Bug 154323

Summary: (wine) vex x86->IR: unhandled instruction bytes: 0xF2 0xEB 0xF5 0xEB
Product: [Developer tools] valgrind Reporter: Dan Kegel <dank>
Component: vexAssignee: Julian Seward <jseward>
Status: REPORTED ---    
Severity: crash CC: njn, tom
Priority: NOR    
Version: 3.2.3   
Target Milestone: ---   
Platform: Compiled Sources   
OS: Linux   
Latest Commit: Version Fixed In:
Bug Depends on:    
Bug Blocks: 256630    

Description Dan Kegel 2007-12-19 15:48:15 UTC
Version:           3.2.3 (using KDE Devel)
Installed from:    Compiled sources
Compiler:          gcc-4.1.2 
OS:                Linux

On Ubuntu Feisty, using a valgrind-3.2.3 built per
http://wiki.winehq.org/Wine_and_Valgrind,
I get
vex x86->IR: unhandled instruction bytes: 0xF2 0xEB 0xF5 0xEB
fairly early while valgrinding Dragon Naturally Speaking 8
(see http://bugs.winehq.org/show_bug.cgi?id=10726 for
how to install that under Wine).
Comment 1 Tom Hughes 2007-12-19 16:02:42 UTC
0xF2 0xEB appears to be REPNE JMP Jb which sounds like nonsense?
Comment 2 Julian Seward 2007-12-19 18:53:06 UTC
> ------- Additional Comments From tom compton nu  2007-12-19 16:02 -------
> 0xF2 0xEB appears to be REPNE JMP Jb which sounds like nonsense?


Could the F2 be a branch direction hint?  Or alternatively, it is 
redundant and hardware implementations just ignore it.
Comment 3 Tom Hughes 2011-08-11 12:29:20 UTC
The branch direction hints are 0x2E and 0x3E so this still seems like nonsense to me. Certainly I can't see anything in the Intel manuals that this would correspond to.