[M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
Jay K
jay.krell at cornell.edu
Sat May 15 03:29:01 CEST 2010
Well I'm feeling dumb. That test case surely would print 1 for almost anything.
A more accurate one, which shows a problem, is:
#include <stdio.h>
unsigned F1(unsigned a) { return ((a>> 22) & 1); }
unsigned F2(unsigned a) { return ((a << 22)>> 31); }
int main()
{
unsigned a = 1 << 22;
printf("%x %x\n", F1(a), F2(a));
return 0;
}
But I'm still having trouble convincing myself.
I guess the second might give you the 10th bit.
Er, the 9th.
#include <stdio.h>
unsigned F1(unsigned a) { return ((a>> 22) & 1); }
unsigned F2(unsigned a) { return ((a << 22)>> 31); }
int main()
{
unsigned a = 1 << 22;
printf("%x %x\n", F1(a), F2(a));
a = 1 << 9;
printf("%x %x\n", F1(a), F2(a));
return 0;
}
1 0
0 1
- Jay
----------------------------------------
> From: jay.krell at cornell.edu
> To: hosking at cs.purdue.edu
> Date: Sat, 15 May 2010 01:07:27 +0000
> CC: m3devel at elegosoft.com
> Subject: Re: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>
>
>> < srl %g1, 22, %g1
>> < and %g1, 1, %g1
>> ---
>>> sll %g1, 22, %g1
>>> srl %g1, 31, %g1
>
> Er.
> first: a = (a>> 22) & 1;
> second: a = (a << 22)>> 31;
>
> are actually darn close, maybe the same.
> Let's just be lame and test in C:
>
> #include
> int main()
> {
> unsigned a = ~0;
> unsigned b = (a>> 22) & 1;
> unsigned c = (a << 22)>> 31;
> printf("%x %x\n", b, c);
> return 0;
> }
>
> both print 1. So I remain a bit uncertain.
> I think undoing just that one change made it go between working and not working, but I also often lose track of what I've cleaned vs. rebuilt.
> I might dig more before commiting the undo.
> Maybe bit fields of multiple bits are the only ones broken.
>
> - Jay
>
>
> ----------------------------------------
>> From: jay.krell at cornell.edu
>> To: hosking at cs.purdue.edu
>> Date: Sat, 15 May 2010 00:24:03 +0000
>> CC: m3devel at elegosoft.com
>> Subject: Re: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>>
>>
>> Tony I think it is your change to extract_mn.
>> Try it with SOLsun for example.
>> I see these sorts of differences repeatedly (not to mention works vs. not works, having only undone that change):
>>
>>
>> diff cm3-boot-SOLsun-1/Abs.ms cm3-boot-SOLsun-2/Abs.ms
>> 77,78c77,78
>> < srl %g1, 22, %g1
>> < and %g1, 1, %g1
>> ---
>>> sll %g1, 22, %g1
>>> srl %g1, 31, %g1
>> 118,119c118,119
>> < srl %g1, 22, %g1
>> < and %g1, 1, %g1
>> ---
>>> sll %g1, 22, %g1
>>> srl %g1, 31, %g1
>> 197,198c197,198
>> < srl %g1, 21, %g1
>> < and %g1, 1, %g1
>> ---
>>> sll %g1, 21, %g1
>>> srl %g1, 31, %g1
>> 236,237c236,237
>> < srl %g1, 22, %g1
>> < and %g1, 1, %g1
>> ---
>>> sll %g1, 22, %g1
>>> srl %g1, 31, %g1
>> 273,274c273,274
>> < srl %g1, 22, %g1
>> < and %g1, 1, %g1
>>
>>
>> This is not optimized.
>> They seem equally optimal, but very different.
>> Assuming shifts are fast. Could be srl+and is faster than sll+srl.
>> srl+and is clearer.
>> I don't remember which of these worked.
>>
>>
>> < srl %g1, 22, %g1
>>
>> < and %g1, 1, %g1
>>
>> ---
>>
>>> sll %g1, 22, %g1
>>
>>> srl %g1, 31, %g1
>>
>>
>>
>> I read the first as:
>> extract bit 22, plus or minus 1
>> vs.
>> extract bit 32-22=10, plus or minus 1.
>>
>>
>> It would probably be ok to move bits around, but insert would have to match.
>>
>>
>> - Jay
>>
>>
>> ----------------------------------------
>>> From: jay.krell at cornell.edu
>>> To: hosking at cs.purdue.edu
>>> Date: Fri, 14 May 2010 22:13:58 +0000
>>> CC: m3devel at elegosoft.com
>>> Subject: Re: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>>>
>>>
>>> So maybe I386_LINUX is ok..but others not..I need to test more/again/more/again/more/again....
