[LLVMdev] LLVM on OpenBSD
mrs at apple.com
Wed Jun 18 11:27:52 PDT 2008
On Jun 18, 2008, at 6:08 AM, Edd Barrett wrote:
> Sometimes you get a clean build of llvm, sometimes you don't and
> get a bus error.
gcc makes a excellent systems test. Try this, while :; do make
boostrap && make clean; done with the FSF top of tree gcc. Let it run
for 2 weeks. If it ever built once, it should never fail to build.
If it does, I'd install a good linux distribution on the same hardware
and try again, if it still fails, look to replace the hardware. If
linux works, I'd look to replace the OS. If it failed everytime in
the exact same spot in the exact same way, try the last FSF release
If it fails deterministically, that could be a gcc bug (or very bad
hardware). If it fails non-deterministically, you're most likely
looking at bad hardware.
> That is one reason a bus error might occur, but my more common
> understanding of a bus error is data not properly aligned with the
> boundaries and/or out of range memory at the physical level.
Absent a bad version of gcc and a bad OS, the usual culprit is bad
> The machine I am building on is my workstation which I use 9-4.30
> mon-fri. I run all manner of apps without any problems, so if it were
> bad hardware it would have shown itself by now surely.
No. I've seen machines that work flawlessly, pass all manner of
memory tests including 24+ hours of standalone memtest86, right up to
the point you ask them to boostrap gcc, then they fail, 100% of the
time. Find someone with good hardware, same OS. See if the testcase
that fails for you, fails for them. Try and use the same gcc binaries
for the test. If it passes for someone else, again, probably bad
If you live in California, I'd ask if you bought you memory at Fry's?
They test all their memory to ensure it is bad, unless you buy the
namebrand memory. :-(
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