Starting convergence to new lazy flags scheme by Darek Mihocka (www.emulators.com). The new flags code is still being validated and perfected but I try to minimize the diff between 2 versionS
Averything that required cpu.h include now has it explicitly and there are a lot of files not dependant by CPU at all which will compile a lot faster now ...
1. Review and commit patch
[ 896733 ] Lazy flags, for more instructions, only 1 src op
May be partially, but I hope to get all ideas from patch in
2. Get Bochs speedup after lazy flags optimization
3. Most important for me: improve correctness of emulation by handling several
undocumented EFLAGS modifications. And finally pass
UFLAGS - Undefined Flags Test v 3.0
Copyright (C) Potemkin's Hackers Group (PHG) 1989,1995
The test still fails on > 50% of its checks.
there to offer a way to substitute more efficient code
to do the RMW cases. At the moment, they just map to
the normal functions.
Sorry, restored the previous version ...
"bx_bool" which is always defined as Bit32u on all platforms. In Carbon
specific code, Boolean is still used because the Carbon header files
define it to unsigned char.
- this fixes bug [ 623152 ] MacOSX: Triple Exception Booting win95.
The bug was that some code in Bochs depends on Boolean to be a
32 bit value. (This should be fixed, but I don't know all the places
where it needs to be fixed yet.) Because Carbon defined Boolean as
an unsigned char, Bochs just followed along and used the unsigned char
definition to avoid compile problems. This exposed the dependency
on 32 bit Boolean on MacOS X only and led to major simulation problems,
that could only be reproduced and debugged on that platform.
- On the mailing list we debated whether to make all Booleans into "bool" or
our own type. I chose bx_bool for several reasons.
1. Unlike C++'s bool, we can guarantee that bx_bool is the same size on all
platforms, which makes it much less likely to have more platform-specific
simulation differences in the future. (I spent hours on a borrowed
MacOSX machine chasing bug 618388 before discovering that different sized
Booleans were the problem, and I don't want to repeat that.)
2. We still have at least one dependency on 32 bit Booleans which must be
fixed some time, but I don't want to risk introducing new bugs into the
simulation just before the 2.0 release.
Modified Files:
bochs.h config.h.in gdbstub.cc logio.cc main.cc pc_system.cc
pc_system.h plugin.cc plugin.h bios/rombios.c cpu/apic.cc
cpu/arith16.cc cpu/arith32.cc cpu/arith64.cc cpu/arith8.cc
cpu/cpu.cc cpu/cpu.h cpu/ctrl_xfer16.cc cpu/ctrl_xfer32.cc
cpu/ctrl_xfer64.cc cpu/data_xfer16.cc cpu/data_xfer32.cc
cpu/data_xfer64.cc cpu/debugstuff.cc cpu/exception.cc
cpu/fetchdecode.cc cpu/flag_ctrl_pro.cc cpu/init.cc
cpu/io_pro.cc cpu/lazy_flags.cc cpu/lazy_flags.h cpu/mult16.cc
cpu/mult32.cc cpu/mult64.cc cpu/mult8.cc cpu/paging.cc
cpu/proc_ctrl.cc cpu/segment_ctrl_pro.cc cpu/stack_pro.cc
cpu/tasking.cc debug/dbg_main.cc debug/debug.h debug/sim2.cc
disasm/dis_decode.cc disasm/disasm.h doc/docbook/Makefile
docs-html/cosimulation.html fpu/wmFPUemu_glue.cc
gui/amigaos.cc gui/beos.cc gui/carbon.cc gui/gui.cc gui/gui.h
gui/keymap.cc gui/keymap.h gui/macintosh.cc gui/nogui.cc
gui/rfb.cc gui/sdl.cc gui/siminterface.cc gui/siminterface.h
gui/term.cc gui/win32.cc gui/wx.cc gui/wxmain.cc gui/wxmain.h
gui/x.cc instrument/example0/instrument.cc
instrument/example0/instrument.h
instrument/example1/instrument.cc
instrument/example1/instrument.h
instrument/stubs/instrument.cc instrument/stubs/instrument.h
iodev/cdrom.cc iodev/cdrom.h iodev/cdrom_osx.cc iodev/cmos.cc
iodev/devices.cc iodev/dma.cc iodev/dma.h iodev/eth_arpback.cc
iodev/eth_packetmaker.cc iodev/eth_packetmaker.h
iodev/floppy.cc iodev/floppy.h iodev/guest2host.h
