Willy, > > Looks like it decided that non-letter characters had to be encoded. > > We're using FD_ISSET() to look up the characters in the character > > encoding map because this was convenient in the past, but maybe it's > > time to have a native implementation of a bit address lookup and get rid of > > this now. > > I've just created an issue about this one so we don't forget it. > > Willy
FWIW: after a bit of experimentation and a quick dumb behavior comparison program I found that FD_SET is compiled incorrectly by GCC 8.3.0 under Cygwin with optimization level of -O2 and up. I compared native FD_SET/FD_ISSET with hap_fd_set/hap_fd_isset and while the latter always functions correctly, the former broke with -O2 and beyond. Further playing with optimizations enabled by -O2 I was able to narrow the offender down to -ftree-pre, which enables partial redundancy elimination (PRE) on trees. When tree PRE is enabled, GCC generates wrong code for inlined FD_SET in map initialization loop which results in most, and eventually all, bits of the map set when they shouldn't, which explains those superfluous escapes that caused reg-tests failures. When compiled with -fno-tree-pre, most reg-tests now pass. Still, since there is already native implementation of bit address lookup and it seems to work correctly with all optimizations enabled, maybe it's better just to switch to it. Bob
