stack limits. This is needed for EROS, and probably for L4, as both
rely on this SS fault (and the corresponding GP fault) to trigger the
switch from small address spaces to large address spaces. The
push_16() code was already correct, and I find the inconsistency a bit
odd.
I'm not 100% sure about the push_64() change, so I made the change
with a comment but left it a BX_PANIC() rather than switching it to
BX_INFO. I'll ask Peter momentarily to have a look and let me know.
While I was added, changed the push_16() BX_INFO message to be
consistent with the others -- all now say 'push outside stack limits'.
- Now compiles for plain ia-32
- Fixed some printf formatting for ia32 only.
- Update to latest Win32 DLL
- Added an ICEBP (Undoc 0xF8, INT 01) facility.
- updated to use latest VGA refresh routine
a control panel, but now we're calling it a text configuration interface.
Modified:
.bochsrc Makefile.in bochs.h main.cc cpu/Makefile.in
debug/Makefile.in disasm/Makefile.in fpu/Makefile.in
gui/Makefile.in iodev/Makefile.in memory/Makefile.in
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
bx_shadow_num_c able to handle pointers to 64 bit values. This
allows x86-64 and wxWindows to coexist.
- I had a number of duplicate constructors for bx_shadow_num_c,
with an without the description arg. I eliminated the ones
that had no description, and also removed the min/max arg from
all. I still need a bunch of constructors though, for
Bit64u*, Bit64s*, Bit32u*, Bit32s*, Bit16u*, Bit16s*, Bit8u*, Bit8s*.
Having all these constructors allows us to write
new bx_shadow_num (bxid, name, description, &value)
for basically any integer variable. They are all handled by the same class.
- these changes led to minor touchups in cpu/init.cc and iodev/keyboard.cc
- modified:
configure main.cc cpu/init.cc iodev/keyboard.cc
gui/siminterface.cc gui/siminterface.h
SSE/SSE2 for Stanislav. Also, some method prototypes and
skeletal functions in access.cc for read/write double quadword
features.
Also cleaned up one warning in protect_ctrl.cc for non-64 bit compiles.
There was an unused variable, only used for 64-bit.
This is an interim update to allow others to test.
We have userland code running!!! (up to a point)
Able to start executing "sash" as /sbin/init in userland from linux 64 bit
kernel until it crashes trying to access a null pointer. No kernel panics
though, just a segfault loop.
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.
hack with longjmp() back to cpu.cc main decode loop, and added a
check in there to return control when bx_guard.special_unwind_stack
is set (compiling with debugger enabled only).
If in the debugger you try to execute further instructions
(which you shouldn't), other fields need to be reset I would
think, such as EXT and errorno, and have to make sure ESP/EIP
are corrected properly. Basically, this hack is only good
for examining the current situation of a nasty fault.
to give the compiler some hints:
BX_CPP_AttrPrintf(formatArg, firstArg)
BX_CPP_AttrNoReturn()
The first is to tell the compiler that a function receives printf-like
arguments so it can do some smart argument checking w.r.t. the
format string. The 2nd tells the compiler that the function does
not ever return; it's not used yet, but I'd like to use it on
exception() after we fix the situation of it returning for debugging.
I fixed one parameter mismatch in cpu/ by deleting a deprecated
debug print statement. There are several other mismatches in
other code modules.
exit out of cpu_loop() and back to the caller can be honored.
Previously, code in this function was a part of cpu_loop so
a "return;" would already do that. Now, a value is passed
back to cpu_loop() to denote such a request, and then a return
is executed from cpu_loop().
I haven't tested this yet, but previously I must have broke
certain debugging requests by moving the code to a separate
function and not fixing the "return;" statements.
Symptom: Linux kernel 2.4.19 would hang in random places. CPU still
running, but in dle loop.
Cause: if APIC interrupt occurred while a PIC interrupt was pending, the
PIC interrupt would be lost. This is because either an APIC or PIC
interrupt would trash any pending interrupt event because INTR is only a state,
not an event queue.
Temporary fix: reworked apic.cc to have it's own copy of INTR state. cpu.cc now
checks for both cpu.INTR and local_apic.INTR.
Need to do further research to see if local_apic and pic can be integrated in such
a way as properly manage the combined effects of both devices accessing INTR state.
value and a change-mask, rather than passing all the boolean
change flags as arguments.
Recoded the POPF instruction in flag_ctrl.cc to use the
new writeEFlags() function, and to make it more sane.
Also, the old write_flags() and write_eflags() functions
redirect to writeEFlags() for now. Later, when we get
back in a development mode, it would be better to make
all calls use the new function and get rid of the old ones.
been using the Boolean type for a number of multi-bit fields on the
assumption that it is actually many bits wide. However, this assumption is
unsafe and has caused some bugs that are hard to track down.
