Alex, thanks for the hint. I'll have a look at TCG. Bye Chris.
On Feb 18, 2008 1:07 PM, Alexander Graf <[EMAIL PROTECTED]> wrote: > > On Feb 17, 2008, at 9:22 PM, Christian Roue wrote: > > > Well, I somehow felt like it was a bit brutal and probably fixing the > > symptoms which is apparently the case. > > Looking more carefully, compile fails in : > > sh4-linux-user for function op_cmp_str_T0_T1 > > gcc optimization leads to a ret followed by a last assignement with > > a jump back. > > I guess dyngen hopes to find function epilogue as the last bytes. > > It's apparently the only function where it happens. > > > > I found that adding gcc option "-fno-tree-dominator-opts" for sh4 > > target avoids this (I suppose) unwanted optimization. > > It may be a bit brutal again ( disabling too many optims or wrong > > ones). > > May be the op_cmp_str_T0_T1 function can be rewritten to something > > that avoids this optimization. > > Am I on a better track ? > > This looks like the right approach to the symptoms. The "real fix" > would be to move the sh4 target to TCG, but for the meantime I believe > this is the way to go. You can already find a lot of these > unoptimization flags autodetected in the configure script, so I guess > that'd be the right place for a patch. > > I am not sure if anybody with commit right listens, though. > > Regards, > > Alex > > > > > > > > Bye > > Chris. > > > > > > On Feb 16, 2008 9:01 PM, Paul Brook <[EMAIL PROTECTED]> wrote: > >> On Saturday 16 February 2008, Christian Roue wrote: > >>> Hi all, > >>> I tried to compile qemu cvs head on my x86_64 linux with gcc 4.1.2 > >>> using > >>> --disable-gcc-check, I found compile fails as stated in configure > >>> before i > >>> disabled gcc check.. > >>> Error message, points to a problem of dyngen not correctly detecting > >>> function ends on i386 when last instruction is a jump. I applied > >>> following > >>> change and successfully compiled/run qemu i386. This extra test > >>> check for > >>> a relative backward jump to function exit ret, > >>> gcc 4 apparently generates a few of these. > >> > >> You patch is wrong. The dyngen error is correct. > >> > >> Paul > >> > > > > > > > >
