Therefore I tried the floating point kernel-emulation in the linux kernel, which gives lots of warnings during compiling (see below 1.). After that, there is no illegal instruction anymore, but printf(%f,...) gives always 0.147484 (see 2.)
I am using OpenWrt with uClibc 0.9.28.2, Linux Kernel 2.6.22.1 together with a PowerPC 405 hard core in a Xilnix VirtexII Pro FPGA XC2VP30.
Is this a but in uClibc's soft-float AND/OR the kernels ppc/math-emu? What can I do to get fp-requiring applications running?
If this helps: when I try to run rrdtool, I also get an error about symbol 'rintf' (see 3.), although I compiled everything with option -fPIC.
CC arch/powerpc/math-emu/fadd.o
arch/powerpc/math-emu/fadd.c: In function 'fadd':
arch/powerpc/math-emu/fadd.c:31: warning: right shift count is negative
arch/powerpc/math-emu/fadd.c:31: warning: left shift count >= width of type
arch/powerpc/math-emu/fadd.c:13: warning: 'R_e' may be used uninitialized in this function
arch/powerpc/math-emu/fadd.c:13: warning: 'R_f1' may be used uninitialized in this function
arch/powerpc/math-emu/fadd.c:13: warning: 'R_f0' may be used uninitialized in this function
2.:
root@192:/# float-test
Test whether math-emulation works or not:
print double -5.5 = 0.147484 ?
print double 1.25 = 0.147484 ?
print double pi = 0.147484 ?
print float -5.5 = 0.147484 ?
print float 1.25 = 0.15 ?
print float pi = 0.147484 ?
pi=4*atan(1)= 0.147484 ?
If this is right, soft-float seems to work!
3.:
root@192:/# rrdtool
R_PPC_REL24: Compile shared libraries with -fPIC!
rrdtool: symbol 'rintf': can't handle reloc type 0xa in lib '/usr/lib/librrd.so.2'
float-test.c [^] (693 bytes) 09-05-07 00:54 