iodev/harddrv.cc iodev/harddrv.h iodev/ioapic.cc
iodev/ioapic.h iodev/iodebug.cc iodev/iodev.h
iodev/keyboard.cc iodev/keyboard.h iodev/ne2k.h
iodev/parallel.h iodev/pci.cc iodev/pci.h iodev/pic.h
iodev/pit.cc iodev/pit.h iodev/pit_wrap.cc iodev/pit_wrap.h
iodev/sb16.cc iodev/sb16.h iodev/serial.cc iodev/serial.h
iodev/vga.cc iodev/vga.h memory/memory.h memory/misc_mem.cc
into inline functions with asm() statements in cpu.h. This cleans
up the *.cc code (which now doesn't have any asm()s in it), and
centralizes the asm() code so constraints can be modified in one
place. This also makes it easier to cover more instructions
with asm()s for more efficient eflags handling.
coverage of the high-frequency eflags instructions. That should
complete the asm() eflags updates for now, as we should be stabilizing
moving towards bochs 2.0.
all available optimizations in one shot.
Finished one last case of an instruction which could but didn't use
the Read-Modify-Write variants of access.cc functions.
Started going through the integer instructions, merging obvious cases
where there are two "if (modrm==11b) {" clauses and very little
action in between, and cleaning up the aweful indentation leftover
from many years ago when those instructions were implemented using
cut-and-paste. We may get a little extra performance out of these
mods, but they'll also be easier after I'm finished to enhance
with asm() statements to knock out the lazy flags processing on x86.
were simply replacements of the eflags mask constants with
the macro names already in cpu.h for asm() statements. I forgot
to use the macros for some instructions.
0x000008d5 -> EFlagsOSZAPCMask
0x000008d4 -> EFlagsOSZAPMask
use getB_CF() etc. getB_CF() and friends are only for a relatively
small number of cases where a true boolean/binary number (0 or 1) is required
rather than 0 or non-0 as is returned by get_CF().
user can turn on/off use of native host specific inline asm
statements. By default, this option is enabled, so you only
need it to disable inline asms in your compile for now.
Currently only on x86+GCC environments, will inline asm()
statements be used. Eventually, other platforms could specify
some asm()s; probably for endian issues such as byte-swapping
and unaligned memory accesses. On x86, there are some inline
asm()s which do the arithmetic EFLAGS processing so that the
lazy flags handling is somewhat bypassed. Eventually, I'll
add more, at least for the more common instructions. This
adds a little extra performance.
of (1 & (val32>>N)), and added a getB_?F() accessor for special
cases which need a strict binary value (exactly 0 or 1). Most
code only needed a value for logical comparison. I modified the
special cases which do need a binary number for shifting and
comparison between flags, to use the special getB_?F() accessor.
Cleaned up memory.cc functions a little, now that all accesses
are within a single page.
Fixed a (not very likely encountered) bug in fetchdecode.cc (and
fetchdecode64.cc) where a 2-byte opcode starting with a prefix
starts at the last offset on a page. There were no checks
on the segment overrides for a boundary condition. I added them.
The eflags enhancements added just a tiny bit of performance.
so frequently.
Coded asm() statements for INC/DEC_ERX() instructions.
Cleaned up the iCache a litle including a bug fix. The
generation ID was decrementing the whole field including
some high meta bits. That could roll over after 1 Billion
cycles. I know only decrement if the field is valid, to
save the write.
I implemented inline functions which can serve the value of
the arithmetic flags if they are cached, and redirect to
the lazy_flags.cc routines if not.
Most of this was just prep work for adding more asm() statements
for native eflags processing when on x86.
