This library is for software floating point. The i80 back end has
never implemented floating point, and might not be ready for libfp.
This commit only builds libfp without using it.
I edit first/build.lua and plat/build.lua to allow `ack -c.s`, then
use FP.script to edit the assembly code. I edit FP.script so it
writes the edited assembly code to stdout, not to the input file.
- Don't reverse bitfields; do use ego (41f3bf7).
- Use MACHOPT_F=-m2 (3dae9e4).
- Remove old trap.s (26de4c1).
At this commit, one can build qemuppc with mcg by editing the root
build.lua to uncomment "qemuppc" in "vars.plats". If one also
uncomments "qemuppc" from "vars.plats_with_tests", then mcg fails to
build the tests. If one uses ncg (by editing plat/qemuppc/descr to
change "mcg" to "ncg"), then the tests pass.
You may need to delete and recompile some .o files! This changes the
alignment of 8-byte values in C structs to match what Apple's gcc
does. See Apple's "32-bit PowerPC Function Calling Conventions" at
https://developer.apple.com
/library/content/documentation/DeveloperTools/Conceptual/LowLevelABI
/100-32-bit_PowerPC_Function_Calling_Conventions/32bitPowerPC.html
In the instruction list, put /* kills xer */ for sraw, srawi, subfic;
and correct the (now unused) "addi." and "lfdu".
Change MACHOPT_F from -m3 to -m2. This changes the code for 15 * i
from
slwi r3,r4,4
subfic r5,r4,0
add r3,r3,r5
to
mulli r3,r4,15
If the sequence "slwi subfic addi" takes 3 cycles and 12 bytes, and
mulli takes 3 cycles and 4 bytes, then mulli is better.
A signal handler might call sigaction(). We must block all signals,
not only our signal, to prevent a race between us and the next signal
handler.
Use /* comments */ because cpp might expand macros in ! comments
though such expansion is probably harmless.
The bridge is now shorter by 2 instructions.
Rename plat/linux/libsys/errno.s to plat/linux386/libsys/trapno.s and
stop building it for linux68k and linuxppc. It defines symbols for
mach/i386/libem.
In syscalls.h, the numbers after 165 are only for i386, so hide them
from 68k, ppc. These numbers are unused, because the system calls now
in libsys use the lower numbers.
Also teach the build system that libsys depends on the internal
headers in plat/linux/libsys/*.h
The new test rck_e.e segfaults on PowerPC unless I make some changes.
The inline code for _rck_ was wrong because it didn't allow the trap
handler to return. _sig_ forgot to push the old trap handler.
Move plat/linuxppc/libsys/trap.s to mach/powerpc/libem/trp.s and
rewrite it with simplified/extended mnemonics. Remove .trap alias for
.trp procedure. Add a missing `mtspr lr, r0` so we can return from
the trap handler. Call write() and _exit() so trp.s works with both
linuxppc and osxppc. Before, Mac OS X was wrongly using the trap.s
for Linux.
In powerpc/libem, simplify .aar4; teach .csa and .csb to raise the
trap if the default target is zero.
C programs don't need these changes. You may relink your C programs
with the changed .csa and .csb, but C code doesn't raise the trap.
Modula-2 code can raise traps, so you may want to relink your Modula-2
programs with the changed libem, but you might keep your old .o files
from Modula-2. You may need to recompile your Pascal programs (delete
old .o files from Pascal) because the Pascal compiler might use _rck_.
ack -mlinuxppc -O4 now runs more phases of ego, including the register
allocation phase, so ncg emits better code.
Set MACHOPT_F=-m3 as I did it for osxppc; see commit 0c2b6f5.
Remove CC_ALIGN=-Vr so bitfields agree with gcc for PowerPC Linux.
Remove unused C_LIB and OLD_C_LIB.
Linux passes the arguments in registers, but our compiler expects
arguments on the stack. Signal handlers got garbage instead of the
signal number. Some handlers, like the one in lang/m2/libm2/sigtrp.c,
need the correct signal number.
I write a "bridge" in PowerPC assembly that moves the arguments to the
stack. I put the bridge in sigaction(), so I provide a signal() that
calls sigaction(). I remove the *.c glob or wildcard from build.lua,
so linuxppc only compiles its own signal.c, not the other signal.c for
linux386 and linux68k.
My bridge uses sigprocmask(), so I also add sigprocmask(). Because
linux386 and linux68k use globs, they also get sigprocmask(). I sync
the header files so all three Linux platforms declare execve(),
sigprocmask(), and unlink(), but not remove(), because we have
remove() in <stdio.h>.
I am using sigaction.s to test some features that we recently added to
our PowerPC assembler. These are the "hi16[...]" and "lo16[...]"
syntax, and also the extended names like "beq", "cmpwi", "li", "subi".
possible values. Add the PowerPC ncg and mcg backend support to let the test
actually run, including modifying a bunch of PowrePC libem functions so that
they can be called from both ncg and mcg.
