This moves the scan thread logic and variables into a separate
ScanThread class. By turning ScanThread instances into members of the
most derived class, this ensures that the scan thread is always
properly stopped when the most derived class is destructed and fixes
a race condition that could cause the scan thread to call virtual
member functions from a derived class whose members have already
been destructed.
A drawback of this approach is that the scan thread must be the last
member variable, so this commit also adds static assertions to ensure
that the assumption stays valid.
When I first made VolumeVerifier, I figured that the distinction
between an unsigned ticket and an unsigned TMD was a technical
detail that users would have no reason to care about. However,
while this might be true for discs, it isn't equally true for
WADs, due to the widespread practice of fakesigning tickets to
set the console ID to 0. This practice does not require
fakesigning the TMD (though apparently people do it anyway,
at least sometimes...), and the presence of a correctly signed
TMD is a useful indicator that the contents have not been
tampered with, even if the ticket isn't correctly signed.
FCVT doesn't necessarily round to zero, so the result
might be inaccurate if we use it. To ensure correct
rounding, we use FCVTS from double FPR to 32-bit GPR.
Unfortunately, FCVTS can't do double FPR to single FPR.
This is now unused. Seems like it was an improper fix
(there would be a race if saving the screenshot took longer
than 2 seconds) back when it was used too.
The intent here is to generate a more compact instruction if a 32-bit
immediate can be zero-extended to the desired 64-bit immediate.
Nowadays the emitter is smart enough to do this for us, so this logic is
redundant.
There's no need to load the 64-bit immediate into a temporary register.
x64 will sign-extend 32-bit immediates to 64 bits, giving us the exact
value we need in this case.
48 C7 C0 00 00 FF FF mov rax,0FFFFFFFFFFFF0000h
48 21 C2 and rdx,rax
48 81 E2 00 00 FF FF and rdx,0FFFFFFFFFFFF0000h
- LEA is a bit silly when the source and the destination are the same. A
simple ADD or SHL will do in those cases.
66 8D 04 45 00 00 00 00 lea ax,[rax*2]
66 03 C0 add ax,ax
48 8D 04 00 lea rax,[rax+rax]
48 03 C0 add rax,rax
66 8D 14 D5 00 00 00 00 lea dx,[rdx*8]
66 C1 E2 03 shl dx,3
- When scaling by 2, consider summing the register with itself instead.
The former always needs a 32-bit displacement, so the sum is more
compact.
66 8D 14 45 00 00 00 00 lea dx,[rax*2]
66 8D 14 00 lea dx,[rax+rax]
Léo Lam