Bug 441843 - vex amd64->IR: unhandled instruction bytes: 0x48 0xF 0xFC 0xD 0x7 0xBF 0x3E 0x0 0xF 0x70
Summary: vex amd64->IR: unhandled instruction bytes: 0x48 0xF 0xFC 0xD 0x7 0xBF 0x3E 0...
Status: REPORTED
Alias: None
Product: valgrind
Classification: Developer tools
Component: vex (show other bugs)
Version: unspecified
Platform: Other Linux
: NOR crash
Target Milestone: ---
Assignee: Julian Seward
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2021-09-01 06:18 UTC by Julien Jorge
Modified: 2021-09-01 07:25 UTC (History)
2 users (show)

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Description Julien Jorge 2021-09-01 06:18:57 UTC 
When running my program with Valgrind & memcheck, it fails with an unhandled instruction message:

    vex amd64->IR: unhandled instruction bytes: 0x48 0xF 0xFC 0xD 0x7 0xBF 0x3E 0x0 0xF 0x70
    vex amd64->IR:   REX=1 REX.W=1 REX.R=0 REX.X=0 REX.B=0
    vex amd64->IR:   VEX=0 VEX.L=0 VEX.nVVVV=0x0 ESC=0F
    vex amd64->IR:   PFX.66=0 PFX.F2=0 PFX.F3=0
    ==2678158== valgrind: Unrecognised instruction at address 0xd000b1.
    ==2678158==    at 0xD000B1: ???
    ==2678158==    by 0xD0AF05: y8_ippiFilterDeblockingLuma_VerEdge_H264_8u_C1IR

It occurs with Valgrind 3.17 built from source on Centos 7.4. My program uses ipp 8.1.1.
Comment 1 Tom Hughes 2021-09-01 07:25:08 UTC 
This is a paddb instruction but operating on the 64 bit MMX registers which we don't appear to support.

We do support it with an 0x66 prefix (which causes it to operate on 128 bit SSE registers) and with a VEX prefix operating on either 128 or 256 bit registers.