Hi Neil,

On Thu, Apr 25, 2002 at 08:49:47PM +1000, Neil Brown wrote:

On Thursday April 25, beezly@beezly.org.uk wrote:
That's two reports of this.  It looks to me very much like a compiler
bug.   I'm not an export on Sparc assembler, but I've just been
reading through the disassembly listing of read1_read_balance,
and at least two things look wrong:

0xc30 <raid1_read_balance+208>: sllx  %o2, 3, %g2 
0xc34 <raid1_read_balance+212>: add  %i1, 0x20, %g3
0xc38 <raid1_read_balance+216>: clr  [ %i5 + 0x3f0 ]
0xc3c <raid1_read_balance+220>: add  %g2, %o2, %g2

This is the only place that %o2 is used, and it is never
initialised.

0xbac <raid1_read_balance+76>:  add  %i5, 0x18, %o7
0xbb0 <raid1_read_balance+80>:  sllx  %o7, 3, %g2

%i5 is holding "conf". adding 0x18 gives the address of
 conf->mirrors[0]->head_position in %o7.
But then we shift %o7 left 3 places, multiplying by 8.
Multiplying an address by 8 is very unlikely to be correct.

Could you both please tell us what compiler version you are using, and
see if you can try a different one.

andy@lemur:~$ sparc64-linux-gcc -dumpversion
egcs-2.92.11

I'm trying a build with gcc-3 right now, I have a gcc-2.95 compiler
also, but it doesn't support building 64 bit binaries.

Cheers,

Beezly