> Notice the 'repz mov' sequence, which seems to be undocumented > instruction. It seems to work somehow but chokes valgrind decoder. > The following patch (against current CVS) fixes this problem,
This patch is incorrect. It could match any number of other instructions that happen to end in 0xf3. eg 0: c7 45 00 00 00 00 f3 movl $0xf3000000,0x0(%ebp) 7: c3 ret IIRC the "rep; ret" sequence is to avoid a pipeline stall on Athlon CPUs. Try tuning for a different CPU. Paul > Index: dyngen.c > =================================================================== > RCS file: /cvsroot/qemu/qemu/dyngen.c,v > retrieving revision 1.40 > diff -u -r1.40 dyngen.c > --- dyngen.c 27 Apr 2005 19:55:58 -0000 1.40 > +++ dyngen.c 9 Nov 2005 19:12:38 -0000 > @@ -1387,6 +1387,12 @@ > error("empty code for %s", name); > if (p_end[-1] == 0xc3) { > len--; > + /* This can be 'rep ; ret' optimized return sequence, > + * need to check further and strip the 'rep' prefix > + */ > + if (len != 0 && p_end[-2] == 0xf3) { > + len--; > + } > } else { > error("ret or jmp expected at the end of %s", name); > } _______________________________________________ Qemu-devel mailing list Qemu-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/qemu-devel