Re: [Valgrind-users] Illegal opcode in libX11 (SDL/OpenGL app)

[Josef W. <Jos...@gm...>]

On Monday 02 October 2006 19:40, Brad Fish wrote:
> vex x86->IR: unhandled instruction bytes: 0xDB 0x8D 0xF0 0xDB
> ==28501== valgrind: Unrecognised instruction at address 0x4390741.

Have you checked with Valgrind 3.2.1?
If you get the same problem, please rise a bug report for it.

> instruction. The only major change on my system since I ran valgrind on this
> app successfully a few months ago was my recent switch to GCC 4.1 from 3.4.
> My -march hasn't changed at all (prescott).

That seems to be the reason. The autovectorizer (for using the SIMD
instructions, ie. SSEx) in gcc improved a lot in GCC 4.0/1, so probably
GCC 3.4 never produced the above instruction.

Josef