Use "logical" since the functions deal with multiple bits instead of a single boolean value and because the 601 manual calls them Logical Instructions.
Use "ppc" for the enums because logical_and is defined elsewhere and because the original DPPC code used these names for those functions.
Add MPC601 variants. Variants that decrement and test the ctr are invalid bon't don't appear to trigger an exception. The manual says MPC601 can decrement the counter. Other CPUs do not decrement the counter but will branch based on the value.
Typing Control-C in Terminal app causes an interrupt signal that should enter the DPPC debugger but this only worked once since the signal handler never returned. Even if the signal handler reenabled the signal somehow, it calls enter_debugger recursively which is strange since the earlier calls to enter_debugger would never return.
Now the signal handler just sets a flag (power_on) which can be used to exit any loop (emulator loops, stepping loops, disassembly loops, dumping loops).
Main always calls enter_debugger now which calls the ppc_exec loop. The power_on flag will exit the ppc_exec loop to return to the debugger. Recursion of enter_debugger is eliminated except for calls to loguru's ABORT_F.
An enum power_off_reason is used to indicate why the power_on flag is set to false and to determine what happens next.
The `SubOpcode31Grabber[1024] = { ppc_illegalop }` initializer only
populates the first entry with ppc_illegalop (at least on some compilers),
switch to explicitly initializing the entire array with std::fill_n.
Also fix a couple of sign and overflow issues flagged by the Xcode
undefined behavior sanitizer.
Result of running IWYU (https://include-what-you-use.org/) and
applying most of the suggestions about unncessary includes and
forward declarations.
Was motivated by observing that <thread> was being included in
ppcopcodes.cpp even though it was unused (found while researching
the use of threads), but seems generally good to help with build
times and correctness.
While booting Mac OS X 10.2 installer CD, a return from RFI didn't change the instruction address virtual memory page but did change the physical memory page so we must always recalculate the physical address after RFI.
Perhaps there are other cases where this may be required?
- Subtract one so that it can't overflow to zero.
- Use page_start as the base so mask operation is not required.
- Recalculate it only when the page changes.
