While running some silly benchmarks I discovered dc's '^' operator
limits exponents to '9999'. This seems arbitrary, perhaps a leftover
safety measure to keep things from eating all the CPU for days on
end on a slow machine? I upped the limit to 99999 and the test
expression ran fine on a Pi4:
/n/dump/2019/1215.2/sys/src/cmd/dc.c:328,334 - dc.c:328,334
neg++;
chsign(arg1);
}
- if(length(arg1)>=3) {
+ if(length(arg1)>=4) {
error("exp too big\n");
}
savk = sunputc(arg2);
If you're feeling bored and apply the above patch, consider running
this mini-bench and mailing the output directly to me:
echo -n `{cat /dev/cputype}^' ** ' ; echo 652342 52342 '^' 34232342 / p q |
time dc >/dev/null
It will take a while to run (50 minutes on the Pi4).
--lyndon
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