- in the Carbon library on MacOS X, Boolean is defined to be an unsigned char.
This has been causing some of the EFLAGS accessors to fail (bits 8-31)
because they depended on Boolean being 32 bits wide. I changed these
accessors to return Bit32u instead. I believe that this will finally fix
[ 618388 ] Unable to boot under MacOS X.
- It would be possible to create a bochs specific type for booleans (bx_bool),
but it's cleaner to simply use "Boolean" when we actually mean a 1-bit true
or false field, and Bit8u/Bit32u when it is a multibit field.
32-bits rather than 64. This is possible, because there is
always an active null (heartbeat) timer, with periodicity
of less than or equal to the maximum 32-bit int value.
This generates a little less code in the hot part of cpu_loop,
and saved about 3% execution time on a Win95 boot.
Moved the asynchronous handling code from cpu_loop() to its
own function since it's a long path. This neatened up the
code a little (less gotos and all), and made it more clear
to use a "while (1)" around the iterative code in cpu_loop().
so that windows types can be used in fields, for example in cdrom.h:
#ifdef WIN32
HANDLE cdrom_interface::hFile;
#endif
- since every file includes bochs.h, I removed includes of <windows.h>
everywhere else
- modified: bochs.h cpu/extdb.cc gui/win32.cc gui/wx.cc iodev/cdrom.cc
iodev/eth_win32.cc iodev/floppy.cc
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.
These seem to be working better, are a more simple design,
easier to understand, and AFAIK don't have race conditions
in them like the old ones do.
Re-coded the apic timer, to return cycle accurate values
which vary with each iteration of a read from a guest OS.
The previous implementation had very poor resolution. It
also didn't check the mask bit to see if an apic timer
interrupt should occur on countdown to 0. The apic timer
now calls its own bochs timer, rather than tag on the
one in iodev/devices.cc.
I needed to use one new function which is an inline in
pc_sytem.h. That would have to be added to the old pc_system.h if
we have to back-out to it.
Linux/x86-64 now boots until it hits two undefined opcodes:
FXRSTOR (0f ae). This restores FPU, MMX, XMM and MXCSR registers
from a 512-byte region of memory. We don't implement this yet.
MOVNTDQ (66 0f e7). This is a move involving an XMM register.
The 0x66 prefix is used so it's a double quadword, rather than
MOVNTQ (0f e7) which operates on a single quadword.
The Linux kernel panic is on the MOVNTQD opcodes. Perhaps that's
because that opcode is used in exception handling of the 1st?
Looks like we need to implement some new instructions.
instead of winmm being a part of GUI_LINK_OPTS_WIN32 only, it is
placed in @DEVICE_LINE_OPTS@ so that it will be used for sdl, rfb, wx,
etc.
- solve compile problems when building bximage, niclist, and any other
console based program. The compile flags returned by wx-config and
sdl-config did strange things to these console programs, for example
redefining main to SDL_main. Because I wanted to use the
configure-generated CFLAGS to compile the programs, but I wanted to
avoid including GUI specific compile options, I split up the configure's
@CFLAGS@ variable into @CFLAGS@ and @GUI_CFLAGS@, and split
@CXXFLAGS@ into @CXXFLAGS@ and @GUI_CXXFLAGS@. All programs in the
Bochs binary will use both, but the console programs will just use
@CFLAGS@ or @CXXFLAGS@.
- gui/Makefile.in, I no longer use the gui specific CFLAGS variables,
SDL_CFLAGS and WX_CXXFLAGS. These values are included in CFLAGS and
CXXFLAGS now.
- modified: configure.in, configure, all Makefile.in's
restart another one in wxWindows. Fixed that. Also, on restart, the
apic id's left over from the first run were causing panics. Fixed that.
- modified: main.cc cpu/apic.cc cpu/cpu.h cpu/init.cc
up pc_system.h. Moved all variables under the private: section,
as well as a few member functions. The string instructions
were accessing a field directly (only reads), so I indirected
that via an inline member function for better abstraction.
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.
now simply return a cached value which is set upon mode changes.
The biggest problem was protected_mode() which did something like:
return CR0.PM && ! EFLAGS.VM
This adds up when it was being executed many times in branch functions
etc. Now, cached values are set and sampled instead.
Used patch.disasm to do
1) clean up the disasm output to make the dispaly of extra stuff optional.
2) included the part of the patch which displays displacements as
proper addresses.
and Jas Sandys-Lumsdaine to split out common instructions into
variants which deal with the mod=11b case (Reg-Reg) and the
other cases (which do memory ops). Actually, I only split
MOV_GwEw and MOV_GdEd for now. According to some instrumentation
of a Win95 boot, they were the most frequently used opcode by far.
