Crash Signature Invariant

Sometimes there are crashes in multiplatform products where only some portion of Crash Signature (Volume 6, page 37) is similar, for example:

x86: cmp dword ptr [eax], 1
x64: cmp dword ptr [r10]. 1

One crash dump had the following condensed stack trace:

0: kd> kc
DriverA
win32k!DrvSetMonitorPowerState
win32k!xxxSysCommand
win32k!xxxRealDefWindowProc
win32k!NtUserfnNCDESTROY
win32k!NtUserMessageCall
nt!KiSystemServiceCopyEnd

With the following faulting instruction:

DriverA+0x1234:
cmp     dword ptr [r11],1 ds:002b:00000000`00000000=????????

A search for DriverA led to this x86 crash analyzed some time ago:

0: kd> kc
DriverA
nt!IopfCallDriver
win32k!GreDeviceIoControl
win32k!DrvSetMonitorPowerState
win32k!xxxSysCommand
win32k!xxxRealDefWindowProc
win32k!xxxWrapRealDefWindowProc
win32k!NtUserfnNCDESTROY
win32k!NtUserMessageCall
nt!KiSystemServicePostCall

0: kd> r
DtiverA+0x1423:
cmp     dword ptr [ecx],1    ds:0023:00000000=????????

We see common function names on both stack traces and overall flow is the same (only 3 functions are omitted in x64 trace); we see the same NULL pointer dereference for the same comparison instruction with the same comparison operand, #1.