FCMOV-type instructions are thereby able to execute earlier because they need not wait for the integer flags to be read from the integer portion of the microprocessor. A computer system and method for rapidly executing FCOMI-type instructions followed by FCMOV-type instructions are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.