Re: [Valgrind-users] Need test case for: REPE then 0xF: Unhandled REPE case

[Dominic M. <dma...@ai...>]

Here's a very short test program that produces this error for me.  I'm 
using a Pentium 3, though, not a Pentium 4.  The problem only happens if I 
use the -march=pentium3 option with gcc 3.x.

Test program:

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char **argv)
{
   float f = rand() / (float)RAND_MAX;
   printf("f=%f\n", f);

   return 0;
}

Compilation line:

  gcc -march=pentium3 foo.c

> gcc -v
Thread model: posix
gcc version 3.2

> valgrind --version
valgrind-1.9.4

I hope this helps!

- Dominic

---------------------------------------------------------------

From: Julian Seward <js...@ac...>
To: val...@li...
Date: Sun, 27 Apr 2003 00:13:43 +0100
Subject: [Valgrind-users] Need test case for: REPE then 0xF: Unhandled 
REPE
case


Hello.  I'm trying to put together bug fixes for 1.9.6.

Several people reported this panic:

   REPE then 0xF

   valgrind: the `impossible' happened:
      Unhandled REPE case

I'd like to fix it, since it seems to afflict quite a number
of people.  However, reading my Intel P4 documentation I can't
figure out what instruction this is.

So: does anyone have a smallish test case I can use to reproduce
this with?  Or (not so good, but it would be a help) can anyone
tell me what the byte after the 0xF is?  You can find out
by changing vg_to_ucode.c:4321 from

         VG_(printf)("REPE then 0x%x\n", (UInt)abyte);

to

         VG_(printf)("REPE then 0x%x 0x%x\n", (UInt)abyte,
                                              (UInt)getUChar(eip));

I prefer a test case tho, so I can test any fix I make.

Thanks,

J