Essentially, when I coded a few of the instructions to use
asm()s for acceleration of the eflags, I got lazy and only
used the asm() to compute eflags and let the normal C operation
do the actual operation. Jas's patch, moved the asm()s such
that they now do the work of the operation as well.
The patches look great. The code reads a lot better as well.
Further work can be done to give the compiler more options with
register scheduling.
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
Some things changed in the ctrl_xfer*.cc, fetchdecode*.cc,
and cpu.cc since the original patches, so I did some patch
integration by hand. Check the placement of the
macros BX_INSTR_FETCH_DECODE_COMPLETED() and BX_INSTR_OPCODE()
in cpu.cc to make sure I go them right. Also, I changed the
parameters to BX_INSTR_OPCODE() to update them to the new code.
I put some comments before each of these to help determine if
the placement is right.
These macros are only compiled in if you are gathering instrumentation
data from bochs, so they shouldn't effect others.
Created 64-bit versions of some branch instructions and
changed fetchdecode64.cc to use them instead. This keeps the
#ifdef pollution down for 32-bit code and made fixing them
easier. They needed to clear the upper bits of RIP for
16-bit operand sizes. They also should not have had a protection
limit check in them, especially since that field is still
32-bit in cpu.h, so there's no way to set nominal 64-bit values.
The 32-bit versions were also not honoring the upper 32-bits
of RIP.
LOOPNE64_Jb
LOOPE64_Jb
LOOP64_Jb
JCXZ64_Jb
Changed all occurances of JCC_Jw/JCC_Jd in fetchdecode64.cc to
use JCC_Jq, which was coded already. Both JMP_Jq and JCC_Jq are
now fixed w.r.t. 16-bit opsizes and upper RIP bit clearing.
63..16 when a 16-bit operand size JMP is executed. Previous
fix cleared only 63..32. I since realized, this is the case
which does parallel the 32-bit semantics.
fetching 64-bit address opcode info, which was incorrect.
Fixed. Got rid of BxImmediate_Oq. fetchdecode64.cc now
uses BxImmediateO, like the fetch routine does. Addresses which
are embedded in the opcode, have a size which depends on
the current addressing size. For long-mode, this is
either 64 (default) or 32 (AddrSize over-ride). BxImmediate_O
now conditionally fetches based on AddrSize.
64-bit bug#2: In JMP_Jq(), when the current operand size is
16-bits, the upper dword of RIP was not being cleared. The
semantics with this case are weird - one would think the
top 48 bits would be cleared, but apparently only the top
32 bits are. Anyways, I fixed this.
Replaced some of the messy immediate fetching (byte-by-byte) in
fetchdecode64.cc with ReadHost{Q,D}WordFromLittleEndian() calls
for cleanliness. Should do this for all the cases, plus
the 32-bit stuff.
Since the SYSCALL replaces the LOADALL instruction, it is incompatible with
earlier CPU types.
At moment, the SYSCALL is only enabled by x86-64 emulation, but the code
can be incorporated in IA32 only emulations.
Instructions added:
0F 05 SYSCALL (replaces LOADALL)
0F 07 SYSRET (new)
TODO: restructure #if ... so that it can be used by non x86-64 emulations.
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().
loadSRegLMNominal() which should be used to load a segment register
in long-mode with nominal values which are compatible with existing
checks and expectations for descriptor cache values.
Fixed 64-bit iret to not do a descriptor fetch if SS selector is null.
Also load SS with loadSRegLMNorminal() in the same case.
was not correct (used == 0, rather than s&0xffc == 0). Also,
with a null SS selector, it was fetching the descriptor anyways.
Put more code inside the if (selector != NULL) clause.
For a temporary measure I added the local INIT_64_DESCRIPTOR
from segment_ctrl_pro.cc, and used it in the case that the
SS selector is null. We need to make a real function which
sets a descriptor in long-mode to nominal values. I'm going
to do that next... I can't stand seeing the current hacks. :^)
Fixed/updated/cleaned guest2host TLB speedups for Long mode.
I now can boot the Linux x86-64 kernel to the VFS mount message,
using all the accelerations.
these from interfering from a normal compile here's what I did.
In config.h.in (which will generate config.h after a configure),
I added a #define called KPL64Hacks:
#define KPL64Hacks
*After* running configure, you must set this by hand. It will
default to off, so you won't get my hacks in a normal compile.
This will go away soon. There is also a macro just after that
called BailBigRSP(). You don't need to enabled that, but you
can. In many of the instructions which seemed like they could
be hit by the fetchdecode64() process, but which also touched
EIP/ESP, I inserted a macro. Usually this macro expands to nothing.
