79668 - 'Illegal instruction' when running a nightly build on a AMD-K6

Status: VERIFIED FIXED

(SeaMonkey :: Build Config, defect)

Description

[Jip de Bugzilla]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux 2.4.1 i586; en-US; rv:0.9) Gecko/20010504
BuildID:    20010508

After changing my cpu from a IBM 686MX to a AMD-K6,
mozilla nightly builds die with a 
 run-mozilla.sh: line 72: 17745 Illegal instruction
 $prog ${1+"$@"}

Nightly build 2001050405 runs fine.


Reproducible: Always
Steps to Reproduce:
1.install a AMD K6 533MHz
2.run mozilla
3.see it crashing

Actual Results:  run-mozilla.sh: line 72: 17801 Illegal instruction     $prog
${1+"$@"}


 $ cat /proc/cpuinfo 
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 5
model           : 8
model name      : AMD-K6(tm) 3D processor
stepping        : 12
cpu MHz         : 533.365
cache size      : 64 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr mce cx8 pge mmx syscall 3dnow k6_mtrr
bogomips        : 1064.96

Comment 1

[cls]

Hrm.  Not sure what's going on here.  The compiler upgrade on the nightly box
happened the afternoon of 20010503 so if that was the cause then it should have
mainfest in the 8pm build.  pip, what is the first build that you see the
problem with?

Comment 2

[Jip de Bugzilla]

Strange, the mozilla-i686-pc-linux-gnu.tar.gz I got, 
is 9404923 bytes big and says its a 2001050405 build,
is not the same as
/pub/mozilla/nightly/2001-05-04-05-trunk/mozilla-i686-pc-linux-gnu.tar.gz
(9530733 bytes)

Some more datapoints:

/pub/mozilla/nightly/2001-05-03-21-trunk/mozilla-i686-pc-linux-gnu.tar.gz
illegal instruction

/pub/mozilla/nightly/2001-05-04-05-trunk/mozilla-i686-pc-linux-gnu.tar.gz
illegal instruction

/pub/mozilla/nightly/2001-05-03-18-trunk/mozilla-i686-pc-linux-gnu.tar.gz
illegal instruction

/pub/mozilla/nightly/latest-xpcdom/xpcdom-linux-opt.tgz
ok

/pub/mozilla/nightly/2001-05-09-07-trunk/mozilla-i686-pc-linux-gnu.tar.gz
illegal instruction

/pub/mozilla/releases/mozilla0.9/mozilla-i686-pc-linux-gnu-0.9.tar.gz
size: 9404787 05/05/01 10:53:00 pm
ok

Comment 3

[cls]

Can you run any builds previous to 2001-05-03?  Looking at the asm comments from
both gcc 2.95.3 & egcs -fverbose-asm compiles, they both appear to be using
-mcpu=i386 -march=pentium which means that they both will use i586 specific
opcodes.  So in theory, if it didn't run with one, it wouldn't run with the
other.  

Granrose, I think we've hit this particular issue at least once before.  

Comment 4

[Jip de Bugzilla]

All mozilla-i686-pc-linux-gnu.tar.gz except where noted.

2001043014 ok
2001050221 ok
2001050305 ok
2001050308 ok
2001050309 (mozilla-gcc295-i686-pc-linux-gnu.tar.gz) illegal instruction
2001050314 ok
2001050318 illegal instruction
2001050321 illegal instruction

I installed my AMD K6 533 (and doubled my RAM from 128 to 256MB)
on may 30 2001 so I haven't got any experience with this bug and
configuration before that time.

Comment 5

[Jip de Bugzilla]

2001050910 ok
2001050914 ok
2001050921 ok

Comment 6

[cls]

Ok, so somehow the new compiler is generating code that doesn't work on AMD even
though it appears to only be using -mpentium.  :-/  Hrm.  Something to look into
later.  For now, the compiler has been removed from the build machine.

Comment 7

[Jon Granrose]

verified.

Comment 8

[Jip de Bugzilla]

Problem returned somewhere between 7 and 14 september. 

Comment 9

[cls]

WFM.  I'm posting this from my K6 box.  Are you sure you didn't grab one of the
gcc295 builds by mistake?

[mozilla]$ cat /proc/cpuinfo 
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 5
model           : 8
model name      : AMD-K6(tm) 3D processor
stepping        : 12

Comment 10

[Jip de Bugzilla]

Sorry, got confused because of an unrelated problem, and an old core file.

Comment 11

[Tracy Walker [:tracy]]

verified per reporters comments