Bug 495174

Summary: vex amd64->IR: unhandled instruction bytes: 0xC4 0xE3 0xF1 0xCE 0xC6 0x0 0xC5 0xF9 0xDB 0xC3 (vgf2p8affineqb)
Product: [Developer tools] valgrind Reporter: Sebastian Ramacher <sramacher>
Component: vexAssignee: Julian Seward <jseward>
Status: REPORTED ---    
Severity: normal CC: edwin.frank.loeffler, pjfloyd
Priority: NOR    
Version First Reported In: 3.23.0   
Target Milestone: ---   
Platform: Ubuntu   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Sebastian Ramacher 2024-10-22 08:03:36 UTC 
valgrind 3.23.0 does not handle GF2P8AFFINEQB instructions and errors out with

vex amd64->IR: unhandled instruction bytes: 0xC4 0xE3 0xF1 0xCE 0xC6 0x0 0xC5 0xF9 0xDB 0xC3

objdump -S output from location that causes the error:

  128b58:       c4 e3 f1 ce c6 00       vgf2p8affineqb $0x0,%xmm6,%xmm1,%xmm0
Comment 1 Paul Floyd 2024-10-22 09:21:42 UTC 
My guess is that we don’t support GFNI. Do we test for it with cpuid?
Comment 2 edwloef 2025-09-20 09:19:50 UTC 
I can confirm this to still be the case with valgrind 3.25.1:

vex amd64->IR: unhandled instruction bytes: 0xC4 0xE3 0xED 0xCE 0xD7 0x0 0xC4 0xE2 0x4D 0x0

objdump at that location: vgf2p8affineqb $0x0,%ymm7,%ymm2,%ymm2