Re: ilmbase

[Michael Schmitz <schmitz@zirkon.biophys.uni-duesseldorf.de>]

> > > results at
> > > <http://buildd.debian.org/fetch.cgi?&pkg=ilmbase&ver=1.0.1-2&arch=m68k&stamp=1208985766&file=log>
> >
> > Thanks - that gets a lot farther along. Different gcc and binutils,
> > though.
>
> Want me to try it with the same versions on aranym?

That's probably not worth it. Do you stil have the build tree?

objdump on testBitPatterns.o gives:


0000005c 
<_ZN63_GLOBAL__N_.._.._HalfTest_testBitPatterns.cpp_00000000_2E91A93413floatPosQNan1Ev>:
  5c:   4e56 0000       linkw %fp,#0
  60:   f23c 4400 7fff  fmoves #nan,%fp0
  66:   ffff
  68:   4e5e            unlk %fp
  6a:   4e75            rts

0000006c 
<_ZN63_GLOBAL__N_.._.._HalfTest_testBitPatterns.cpp_00000000_2E91A93413floatNegQNan1Ev>:
  6c:   4e56 0000       linkw %fp,#0
  70:   f23c 4400 7fff  fmoves #nan,%fp0
  76:   ffff
  78:   4e5e            unlk %fp
  7a:   4e75            rts

0000007c 
<_ZN63_GLOBAL__N_.._.._HalfTest_testBitPatterns.cpp_00000000_2E91A93413floatPosQNan2Ev>:
  7c:   4e56 0000       linkw %fp,#0
  80:   f23c 4400 7fff  fmoves #nan,%fp0
  86:   ffff
  88:   4e5e            unlk %fp
  8a:   4e75            rts

0000008c 
<_ZN63_GLOBAL__N_.._.._HalfTest_testBitPatterns.cpp_00000000_2E91A93413floatNegQNan2Ev>:
  8c:   4e56 0000       linkw %fp,#0
  90:   f23c 4400 7fff  fmoves #nan,%fp0
  96:   ffff
  98:   4e5e            unlk %fp
  9a:   4e75            rts

IOW, either binutils or cpp ignore the bit pattern bunged in the 
respective union, and replace it with a positive NaN straight away.

I'd like to see how that piece of code looks like when buils with other 
versions of gcc and/or cpp. gcc-4.3_4.3.0-3 g++-4.3_ binutils_2.18.1~cv
s20080103-1 is what I used.

I'll play with the respectice code some more, including trying -O1 or -O0. 
Other ideas, anyone?

Cheers,

	Michael