commit fb6a77ed78876083e8ba4c2f92384db5c2e41be8
Author: Mark Wielaard <mark@klomp.org>
Date:   Tue Feb 8 16:36:08 2022 +0100

    ppc64 --track-origins=yes failure because of bad cmov addHRegUse
    
    For Pin_CMov getRegUsage_PPCInstr called addHRegUse for the dst
    register with HRmWrite, but since this is a conditional move the
    register could be both read and written (read + write = modify).
    This matches the dst of Pin_FpCMov and Pin_AvCMov.
    
    In a very rare case, and only with --track-origins=yes, this
    could cause bad code generation.
    
    This is slightly amazing, this code is from 2005 and as far as
    I know we never seen an issue with --track-origins=yes on power
    before. And I have been unable to come up simple reproducer.
    
    https://bugs.kde.org/show_bug.cgi?id=449672

diff --git a/VEX/priv/host_ppc_defs.c b/VEX/priv/host_ppc_defs.c
index 3ae0f6e08..4222b4786 100644
--- a/VEX/priv/host_ppc_defs.c
+++ b/VEX/priv/host_ppc_defs.c
@@ -2590,7 +2590,7 @@ void getRegUsage_PPCInstr ( HRegUsage* u, const PPCInstr* i, Bool mode64 )
       return;
    case Pin_CMov:
       addRegUsage_PPCRI(u,  i->Pin.CMov.src);
-      addHRegUse(u, HRmWrite, i->Pin.CMov.dst);
+      addHRegUse(u, HRmModify, i->Pin.CMov.dst);
       return;
    case Pin_Load:
       addRegUsage_PPCAMode(u, i->Pin.Load.src);