Without this, qemu-system-ppc spins the host cpu until I close its
window. I assume the default G3 emulation. The emulator yields the
host cpu if I set certain flags in hid0 then msr. The hid0 flag can
be any of DOZE, NAP, SLEEP, so I just set all 3. I encode mfmsr and
mtmsr with .data4, because our assembler doesn't know instructions for
supervisor mode.
Also move some common symbols from .rom to .bss. Our assembler puts
common symbols in any section.
Also clean up the file. Delete a comment about linuxppc that is wrong
here. Delete redundant .extern because .define is the same.
Telling osx386 and osxppc to build and run their own tools, not to
reuse the tools from linux386 and linuxppc. This wastes time to build
identical tools, but it removes some bogus dependencies. OS X tools
had wrongly depended on Linux descr files and aelflod; now they don't.
Discussion in https://github.com/davidgiven/ack/pull/23
Until now, I was always doing chmod +x before running my files on the
Mac. Now files get created +x. There's no change when overwriting
an existing file. I needed to gmake clean my build to remove the
example programs without +x, so cvmach can create them with +x.
If I want to check for overflow, then I should check it before I do
base + incr, not after.
Now that I have no check, I am passing the overflowed base + incr to
brk1(), where it will probably fail the nbreak < segment check.
This manual is in the new mdoc(7) format. All existing ack manuals
use the old man(7) format. This might be a problem if someone can't
display mdoc(7) files.
The build system doesn't install the cvmach(6) manual; that might
happen later. The current build system installs manuals in two
different places, and doesn't install some manuals, so I don't know
what to do.
No change to linuxppc and qemuppc. They continue to run ego without
any descr file.
I copied m68020.descr to powerpc.descr and changed some numbers. My
numbers are guesses; I know little about PowerPC cycle counts, and
almost nothing about ego. This powerpc.descr causes most of the
example programs to shrink in size (without descr -> with descr):
65429 -> 57237 hilo_b.osxppc -8192
36516 -> 32420 hilo_c.osxppc -4096
55782 -> 51686 hilo_mod.osxppc -4096
20096 -> 20096 hilo_p.osxppc 0
8813 -> 8813 mandelbrot_c.osxppc 0
93355 -> 89259 paranoia_c.osxppc -4096
92751 -> 84559 startrek_c.osxppc -8192
(Each file has 2 Mach segments, then a symbol table. Each segment
takes a multiple of 4096 bytes. When the code shrinks, we lose a
multiple of 4096 bytes.)
I used "ack -mosxppc -O6 -c.so" to examine the assembly code for
hilo.mod and mandelbrot.c, both without and with descr. This reveals
optimizations made only with descr, from 2 ego phases: SP (stack
pollution) and RA (register allocation). In hilo.mod, SP deletes some
instructions that remove items from the stack. These items get
removed when the function returns. In both hilo.mod and mandelbrot.c,
RA moves some values into local variables, so ncg can make them into
register variables. This shrinks code size, probably because register
variables get preserved across function calls. More values stay in
registers, and ncg emits shorter code.
I believe that the ego descr file uses (time,space) tuples but the ncg
table uses (space,time) tuples. This is confusing. Perhaps I am
wrong, and some or all tuples are backwards. My time values are the
cycle counts in latency from the MPC7450 Reference Manual (but not
including complications like "store serialization").
In powerpc.descr, I give the cost for saving and restoring registers
as if I was using chains of stw and lwz instructions. Actually ncg
uses single stmw and lmw instructions with at least 2 instructions.
The (time,space) for stmw and lmw would be much less than the
(time,space) for chains of stw and lwz. But this ignores the pipeline
of the MPC7450. The chains of stw and lwz may run faster than stmw
and lmw in the pipeline, because the throughput may be better than the
latency. By using the wrong values for (time,space), I'm trying to
tell ego that stmw and lmw are not better than chains of stw and lwz.
This prevents the warning, "implicit declaration of function raise",
in programs that call raise(). I forgot to declare it because the
function raise() is in libc but the declaration goes in libsys.
David Given made top for PowerPC. Copy the asopt phase (running top)
from linuxppc to osxppc.
Remove CC_ALIGN=-Vr to become compatible with Apple's gcc. Apple uses
left adjustment for bitfields; the first bitfield is on the left side
(the big end), not the right side.
Remove unused variables C_LIB and OLD_C_LIB; the file libc-ansi.a
doesn't exist.
Change MACHOPT_F from -m10 to -m3. This means to use no more than 3
adds and shifts to optimize a multiply by a constant. I pick -m3
because -m4 can use too many instructions. At -m4, the compiler
rewrites
n * 14
as
s = n << 1
(s << 3) + (0 - s)
This means (n * 16 - n * 2), but even at ack -O6, the compiler doesn't
rewrite (a + (0 - b)) as (a - b). The compiler emits 5 instructions:
2 of rlinmw for 2 left shifts, then addi to load 0 in a register, subf
to subtract from that 0, then add. These 5 instructions cost 5 cycles
on the MPC7450, using the cycle counts from mach/powerpc/ncg/table.
At -m3, (n * 14) becomes 2 instructions: addi to load 14 in a register
and mullw to multiply. This also costs 5 cycles (because mullw costs
4 cycles), but uses less space.