>>>
>>> - Jay
>>>
>>> ----------------------------------------
>>>> From: jay.krell at cornell.edu
>>>> To: hosking at cs.purdue.edu
>>>> CC: m3devel at elegosoft.com
>>>> Subject: RE: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>>>> Date: Fri, 14 May 2010 18:25:59 +0000
>>>>
>>>>
>>>> I should disclose that I also rolled back hand.c, though that is mostly or completely implied, due to mod/div/set.
>>>>
>>>>
>>>> I have some extra time today, so, plan:
>>>> retest head on I386_LINUX (still crossing from Darwin/x86), verify it is broken, since it is all working now
>>>> test undo just the bitfield insert/extract change, see if that is the problem
>>>> work through the others if not
>>>> Possibly verify mod/div test coverage (unless it is the problem, in which
>>>> case if I put it back, no need for test coverage, probably nobody will ever
>>>> touch it again, which is fine. :) )
>>>> I'm pretty sure I tested the set stuff well because I was very nervous but
>>>> if others are ruled out I'll undo or test it.
>>>> (To clarify, I wasn't even sure by close inspection of the correctness of my NT386
>>>> set changes. Only through experimentation/testing could I know that
>>>> the definition of bit indices matched up between hand.c and the btc/bts instructions,
>>>> it appeared to be a very convenient coincidence.)
>>>>
>>>>
>>>> I am surprised that I386_* working and broken.
>>>> I would think wordsize and endian is all that matters here.
>>>>
>>>>
>>>> I do worry that we are only on gcc 4.3.0 and not even 4.3.3.
>>>> But moving up to 4.4.x or 4.5.x is welcome too. :)
>>>>
>>>>
>>>> - Jay
>>>>
>>>>
>>>> ----------------------------------------
>>>>> From: jay.krell at cornell.edu
>>>>> To: hosking at cs.purdue.edu
>>>>> Date: Fri, 14 May 2010 17:58:29 +0000
>>>>> CC: m3devel at elegosoft.com
>>>>> Subject: Re: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>>>>>
>>>>>
>>>>> I don't think anything I've been fiddling with has been dropped by gcc, yet.
>>>>> I might have depended on Irix o32 to get up to a working gcc, but no matter.
>>>>> I agree if they drop it, we have to.
>>>>> Though we could also keep multiple gcc versions if there was really something we wanted,
>>>>> but that's not likely.
>>>>> A C generating backend also solves this.
>>>>>
>>>>>
>>>>> I think I tested my "set" changes on 32bit, 64bit, little endian, big endian, all four combinations.
>>>>> But I won't guarantee that now and am very willing to undo them if there is a problem.
>>>>> (big endian 64bit would be PPC64_DARWIN, which does have a strong propensity to hang, but also largely works).
>>>>>
>>>>>
>>>>> I don't remember about div/mod.
>>>>> While it seems "obvious" that the change is correct, it could be that that part of
>>>>> gcc is little tested: C and Fortran wouldn't use it. But maybe Ada?
>>>>>
>>>>>
>>>>> I'm also not optimizing at all.
>>>>>
>>>>>
>>>>> I also agree that rolling forward to any newer gcc is welcome. I just don't know how to do it, at least not
>>>>> easily, and I'm also not keen on the huge testing matrix.
>>>>> (I think it's roughly what I did for Apple's gcc 4.2, but it was tedious.)
>>>>>
>>>>>
>>>>> If it is ICEs we are after though, it is fairly easy to do cross builds and test "everything", automated, given the time to build gcc enough times. :)
>>>>> We should really fix the few lingering 32bit/64bit cross bugs, so we can cross build everything.
>>>>>
>>>>>
>>>>> Rolling back parse.c, I think every target I've tested (running cm3 bootstrap and making
>>>>> sure it gets as far as "can't find cm3.cfg") has worked, except PPC32_OPENBSD.
>>>>> This includes PPC_DARWIN, PPC64_DARWIN, I386_LINUX, SPARC64_SOLARIS,
>>>>> SPARC64_OPENBSD. (SPARC64_SOLARIS now probably working).
>>>>>
>>>>>
>>>>> - Jay
>>>>>
>>>>> ----------------------------------------
>>>>>> From: hosking at cs.purdue.edu
>>>>>> Date: Fri, 14 May 2010 09:59:02 -0400
>>>>>> To: jay.krell at cornell.edu
>>>>>> CC: m3devel at elegosoft.com
>>>>>> Subject: Re: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>>>>>>
>>>>>> Argh. I worried about that when I made my changes, but all seemed to be well for bootstraps on Darwin/x86.
