FTBFS on armel: error: unable to find a register to spill in class 'VFP_LO_REGS'

[Stefano Rivera]

vtk 5.6.1-6ubuntu2 failed to build on armel with GCC 4.6.0-14ubuntu1. It's a no-change rebuild of 5.6.1-6ubuntu1 which build successfully with GCC
4.6.0-10ubuntu2.

Full build log: https://launchpadlibrarian.net/74326600/buildlog_ubuntu-oneiric-armel.vtk_5.6.1-6ubuntu2_FAILEDTOBUILD.txt.gz

[ 27%] Building CXX object Imaging/CMakeFiles/vtkImaging.dir/vtkImageQuantizeRGBToIndex.cxx.o
/build/buildd/vtk-5.6.1/Imaging/vtkImageQuantizeRGBToIndex.cxx: In function 'void vtkImageQuantizeRGBToIndexHistogram(T*, int*, vtkIdType*, int, int*, int**) [with T = double, vtkIdType = int]':
/build/buildd/vtk-5.6.1/Imaging/vtkImageQuantizeRGBToIndex.cxx:220:1: error: unable to find a register to spill in class 'VFP_LO_REGS'
/build/buildd/vtk-5.6.1/Imaging/vtkImageQuantizeRGBToIndex.cxx:220:1: error: this is the insn:
(insn 189 201 181 17 (set (subreg:SI (reg:QI 409) 0)
        (unsigned_fix:SI (fix:DF (reg:DF 73 s10 [orig:206 D.41537 ] [206])))) /build/buildd/vtk-5.6.1/Imaging/vtkImageQuantizeRGBToIndex.cxx:182 671 {fixuns_truncdfsi2}
     (expr_list:REG_DEAD (reg:DF 73 s10 [orig:206 D.41537 ] [206])
        (nil)))
/build/buildd/vtk-5.6.1/Imaging/vtkImageQuantizeRGBToIndex.cxx:220: confused by earlier errors, bailing out
make[3]: *** [Imaging/CMakeFiles/vtkImaging.dir/vtkImageQuantizeRGBToIndex.cxx.o] Error 1

[Jani Monoses (jani)]

Another package affected
https://launchpad.net/ubuntu/+source/libkdcraw/4:4.6.90+repack1-0ubuntu1/+build/2616014

[Michael Hope (michaelh1)]

Thank you for the bug report. Could you provide the following information so that we can reproduce the fault?
 * The command line that shows the fault
 * Preprocessed source of the failing file

To generate the preprocessed source, add '-save-temps' to the GCC command line. This will produce a .i file that you can compress and attach to this ticket.

I suspect this is the same as LP: #807573.

[Stefano Rivera (stefanor)]

>Could you provide the following information so that we can reproduce the fault?

 Sorry, I'm afraid I can't do that. I don't have a physical ARM box, and this package won't play ball under qemu.

[Michael Hope (michaelh1)]

OK. Let's see if the fix to LP: #807573 also fixes this problem and go from there.

[Ricardo Salveti (rsalveti)]

Fixed with with the workaround: adding -mfloat-abi=soft on armel

[Jani Monoses (jani)]

Also sauerbraten
https://launchpadlibrarian.net/74025533/buildlog_ubuntu-oneiric-armel.sauerbraten_0.0.20100728.dfsg%2Brepack-1_FAILEDTOBUILD.txt.gz

[Matthias Klose (doko)]

sauerbraten built

[Matthias Klose (doko)]

gcc-4.6 fixed

[Matthias Klose (doko)]

vtk built

[Michael Collison (michael-collison)]

Test case not provided to reproduce.