This brings in David Given's PowerPC changes, including the addition
of the modern code generator (mcg) for PowerPC.
Resolve minor conflicts in top build.lua and util/led/main.c
Also add fstat() and lstat(). I don't #define the constants for
st_mode or d_type, but I provide enough to get the block size of a
file and to list the names in a directory. Some fields of struct stat
get truncated, see XXX in plat/osx/include/sys/stat.h.
In struct dirent, the inode field might be d_ino or d_fileno. I
picked d_ino because Apple's sys/dirent.h uses d_ino (but Apple's
manual pages use d_fileno).
was nearly useless; lots of fixes to qemuppc and pc86 sbrk(), which was broken;
change the pc86 console to echo output to the serial port (needed for running
tests on qemu).
standard library, because they never worked and come from an achingly old
version of the Pascal specification. Fix the implementations of New() and
Dispose() to use the standard C memory allocator rather than rolling their own
(also in C). Write test!
The system call puts the time in a pair of registers, not in the
timeval structure. Add code to move the time to the structure, so
programs see the correct time, not garbage. This fixes our example
programs that use the time as a random seed.
This preserves the name and value of every symbol. The type and other
info of a symbol might be lost. In gdb, one can now "disas main" or
"disas '.ret'" to disassemble functions by name.
Most symbols are in sections, so I also teach cvmach to emit the Mach
section headers. The entry point in plat/osx*/descr moves down to
make room for the section headers and LC_SYMTAB.
I fix some bugs in calculations of cvmach. They were wrong if ROM had
a greater alignment than TEXT, or if DATA did not start on a page
boundary. I introduce machseg[] to simplify the mess of variables in
main(). I declare most functions as static. Also, cvmach becomes the
first program to #include <object.h>.
corresponding invocation in the ncg table so the same helpers can be used for
both mcg and ncg. Add a new IR opcode, FARJUMP, which jumps to a helper
function but saves volatile registers.
Before this commit, the headers in plat/osx/include got installed
twice into PLATIND/osx386/include and PLATIND/osxppc/include. This
commit installs them once into PLATIND/osx/include and changes both
descr files to find them.
Several rules in lang/ depend on plat/osx386/include+headers or
plat/osxppc/include+headers. They each become a simplerule that
depends on plat/osx/include+headers.
These produce Mach-o executables for Mac OS X on Intel or PowerPC
processors. Our code generator for PowerPC (mach/powerpc) still has
bugs. Some examples seem to run, but startrek crashes. Our code
generator for Intel (mach/i386) is better.
There is a problem with job control. If you run paranoia or startrek,
then suspend the job (^Z) and resume it ('fg' in bash), then read(2)
might fail with EINTR.
The larger files in this commit are
- plat/osx/cvmach/cvmach.c
- plat/osx/libsys/brk.c
- plat/osx386/libsys/sigaction.s
- plat/osxppc/libsys/sigaction.s
I copied the definitions from linux386 and linux68k.
This change also moves _errno and the other common symbols in boot.s
from .text to .bss. Common symbols belong in .bss, but the assembler
seems dumb enough to put them in any section.
Don't define __POWERPC. I don't know any other compiler that defines
__POWERPC and don't want to invent a new macro. Apple's gcc 4.0.1
from Xcode 2.5 defines __ppc__, _ARCH_PPC, __POWERPC__. Debian's gcc
4.9.2-10 defines _ARCH_PPC, __PPC__, __powerpc__, __PPC, __powerpc,
PPC, powerpc.
Move the base vm address from 0x80000000 down to 0x10000000, as this
is where Debian loads /bin/true. This is still higher than the base
addresses for linux386 and linux68k.
Sync led's arguments with linux386.
If it understands TIOCGETD, then it is a tty, else it isn't one. This
seems to help Basic's input statement so I can see the prompt before
I enter my input.
GNU as has "la %r4,8(%r3)" as an alias for "addi %r4,%r3,8", meaning
to load the address of the thing at 8(%r3). Our 'la', now 'li32',
makes an addis/ori pair to load an immediate 32-bit value. For
example, "li32 r4,23456789" loads a big number.
calculated incorrectly because of overflow errors.
Replace it with an extended RELOPPC relocation which understands addis/ori
pairs; add an la pseudoop to the assembler which generates these and the
appropriate relocation. Make good.
--HG--
branch : dtrg-experimental-powerpc-branch
This needed lots of refactoring to ego --- not all platforms have ego descr
files, and ego will just crash if you invoke it without one. I think originally
it was never intended that these platforms would be used at -O2 or above.
Plats now only specify the ego descr file if they have one.
directories --- wrangling descr files was too hard. C programs can be built
for cpm, pc86, linux386, linux68k!
--HG--
branch : dtrg-buildsystem
rename : util/ack/build.mk => util/led/build.mk
rename : util/LLgen/build.mk => util/topgen/build.mk
When the bootloader probes the drive geometry, the BIOS can clobber the
es register. If this happens, the bootloader loads the program to the
wrong address, and jumps off the code. This happens with an emulated
floppy drive in Bochs or QEMU, but not with an emulated hard disk.
