Re: [B2-devel] Still same crash/problem

[Gwenole B. <gb...@di...>]

> I enclose a gzipped copy of the Makefile after the modification. Could 
> you
> tell me if I did ok please?

Hmm, not really. You have:

cpufast5.s: cpuemu.cpp $(OBJ_DIR)/cpuopti
         $(CXX) $(CPPFLAGS) $(DEFS) -DPART_5 -S $(CXXFLAGS) $< -o 
cputmp5.s
         $(OBJ_DIR)/cat <cputmp5.s >$@ || mv cputmp5.s $@
         rm -f cputmp5.s

instead of

cpufast5.s: cpuemu.cpp $(OBJ_DIR)/cpuopti
         $(CXX) $(CPPFLAGS) $(DEFS) -DPART_5 -S $(CXXFLAGS) $< -o 
cputmp5.s
         /bin/cat <cputmp5.s >$@ || mv cputmp5.s $@
         rm -f cputmp5.s

there is no cat program in the obj/ directory. ;-) then make clean; make

> Oh? I thought that they did heavy optimization and made it proprietary.

Actually, AFAIK, this is still UAE-JIT inside but for QNX. As such, 
source has to be provided. H&P actually *removed* an optimization they 
say is bogus but without providing a hint at what the problem is 
exactly, despite a vague note about ADDI/SUBI.

Their core is based on Bernie's latest snapshot released before he went 
on holidays nearly one year ago. Since, there were little bug fixes 
(register allocator, shift/rotate instructions).

B2/JIT includes all of that and keeps the above-mentioned optimization 
and even other fixes not yet available in Amithlon. e.g. a little fix to 
the JIT/FPU code generation on non-P6+ cores, more complete 68040 MOVE16 
translations. I keep in touch with Bernie for any updates from him or 
myself.

> The Amithlon 68k engine is wildly fast - it's showing like 1Ghz 68040 
> processor.
> Do u think your JIT can achive this performance????

I will say the core is basically the same but I won't claim such a 
thing. Fact is that it's indeed fast. Speedometer 4.x integer tests on a 
Pentium III/800 show performance in between 10x-20x as of a Quadra 
605/LC 475 (68040 @ 25 MHz). Other reports showed B2/JIT faster than 
Executor too.

Your mileage may vary. However, memory usage is quite huge now. :-/ i.e. 
for a 8 MB translation cache size (recommended value), you will need an 
extra 8 MB for internal data structures of the JIT engine. Plus, the 
usual B2 requirements which are:  <RAM size> + <ROM size> + more or less 
1 MB for various tables and other scratch memory areas. Yes, that's 
fatty and this is unlikely to change.

Bye,
Gwenole (really going to sleep that time)