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 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>.
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
