Bug 495174 - vex amd64->IR: unhandled instruction bytes: 0xC4 0xE3 0xF1 0xCE 0xC6 0x0 0xC5 0xF9 0xDB 0xC3 (vgf2p8affineqb)
Summary: vex amd64->IR: unhandled instruction bytes: 0xC4 0xE3 0xF1 0xCE 0xC6 0x0 0xC5...
Status: REPORTED
Alias: None
Product: valgrind
Classification: Developer tools
Component: vex (other bugs)
Version First Reported In: 3.23.0
Platform: Ubuntu Linux
: NOR normal
Target Milestone: ---
Assignee: Julian Seward
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2024-10-22 08:03 UTC by Sebastian Ramacher
Modified: 2025-09-20 09:19 UTC (History)
2 users (show)

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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