If you like, you can enabled it, and it will panic if it finds
the upper bits of RIP/RSP set. This helped me find bugs.
Also, I cleaned up the emulation in ctrl_xfer{8,16,32}.cc.
There were some really old legacy code snippets which directly
accessed operands on the stack with access_linear. Lots of
ugly code instead of just pop_32() etc. Cleaning those up,
minimized the number of instructions which directly manipulate
the stack pointer, which should help in refining 64-bit support.
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.
- return model=2 so that Linux recognizes the processor as having an APIC.
We don't really know what Hammer returns.
- in SetCR4, allow bits 9 and 10 to be written
the icache pageStamp check too early, before it was known
that the TLB entry would produce a physical address in
range of the normal part of physical memory. PCI accesses
were causing seg faults because of this. I haven't tested
this for PCI.
which says to paste getB_ with flag and then paste with (. It should
be "getB_##flag(void)". Some preprocessors are complaining about pasting
the symbol with the paren.
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.
- don't allow MMX on cpu level < 5.
- require FPU support on cpu level >= 55
- don't allow MMX support without FPU support (moved this check from
cpu/i387.h to config.h)
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.
also extended by the REX.B field on Hammer) is passed to instructions.
I rearranged the bxInstruction_c to free up a field to be used
to pass this info when mod-rm bytes are not used. This got rid
of the ugly ((i->b1 & 7) + i->rex_b) code.
Probably shaved just a very little run time off Hammer emulation,
and even less on x86-32. The resultant is a little cleaner anyways.
in cpu.cc out of the main loop, and into the asynchronous
events handling. I went through all the code paths, and
there doesn't seem to be any reason for that code to be
in the hot loop.
Added another accessor for getting instruction data, called
modC0(). A lot of instructions test whether the mod field
of mod-nnn-rm is 0xc0 or not, ie., it's a register operation
and not memory. So I flag this in fetchdecode{,64}.cc.
This added on the order of 1% performance improvement for
a Win95 boot.
Macroized a few leftover calls to Write_RMV_virtual_xyz()
that didn't get modified in the x86-64 merge. Really, they
just call the real function for now, but I want to have them
available to do direct writes with the guest2host TLB pointers.
but if you hand edit cpu/cpu.h, and change BxICacheEntries,
you can try different sizes. I'll make this more flexible
with configure. For now, use "--enable-icache" with no parameters.
- Modified fetchdecode.cc/fetchdecode64.cc just enough so that
instructions which encode a direct address now use a memory
resolution function which just sticks the immediate address
into rm_addr. With cached instructions we need this.
to bitfields. bxInstruction_c is now 24 bytes, including 4 for
the memory addr resolution function pointer, and 4 for the
execution function pointer (16 + 4 + 4).
Coded more accessors, to abstract access from most code.
with accessors. Had to touch a number of files to update the
access using the new accessors.
Moved rm_addr to the CPU structure, to slim down bxInstruction_c
and to prevent future instruction caching from getting sprayed
with writes to individual rm_addr fields. There only needs to
be one. Though need to deal with instructions which have
static non-modrm addresses, but which are using rm_addr since
that will change.
bxInstruction_c is down to about 40 bytes now. Trying to
get down to 24 bytes.
read all param values from CPU #0. The only solution I can come up with
is to change the siminterface handler function interface to pass a void*
to the callback function. I'll take care of it eventually.
use accessors. This lets me work on compressing the
size of fetch-decode structure (now called bxInstruction_c).
I've reduced it down to about 76 bytes. We should be able
to do much better soon. I needed the abstraction of the
accessors, so I have a lot of freedom to re-arrange things
without making massive future changes.
Lost a few percent of performance in these mods, but my
main focus was to get the abstraction.
no longer used. Also rearranged that struct a little
to be more compressed. Over time, I'm going to reduce
it further, for use with future accelerations.
enhancement to bochs. You can now configure with
--enable-guest2host-tlb.
Force the support of big pages (PSE) when x86-64 is configured.
Reverted back to only one kind of TLB entry style, since everything
is ported.
Fixed one bug in io.cc with as_64 and the index registers.
There are others, as noticed by Peter.
class declaration, for example:
static const unsigned os_64=0, as_64=0;
After reading some suggestions on usenet, I changed these into
enums instead, like this:
enum { os_64=0, as_64=0 };
be used at all, and Peter didn't want it. "extdb.o" is compiled
into libcpu.a, if configured for it.
Removed a few #warnings for x86-64 compile, based on Peter's
line-item comments regarding the warnings I inserted during
the port/merge.