Hello,

We've been investigating very large prefetch depths in system emulation mode 
and came across an interesting phenomenon. Under a subset of benchmarks and 
configurations, segmentation faults (panic: tried to access unmapped address) 
are observed. 

Previous posts on "tried to access unmapped address" suggest that it may have 
been caused by cache data corruption, and we are wondering if the following 
situation is plausible. 

O3CPU (detailed sim) speculatively accesses a piece of data which in turn 
prefetches a bunch of data ahead of the CPU. Because these data are so much 
ahead of the execution path, the data values are uninitialized and hence 
corrupt data. We are suspecting this because it works fine with timing 
simulation. 

Has anyone encountered this situation with O3CPU with large issue width and 
large prefetch depths? Thanks!

-Bryan
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