but in case you want a few %% of extra emulation performance - it is still possible to disable it with configure option.
most guests I saw do not use it !
for CPU emulation performance reasons, the alignment check compilation
still can be enabled using configure option --enable-alignment-check.
There is no software in the world which enable #AC exception checking, this
x86 feature is completely legacy but its emulation support costs up to 3-5%
emulation speed.
The checking for #AC exception enable still will be done, if
CPL == 3, EFLAGS.AC = 1 and CR0.AM = 1
but the alignment check is not compiled in, the Bochs will PANIC with corresponding message.
You can press 'always continue' and ignore the PANIC, the simulation will continue as if alignment checking is not enabled.
The problem with Parity is it is generally referenced very rarely so the current lazy flags code is not efficient to updated Parify flag only (because it updates low 8 bits of .result value the existing Zero Flag has to be shadowed in .auxbits.
So I flipped it around, to make Parity be shadowed in auxbits. .result now is only needed to derive Zero Flag, and both Sign and Parify are derived from .result + .auxbits (as Zero Flag is now). For the 90% of the conditional jumps that are JZ or JNZ, this is a speedup.
Parity is now derived from 8 bits in .result and 8 bits in .auxbits, and Sign is derived from one flag in .result and 1 bit in .auxbits by XOR-ing them all together. It makes the code sequences for SAHF and POPF simpler too.
of the device specified in 'string'. Added register mechanism and chained
list to store the device name and pointer. Replace hardcoded debug info
implementations for pic, pci and vga by the new one.
- TODO #1: improve existing debug_dump() output and add more devices
- TODO #2: add support for additional arguments and replace the NE2k print_info()
- TODO:
add debug info for more devices without adding them to bx_devices_c and
without a macro in plugin. A register mechanism in the debugger code would
be nice. Currently it is only possible to show the devices state by
accessing the save/restore tree. The debug_dump() output should show
the operation mode and the most important registers.
on Windows. Added early command line check for this option to call the
console creation for sdl and wx only if required. NOTE: The console is still
needed for the config interface 'textconfig', the console debugger and log
output to stdout/stderr.
