Splitting a floating-point stack-exchange instruction for merging into surrounding instructions by operand translation
US5634118A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 10, 1995 |
| Grant date | May 27, 1997 |
| Priority date | — |
| Expiry date | Apr 10, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F9/3017
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A stack-register swap or exchange instruction is executed by splitting the exchange into two halves, and then each half is absorbed into a surrounding instruction by translating its source or destination operands. If one or both surrounding instructions are absent, then one or both halves of the exchange instruction are inserted into the pipeline as separate pipeline flows. When the surrounding instructions are stack-based, the stack operands are first converted to a destination and two source operands that specify a register by absolute number. A translation circuit then translates one of the operands of a surrounding instruction so the surrounding instruction's source is read from the exchange instruction's source, or so that the surrounding instruction's destination is written to the exchange instruction's destination, eliminating the need for processing a separate exchange instruction. Pipelining avoids the need for a temporary register to hold the swap data, since both the register are read early in the pipeline before either instruction over-writes the register.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.