Am Dienstag, 26. September 2006 22:23 schrieb Wolfgang Grandegger: > Niklaus Giger wrote: > > Am Dienstag, 26. September 2006 18:28 schrieb Wolfgang Grandegger: > >> Philippe Gerum wrote: > >>> On Tue, 2006-09-26 at 16:56 +0200, gilles.chanteperdrix wrote: > >> > >> OK, but in general, soft-float emulation should be used on systems > >> without FPU and this is even more important for real-time. This is a > >> tool chain issue. Niklaus, what tool chain are you using? > > > > In my .config I have > > MATH_EMULATION=y > > You seem to need that because your compiler generates code with hard FP > instructions. You could check this with: > > $ ppc-linux-objdump -d prog|egrep ":\s*[e-f]" This does not return any match on my system.
But looking at the disassembly of the latency program I have code like: 100081bc <_restfpr_28_x>: 100081bc: cb 8b ff e0 lfd f28,-32(r11) or 1000798c <__floatsidf>: 1000798c: 7c 08 02 a6 mflr r0 10007990: 2f 83 00 00 cmpwi cr7,r3,0 10007994: 94 21 ff c0 stwu r1,-64(r1) 10007998: 90 01 00 44 stw r0,68(r1) 1000799c: 54 60 0f fe rlwinm r0,r3,1,31,31 100079a0: 90 01 00 14 stw r0,20(r1) 100079a4: 40 9e 00 24 bne- cr7,100079c8 <__floatsidf+0x3c> > > The toolchain is gcc-3.4.4-glibc-2.3.5/powerpc-405-linux-gnu built using > > Dan Kegel crosstool (Version 0.42 if I remember exactly). > > > > Shall I switch to another one? > > The ELDK from DENX uses FP soft-emulation for 4xx (http://www.denx.de). > Choose v3.1.1 for Linux 2.4 and v4 for Linux 2.6. I am breathing only PowerPC code on my Mac PowerBook (running Debian) and never managed to installed ELDK on it. (And even Detlev as a Debian developer couldn't recommend a simple way.) But I assume that I specifying GLIBC_EXTRA_CONFIG="--without-fp" in the powerpc-405.dat should be enough to make Dan Kegels crosstool emit Soft-FPU emulation. I will try to run the tests at work where I have installed ELDK 4.0, but not yet a fully working environment. Therefore it may take some time to report a result back. -- Niklaus Giger _______________________________________________ Xenomai-core mailing list [email protected] https://mail.gna.org/listinfo/xenomai-core
