Re: ICE on ARM

[Ethan M. <merritt@u.washington.edu>]

On Monday 03 May 2010, pl...@pi... wrote:
> Hi,
> 
> I'm trying to cross-compile gnuplot with maverick crunch fpu on ARM.
> 
> I have it building without the fpu code generation but it falls at the 
> first hurdle if I use the FPU.
> 
> CFLAGS="-O2 -mcpu=ep9312 -mfpu=maverick -mfloat-abi=softfp" 
> CXXFLAGS="-O2 -mcpu=ep9312 " ./configure --host=arm --prefix=/rar/root 
> --without-x --without-pdf --without-cairo --without-documentation 
> --disable-wxwidgets --without-lua --without-tutorial 
> --disable-volatile-data  --disable-objects
> 
> make

[...]
> arm-maverick-linux-gnueabi-gcc -DHAVE_CONFIG_H -I. -I..  -I../term 
> -I../term -DBINDIR=\"/rar/root/bin\" 
> -DX11_DRIVER_DIR=\"/rar/root/libexec/gnuplot/4.3\" 
                                              ^^^^^
So your source must be about a year old?  Without a precise date on the source
it's hard to comment on what pitfalls may lie in that routine.  On the other
hand, your compiler failure seems to come from the last line of the routine
so I'm not sure that more precise line numbers would help.

> -DGNUPLOT_PS_DIR=\"/rar/root/share/gnuplot/4.3/PostScript\" 
> -DGNUPLOT_JS_DIR=\"/rar/root/share/gnuplot/4.3/js\" 
> -DCONTACT=\"gnu...@li...\" 
> -DHELPFILE=\"/rar/root/share/gnuplot/4.3/gnuplot.gih\" 
> -DGNUPLOT_X11=\"`echo gnuplot_x11 | sed 's,x,x,'`\"   -O2 -mcpu=ep9312 
> -mfpu=maverick -mfloat-abi=softfp -MT axis.o -MD -MP -MF .deps/axis.Tpo 
> -c -o axis.o axis.c
> axis.c: In function 'gen_tics':
> axis.c:1163: internal compiler error: Segmentation fault
> Please submit a full bug report,
> 
> 
> gen_tics seems to make heavy use of floats , is there any areas that may 
> be a bit flakey on an unusual arch?

Have you tried with -O0 ?

> Clearly this is a major problem with the compiler itself but I'm 
> wondering if there's anything likely to trip it up.

The code tests for loss-of-precision errors that "shouldn't happen".
I can imagine that this might confuse a software fp library.
Somewhere around line 1068 you may see a code section that begins
   if (1) /* (some-test-for-range-and-or-step-size) */
You could try setting that to  if (0) instead, thus disabling the
tests for  (x + fabs(delta) <= x).