Mechanism to determine actual code execution flow in a computer
US6173395A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1998 |
| Grant date | Jan 9, 2001 |
| Priority date | — |
| Expiry date | Aug 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/3466
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and system for determining the sequence of execution of instructions in a computer under test using trace data generated upon execution of certain ones of the instructions. In one embodiment, the method comprises locating an initial entry in the trace data and scanning the instructions in program order beginning with an instruction indicated by the initial entry. When a branch instruction is encountered, the trace data is examined to determine the subsequently executed instruction. If the branch is unconditional, a corresponding address entry in the trace data indicates the address of the next instruction. If the branch is conditional, a corresponding bitmap entry in the trace data contains a bit which indicates whether the branch was taken. From this bit and the instructions themselves, the next instruction is determined. The bitmap entry contains a series of bits, each of which can indicate whether a conditional branch was taken, so that a single bitmap entry can represent a series of conditional branches.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.