>>>>>>
>>>>>> Also, we need to have regular testing of the compiler at both -O1 and -O2 or -O3 optimisation levels. I know of at least one gcc ICE on one platform (I forget which) that manifests only at -O3 compiling just one module in the entire CM3 distribution. This is fragile stuff... and it may just be a bug in gcc that we are exercising.
>>>>>>
>>>>>> It may be that we just need to update the backend to a newer version of gcc. It has been a couple of years, and Jay is pushing the target envelope much further than it ever has been. Problem is that newer gcc may not play nice with older targets. I strongly suggest that we focus effort on modern targets and not older targets, which implies we probably want to roll the gcc-based backend forward to a more current gcc release.
>>>>>>
>>>>>> On 14 May 2010, at 06:27, Jay K wrote:
>>>>>>
>>>>>>>
>>>>>>> ok, bringing parse.c mostly back to what it is in release, has cleared up a lot of this, I haven't nested it all.
>>>>>>> Then I'll have to narrow it down some -- there are two main sets of changes:
>>>>>>> - my changes to set operations
>>>>>>> - my change to div/mod
>>>>>>> - Tony's to bit field operations
>>>>>>>
>>>>>>> It is also conceivable that mixing release/head cm3 with head/release cm3cg 1) doesn't work 2) I was doing it.
>>>>>>>
>>>>>>> I thought I had tested my changes thoroughly but at this point, I don't know, and don't care much
>>>>>>> to keep them if they don't work.
>>>>>>> (Well, hopefully the NT386 versions can stay. :) )
>>>>>>>
>>>>>>> - Jay
>>>>>>>
>>>>>>>
>>>>>>> ----------------------------------------
>>>>>>>> From: jay.krell at cornell.edu
>>>>>>>> To: m3devel at elegosoft.com
>>>>>>>> Date: Fri, 14 May 2010 09:08:58 +0000
>>>>>>>> Subject: Re: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>>>>>>>>
>>>>>>>>
>>>>>>>> Hm. Something is wrong on many platforms, in head, at least with my boot archives.
>>>>>>>> PPC_DARWIN, SOLsun, I386_LINUX
>>>>>>>> I'll figure it out. Hopefully soon.
>>>>>>>>
>>>>>>>> - Jay
>>>>>>>>
>>>>>>>> ----------------------------------------
>>>>>>>>> From: jay.krell at cornell.edu
>>>>>>>>> To: m3devel at elegosoft.com
>>>>>>>>> Date: Fri, 14 May 2010 06:37:07 +0000
>>>>>>>>> Subject: [M3devel] some other ports.. (PPC32_OPENBSD, SPARC64_OPENBSD, SPARC64_SOLARIS)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I've tried SPARC64_OPENBSD, SPARC64_SOLARIS, PPC32_OPENBSD recently (this week).
>>>>>>>>>
>>>>>>>>> SPARC64_SOLARIS gets far through RTLinker__InitRuntime, but ultimately bus errors in around the first line of RTType__UpdateCell, something in PolyBasis.
>>>>>>>>> The data in the assembly looks like. Maybe a runtime memory corruption.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> PPC32_OPENBSD complains something like in TextCat that a type is missing.
>>>>>>>>> I think it used to mostly work since I deleted some install I had there.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> SPARC64_OPENBSD bus errors just a few instructions into RTLinker__InitRuntime.
>>>>>>>>> (gdb) disassem
>>>>>>>>> Dump of assembler code for function RTLinker__InitRuntime:
>>>>>>>>> 0x00000000004bd01c : save %sp, -224, %sp
>>>>>>>>> 0x00000000004bd020 : sethi %hi(0xd18800), %l7
>>>>>>>>> 0x00000000004bd024 : add %l7, 0x1fc, %l7 ! 0xd189fc
>>>>>>>>> 0x00000000004bd028 : call 0x4bd010 <_m3_fault+60>
>>>>>>>>> 0x00000000004bd02c : nop
>>>>>>>>> 0x00000000004bd030 : stx %i0, [ %fp + 0x87f ]
>>>>>>>>> 0x00000000004bd034 : stx %i1, [ %fp + 0x887 ]
>>>>>>>>> 0x00000000004bd038 : stx %i2, [ %fp + 0x88f ]
>>>>>>>>> 0x00000000004bd03c : stx %i3, [ %fp + 0x897 ]
>>>>>>>>> 0x00000000004bd040 : sethi %hi(0x942c00), %g1
>>>>>>>>> 0x00000000004bd044 : or %g1, 0x290, %g1 ! 0x942e90
>>>>>>>>> 0x00000000004bd048 : ldx [ %l7 + %g1 ], %g1 << here
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> This seems like it'll be tough going. :(
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I think I'll try with PIC turned off.
>>>>>>>>>
>>>>>>>>> - Jay
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>
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