[fpc-devel] According to Valgrind, something is wrong in IndexByte

Micha Nelissen micha at neli.hopto.org
Sat Aug 13 16:41:43 CEST 2005


On Sat, 13 Aug 2005 00:03:01 -0400
Jan Ruzicka <jan.ruzicka at comcast.net> wrote:

> On Aug 12, 2005, at 05:04, Micha Nelissen wrote:
> 
> > But if I use my own version (which I use for delphi and is i386 
> > specific), it reports no errors in this location, for 
> > Dbf_Common/Dbf_Memo.
> >
> > i386 IndexByte seems way more complex than my custom MemScan, but 
> > maybe that's necessary somehow.
>
> Have you investigated more into the Valgrind behavior?
> The jump (JNE     @@1) is reacting to "REPNE SCASB" and all values seem 
> to be defined.
> Valgrind may be expecting some numerical operation to set the flags.
> "Flags Affected: None; however, the CMPS and SCAS instructions do set 
> the status flags in the EFLAGS register."

Hmm is your point that valgrind should detect an error in my "REPNE SCASB" ? 

I am not familiar with the internals of valgrind, so to conclude from 1 hour valgrind-experience that valgrind is faulty would be a little over the top IMHO...

Micha




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