It's not a file, it's a bunch of objects in a directory hierarchy. Think kernel 
modules for nearly everything. 

Ali

Sent from my ARM powered mobile device

On Oct 25, 2011, at 5:04 AM, Gabe Black <[email protected]> wrote:

> Do you know where the solaris kernel actually is on that disk image? I
> can't disassemble it if I don't know which file it is :-P. Ali?
> 
> Gabe
> 
> On 10/25/11 02:30, Gabe Black wrote:
>> Ah, ok, I was just being dumb. All the stdf-s and lddf-s are just moving
>> memory around, I think. That way you can load/store 64 bits at a time
>> and get it done with fewer instructions. I think those instructions
>> themselves can be ignored. I'm also surprised that there would be much
>> floating point.
>> 
>> I'm currently building binutils for SPARC, so hopefully I can
>> disassemble some things and get a better idea of what's going on. It's
>> probably going to be really annoying to figure it out.
>> 
>> Gabe
>> 
>> On 10/25/11 00:32, Steve Reinhardt wrote:
>>> Hard to tell... there are larger and larger differences after that point
>>> that seem to be cascading from this one, but it takes a while before they
>>> diverge completely.  I put the trace in /tmp/tracediff-8625.out on zizzer if
>>> you want to take a look for yourself.
>>> 
>>> It seems odd that the solaris boot would be doing that much FP in any case,
>>> but there does seem to be quite a bit of it.
>>> 
>>> Steve
>>> 
>>> 
>>> On Tue, Oct 25, 2011 at 12:17 AM, Gabe Black <[email protected]> wrote:
>>> 
>>>> An FP rounding error seems very plausible, but I'm not sure how +/- zero
>>>> would make any difference. I'm skeptical that our FP implementation in
>>>> SPARC is accurate enough to care much about such a small difference,
>>>> although it is, of course, entirely possible it cascades from there into
>>>> a larger difference which breaks things.
>>>> 
>>>> I've gone back and improved the SPARC disassembly in the past, but it's
>>>> still not perfect. The problem is the hierarchy that works for getting
>>>> instructions to work doesn't necessarily mirror the one you need to get
>>>> accurate disassembly. I think I went with operand position too (src 0 is
>>>> for this, dest 0 is for that) and that doesn't always work very well.
>>>> That's probably what's going wrong here.
>>>> 
>>>> Is there a point after this where things diverge significantly? This
>>>> could be just a blip of noise and the real problem happens a lot later.
>>>> It's a *major* pain in the butt to write code that theoretically handles
>>>> all the little FP weird cases and gets all the bits right when the host
>>>> ISA has different rules for FP than the guiest, and it's even harder to
>>>> actually get the compiler to generate that code without moving things
>>>> around and messing it all up. And glibc's FP support is wrong sometimes!
>>>> What fun. I largely think it's farther on, and also partially am holding
>>>> out hope we don't have to wade into FP soup.
>>>> 
>>>> Gabe
>>>> 
>>>> On 10/24/11 09:19, Steve Reinhardt wrote:
>>>>> Great, thanks a lot.  I was able to build with
>>>>> 'CC=/usr/bin/gcc-4.4 CXX=/usr/bin/g++-4.4' and get a binary that passes
>>>> this
>>>>> test on the head, so it's definitely the compiler.  I also ran tracediff
>>>> and
>>>>> it looks like it's an off-by-one thing with %fp; here's the first error:
>>>>> 
>>>>> -931697720: system.cpu T0 : 0xff1aa5b8    :     stdf   %fp, [%f29 +
>>>> -0x20] :
>>>>> MemWrite :  D=0x423000000000197a A=0xfeffa280
>>>>> +931697720: system.cpu T0 : 0xff1aa5b8    :     stdf   %fp, [%f29 +
>>>> -0x20] :
>>>>> MemWrite :  D=0x4230000000001979 A=0xfeffa280
>>>>> 
>>>>> (The good gcc-4.4 version is second, so the '1979' is the correct value
>>>>> here.)
>>>>> 
>>>>> I ran one more tracediff with '--debug-flag=All --trace-start=931600000'
>>>> to
>>>>> see if anything else turns up sooner, and got this:
>>>>> 
>>>>> @@ -1380553 +1380553 @@
>>>>> 931697014: system.cpu.[tid:0]: Reading float reg 3 (3) bits as 0, 0.
>>>>> 931697014: system.cpu.[tid:0]: Reading float reg 2 (2) bits as
>>>> 0x3e300000,
>>>>> 0.171875.
>>>>> 931697014: global: FSR read as: 0xc0000000
>>>>> -931697014: system.cpu.[tid:0]: Setting float reg 12 (12) bits to 0, 0.
>>>>> +931697014: system.cpu.[tid:0]: Setting float reg 12 (12) bits to
>>>>> 0x80000000, -0.
>>>>> 931697014: system.cpu.[tid:0]: Setting float reg 13 (13) bits to 0, 0.
>>>>> 931697014: global: FSR written with: 0xc0000000
>>>>> 931697014: system.cpu + A16 T0 : 0xff1aa434    :       fsubd
>>>>> %f31,%f30,%f12    : FloatAdd :  D=0x00000000c0000000
>>>>> @@ -1380951 +1380951 @@
