Old .o files stop working if they use floating point. One must
recompile those files. Old files don't call libfp in the correct way,
and may use symbols that I removed from libem. I don't keep old
symbols in libem/flp.s, because a program that pulls both libfp and
flp.s would get "multiply defined" errors in the linker.
I teach mach/i80/ncg/table to use libfp by copying or adapting the
patterns from mach/i86/ncg/table. I did not test all the patterns,
but I did use `ack -mcpm -fp -O4` to compile examples/mandelbrot.c,
then I ran it in the emulator YAZE-AG. It worked, but it was slow.
I compiled tests/plat/lib/test.c with ack -mcpm, but i80 ncg did emit
wrong code in writehex(uint32_t) for
"0123456789abcdef"[code & 0xf]
The code called '.and' to evaluate `code & 0xf`, then tried to call
'.cii' to narrow the result from 4 to 2 bytes, but it passed garbage
instead of 4 to '.cii'. The rule for '.and' was
pat and defined($1)
kills ALL
uses dereg={const2,$1}
gen Call {label,".and"}
This failed to kill register de={const2,4}, so ncg pushed de,
expecting to push 4, but actually pushing garbage.
Fix such rules using `mvi a,...` or `lxi de,...` so ncg doesn't track
the token in the register. This is like the i86 table. A different
fix would use a dummy instruction `killreg a` or `killreg de` like the
m68020 table.
Also correct 1 to $1 when calling '.exg'.
Errors in 'pat loc cmi teq' and 'pat loc cmi tne' recovered.
Second stack-pattern for 'pat zlt' and 'pat zge' added.
Patterns for 'lil loc adi sil', 'lil inc sil', 'lil dec sil'
and 'sil lil' added.
