Ripping out the GC

Build

git clone --recurse-submodules https://github.com/prismlab/ocaml-gc-hacking
#Build the unchanged compiler
cd ocaml-gc-hacking/ocaml-4.14-unchanged
./configure --prefix=`pwd`/_install  --disable-naked-pointers
make -j
make install
#Build the modified compiler
cd ../ocaml-4.14-hacked-gc
./configure --disable-naked-pointers
make -C runtime -j ocamlrun ocamlrund
#Run tests
cd ../tests
make

Checkout bdwgc branch

Need to have bdwgc installed globally

git worktree add ../bdwgc-branch origin/bdwgc

Run the same build steps as hacked-gc

Running binarytrees.ml

MIN_EXPANSION_WORDSIZE=2097152 HEIGHT=10 make -B binarytrees.byte

• MIN_EXPANSION_WORDSIZE controls the size of heap chunk allocated by the allocator. The size of heap will be MIN_EXPANSION_WORDSIZE * <word-size>.
• HEIGHT is the parameter used in binarytrees.ml

Repositories

• ocaml-4.14-unchanged -- The unchanged OCaml 4.14 compiler. Used for compiling OCaml programs.
• ocaml-4.14-hacked-gc -- The hacked OCaml 4.14 compiler. This contains the modified ocamlrun used to run the modified GC. There are 3 modified branches:
  • malloc-nogc -- uses malloc and does not GC
  • bdwgc -- uses Boehm GC
  • verified-gc -- uses the verified GC (+ unverified allocator). This is the branch that's pointed to by default in the submodule.
• tests -- contains some test