Bug 448026 - unhandled instruction bytes: 0x8F 0x6A 0x78 0x10 0xC8 0x4 0x4 0x0 0x0 0xC1
Summary: unhandled instruction bytes: 0x8F 0x6A 0x78 0x10 0xC8 0x4 0x4 0x0 0x0 0xC1
Status: RESOLVED DUPLICATE of bug 381819
Alias: None
Product: valgrind
Classification: Developer tools
Component: vex (show other bugs)
Version: 3.19 GIT
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: Julian Seward
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-01-06 15:32 UTC by dcb314
Modified: 2023-10-15 20:58 UTC (History)
2 users (show)

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Description dcb314 2022-01-06 15:32:10 UTC 
More detail:

vex amd64->IR: unhandled instruction bytes: 0x8F 0x6A 0x78 0x10 0xC8 0x4 0x4 0x0 0x0 0xC1
vex amd64->IR:   REX=0 REX.W=0 REX.R=0 REX.X=0 REX.B=0
vex amd64->IR:   VEX=0 VEX.L=0 VEX.nVVVV=0x0 ESC=NONE
vex amd64->IR:   PFX.66=0 PFX.F2=0 PFX.F3=0

This is from today's valgrind trunk.
Comment 1 Paul Floyd 2022-09-26 08:54:20 UTC 
A quick online disasm says that this is a bit extract opcode.

Can you provide a small reproducer?
Comment 2 dcb314 2022-09-26 09:59:29 UTC 
(In reply to Paul Floyd from comment #1)
> A quick online disasm says that this is a bit extract opcode.

Righto.

> Can you provide a small reproducer?

Sadly no. Not this many months later. 

I suspect it wouldn't be too hard to construct an artificial example in C which contains that opcode.
Comment 3 Mark Wielaard 2023-10-15 20:58:00 UTC 
This is BEXTR, Bit field extract (with register), part of BMI1

*** This bug has been marked as a duplicate of bug 381819 ***