[LLVMdev] llvm-gcc bootsrtap on ARM

Dale Johannesen dalej at apple.com
Fri Nov 2 10:26:11 PDT 2007

On Nov 2, 2007, at 2:43 AM, Rafael Espindola wrote:

> Hello,
> I am trying to bootstrap on ARM linux EABI using a qemu chroot to
> better test my changes on at least one more architecture.
> I am using the following configure line:
> ../gcc/configure --prefix=/home/espindola/install/
> --program-prefix=llvm- --enable-languages=c --disable-shared
> --disable-multilib --enable-llvm=/home/espindola/build
> --enable-checking arm-linux-gnueabi
> The bootstrap fails in the most annoying point possible, a compare
> difference between arm.o in stages 2 and 3.

Interesting.  Evan and I were seeing a similar miscompare (on a
different file, obviously) on x86 Darwin about 2 weeks ago.  In our
case it went away with patch 43367, so I haven't pursued figuring
out what the problem was, but it's quite possible that patch just hid
the problem instead of fixing it.

In our case the difference in the files was only about 10 instructions,
and both versions were functionally correct.  It appeared the induction
variable code was making a different choice in a case where it could
have used either of 2 induction variables.   Could you diff your .o's  
see if this looks like the same problem?

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