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: cb 8b ff e0 lfd f28,-32(r11)
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
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
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