Instead of markGlobals calling markRoots unconditionally (which doesn't
make sense for -gc=none and -gc=leaking), provide markRoots as a
callback function.
This is in preparation for -gc=boehm, where the previous design is even
more awkward and a callback makes far more sense.
I've tested the size impact using `make smoketest XTENSA=0`. There is
none, except for two cases:
* One with `-opt=0` so const-propagation for the callback didn't take
place.
* One other on AVR, I don't know why but as it's only 16 bytes in a
very specific case I'm going to assume it's just a random change in
compiler output that caused a size difference.
This implements the block-based GC as a partially precise GC. This means
that for most heap allocations it is known which words contain a pointer
and which don't. This should in theory make the GC faster (because it
can skip non-pointer object) and have fewer false positives in a GC
cycle. It does however use a bit more RAM to store the layout of each
object.
Right now this GC seems to be slower than the conservative GC, but
should be less likely to run out of memory as a result of false
positives.
Precise globals require a whole program optimization pass that is hard
to support when building packages separately. This patch removes support
for these globals by converting the last use (Linux) to use
linker-defined symbols instead.
For details, see: https://github.com/tinygo-org/tinygo/issues/2870
2022-06-01 21:21:30 +02:00
Переименован с src/runtime/gc_globals_conservative.go (Смотреть далее)
