Thanks Steve, I've looked at the other ISAs and that is what appears to be happening so I'll try that out here too.
Tim On Mon, 19 Oct 2009 18:04:12 +0100, Steve Reinhardt <[email protected]> wrote: > Hi Tim, > > That assertion is just letting you know that it doesn't make sense to > translate a request that crosses a page boundary. I'm guessing that in > our > other RISC ISAs we check alignment first, so you get an alignment fault > before you even try to translate the access. The alignment fault will > then > be properly ignored if the instruction turns out to be misspeculated. > > Steve > > On Mon, Oct 19, 2009 at 7:10 AM, Timothy M Jones > <[email protected]>wrote: > >> Hi everyone, >> >> I'm getting an assertion failure in the top of >> PageTable::translate(RequestPtr req) when running one of my PowerPC >> binaries on O3CPU. This is the offending assertion: >> >> assert(pageAlign(req->getVaddr() + req->getSize() - 1) >> == pageAlign(req->getVaddr())); >> >> If I comment this out and put in a DPRINTF, it turns out that the >> problem >> is this: >> >> 39789018: system.cpu.iew.lsq.thread.0: Executing store PC 0x1002fb38 >> [sn:67277] >> 39789018: global: RegFile: Access to int register 57, has data >> 0xffffffff >> 39789018: global: RegFile: Access to int register 232, has data 0x9 >> 39789018: global: Would fail assertion in PageTable::translate >> 39789018: global: Couldn't Translate: 0xffffffff >> 39789018: system.cpu.iew.lsq.thread.0: Fault on Store PC 0x1002fb38, >> [sn:67277], >> Size = 0 >> >> Later on, this store gets squashed because of a branch misprediction. >> >> Should this assertion be failing, even for speculative instructions? If >> so, then I'm guessing that I've got a problem with the store being >> scheduled too early. If not, then is it safe to remove or modify the >> assertion to account for speculation? >> >> Thanks >> Tim >> >> -- >> The University of Edinburgh is a charitable body, registered in >> Scotland, with registration number SC005336. >> >> _______________________________________________ >> m5-dev mailing list >> [email protected] >> http://m5sim.org/mailman/listinfo/m5-dev >> -- The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336. _______________________________________________ m5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/m5-dev
