Yesterday a group of developers were sifting through crash reports that might be related to the new JIT code in Firefox 3.5. We found an unusual set of crashes with EXCEPTION_ILLEGAL_INSTRUCTION. After sifting through these crashes, I found that they have very similar patterns:
- The crashes are all on old processors: the original Pentium, the original AMD K6 (not K6-II or K6-III), or a Via processor. See bug 500277 for the specific family/model/stepping numbers that appear to be affected.
- The crashes all have very low uptime: the browser appears to crash on startup.
Anyone with an original AMD K6 running Linux or Windows, could you please try launching Firefox 3.5 and browsing around the web with it? Please post your results in bug 500277. If you are willing to spend some time diagnosing the problem in a debugger, please email me or join #jsapi on IRC.