>>>>> 931697038: system.cpu.[tid:0]: Reading float reg 5 (5) bits as 0, 0.
>>>>> 931697038: system.cpu.[tid:0]: Reading float reg 4 (4) bits as 0, 0.
>>>>> 931697038: system.cpu.[tid:0]: Reading float reg 13 (13) bits as 0, 0.
>>>>> -931697038: system.cpu.[tid:0]: Reading float reg 12 (12) bits as 0, 0.
>>>>> +931697038: system.cpu.[tid:0]: Reading float reg 12 (12) bits as
>>>>> 0x80000000, -0.
>>>>> 931697038: global: FSR read as: 0xc0000000
>>>>> 931697038: system.cpu.[tid:0]: Setting float reg 18 (18) bits to 0, 0.
>>>>> 931697038: system.cpu.[tid:0]: Setting float reg 19 (19) bits to 0, 0.
>>>>> @@ -1381022 +1381022 @@
>>>>> 931697042: system.cpu.[tid:0]: Reading float reg 10 (10) bits as
>>>>> 0x41300000, 11.
>>>>> 931697042: global: FSR read as: 0xc0000000
>>>>> 931697042: system.cpu.[tid:0]: Setting float reg 16 (16) bits to
>>>>> 0x41300000, 11.
>>>>> -931697042: system.cpu.[tid:0]: Setting float reg 17 (17) bits to 0xe685,
>>>>> 8.26948e-41.
>>>>> +931697042: system.cpu.[tid:0]: Setting float reg 17 (17) bits to 0xe684,
>>>>> 8.26934e-41.
>>>>> 931697042: global: FSR written with: 0xc0000000
>>>>> 931697042: system.cpu + A16 T0 : 0xff1aa4a4    :       faddd
>>>> %f3,%f2,%f16
>>>>>     : FloatAdd :  D=0x00000000c0000000
>>>>> 931697042: Event_18: AtomicSimpleCPU tick event scheduled @ 931697043
>>>>> 
>>>>> Could it be some kind of FP rounding error?  It's not clear how that
>>>> would
>>>>> end up affecting %fp though.  (Actually, looking at this a little closer,
>>>>> are we even disassembling that correctly?  Seems to me it should be 'stdf
>>>>> %f29, [%fp + -0x20]'.)
>>>>> 
>>>>> I won't have time to look into this further anytime soon, but I hope this
>>>>> will give someone else (Gabe?) enough to go on to get this figured out.
>>>>> 
>>>>> Thanks,
>>>>> 
>>>>> Steve
>>>>> 
>>>>> 
>>>>> On Sun, Oct 23, 2011 at 7:50 PM, Ali Saidi <[email protected]> wrote:
>>>>> 
>>>>>> I've installed it.
>>>>>> 
>>>>>> Ali
>>>>>> 
>>>>>> On Oct 23, 2011, at 7:18 PM, Steve Reinhardt wrote:
>>>>>> 
>>>>>>> This makes sense, since the time the regression started failing is
>>>>>>> consistent with when gcc was upgraded on zizzer.
>>>>>>> 
>>>>>>> I see there is a gcc-4.4 package available for ubuntu 11.04 (which
>>>> zizzer
>>>>>> is
>>>>>>> running)... is there more to it than installing that package and
>>>>>> recompiling
>>>>>>> to get a workable binary to run tracediff with?
>>>>>>> 
>>>>>>> I'd try myself but I've forgotten my zizzer password (again!) so I
>>>> can't
>>>>>>> sudo.  It's tough when you've had the same password for ten years then
>>>>>> you
>>>>>>> change it but don't use the new one much...
>>>>>>> 
>>>>>>> Steve
>>>>>>> 
>>>>>>> On Sun, Sep 25, 2011 at 1:14 PM, Ali Saidi <[email protected]> wrote:
>>>>>>> 
>>>>>>>> Yes.. What Gabe said. With gcc 4.5 (version zizzer now runs) I cannot
>>>>>> find
>>>>>>>> a version of the repository that passes sparc boot.  I'm pretty sure
>>>>>> it's an
>>>>>>>> annoying compiler issue, but there are some annoyances is figuring out
>>>>>> where
>>>>>>>> to look at Gabe points out. If you're stats changes work on everything
>>>>>> else,
>>>>>>>> I'm happy to see them committed while this issue goes on in the
>>>>>> background.
>>>>>>>> Thanks,
>>>>>>>> 
>>>>>>>> Ali
>>>>>>>> 
>>>>>>>> Sent from my ARM powered device
>>>>>>>> 
>>>>>>>> On Sep 25, 2011, at 3:06 PM, Gabe Black <[email protected]>
>>>> wrote:
>>>>>>>>> We (Ali and I) have each looked at that before, and we think it
>>>> depends
>>>>>>>>> on the compiler version. Something changes when you have a new enough
>>>>>>>>> gcc and then the behavior of SPARC changes. I think the new behavior
>>>> is
>>>>>>>>> broken and the old behavior is correct, but I'd have to look at it
>>>>>>>>> again. I haven't looked into it farther than that yet because I'd
>>>> want
>>>>>>>>> to tracediff between versions built with different compilers. Since
>>>>>> they
>>>>>>>>> would need to find different versions of libraries and can't just run
>>>>>>>>> from the same command line, it's logistically annoying.
>>>>>>>>> 
>>>>>>>>> Gabe
>>>>>>>>> 
>>>>>>>>> On 09/25/11 09:52, nathan binkert wrote:
>>>>>>>>>> I'm trying to get my python stats changes into the tree, but it
>>>>>>>>>> appears that one of the regression tests no longer works (zizzer
>>>>>>>>>> agrees with me):
>>>>>>>>>> 
>>>>>>>>>> 
>>>> SPARC_FS/tests/opt/long/80.solaris-boot/sparc/solaris/t1000-simple-atomic
>>>>>>>>>> Gabe, I think you're the only one that's been messing with SPARC.
>>>> Can
>>>>>>>>>> you take a look?
>>>>>>>>>> 
>>>>>>>>>> Nate
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