Add Enzyme AD support

enzyme_support.sh

@@ -0,0 +1,118 @@
+# This file pulls down specific verisons of enzyme and LLVM and compiles them. Use the clang binary
+# that is compiled locally with the enzyme LLVM/Clang plugin, this will guarantee that the plugin
+# works.
+#
+# This version of the enzyme plugin has been tested with the clang-16 available through the apt
+# package manager (does not work correctly with the enzyme plugin) and a locally compiled version
+# (does work).
+#
+# Notes:
+# - For the cmake build specify the location of the local clang binaries like so:
+# `CC=.enzyme_build/llvm-project/build/bin/clang CXX=.enzyme_build/llvm-project/build/bin/clang++ cmake ...`
+#
+# - Compilation with enzyme autodiff functions requires the `-fplugin=.enzyme_build/Enzyme/enzyme/build/Enzyme/ClangEnzyme-16.so` flag
+#   - Using `LLVMEnzyme-16.so` instead of `ClangEnzyme-16.so` is an easy mistake to make and will lead to linker errors
+
+
+# directory where enzyme and llvm will be cloned and compiled
+EAD_LLVM_DIR="$PWD/.enzyme_build"
+
+# version of the llvm-project to pull down; this will almost certainly change as enzyme evolves
+LLVM_BRANCH="llvmorg-16.0.0"
+# directory the llvm-project will be cloned to
+LLVM_DIR="$EAD_LLVM_DIR/llvm-project"
+# llvm lib binaries
+LLVM_LIB="$LLVM_DIR/build/lib/cmake/llvm"
+
+# version of enzyme to pull down
+ENZYME_BRANCH="v0.0.133"
+# directory enzyme will be cloned to
+ENZYME_DIR="$EAD_LLVM_DIR/Enzyme"
+
+build_llvm() {
+    # move to the llvm drectory and create a build directory
+    cd $LLVM_DIR
+    mkdir -p "build" && cd "build"
+
+    # configure the build
+    cmake -G Ninja "../llvm" \
+        -DLLVM_TARGETS_TO_BUILD="host" \
+        -DLLVM_ENABLE_PROJECTS="clang;lld;openmp" \
+        -DLLVM_ENABLE_PLUGINS=ON \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DLLVM_ENABLE_ASSERTIONS=ON
+
+    # exit if configuration failed
+    if [ $? -ne 0 ]; then
+        exit 1
+    fi
+
+    # start build
+    ninja
+
+    # exit if the build failed (enzyme depends on this build)
+    if [ $? -ne 0 ]; then
+        exit 1
+    fi
+}
+
+build_enzyme() {
+    # move to the enzyme repo and create the build dir
+    cd $ENZYME_DIR/enzyme
+    mkdir -p "build" && cd "build"
+
+    # configure the build
+    cmake -G Ninja .. \
+        -DLLVM_DIR=$LLVM_LIB
+
+    # exit if configuration failed
+    if [ $? -ne 0 ]; then
+        exit 1
+    fi
+
+    # start build
+    ninja
+
+    # exit if the build failed
+    if [ $? -ne 0 ]; then
+        exit 1
+    fi
+
+    # run enzyme tests (to make sure it's compiled correctly)
+    ninja check-enzyme
+
+    # run integration tests (to make sure it works with clang correctly)
+    ninja check-enzyme-integration
+}
+
+# create a directory to build enzyme and LLVM
+mkdir -p $EAD_LLVM_DIR && cd $EAD_LLVM_DIR
+
+# pull down llvm and enzyme
+stat $LLVM_DIR
+if [ $? -ne 0]; then
+    git clone --branch $LLVM_BRANCH "https://github.com/llvm/llvm-project.git" $LLVM_DIR
+
+    if [ $? -ne 0 ]; then
+        echo "Could not clone LLVM; exitting..."
+        exit 1
+    fi
+fi
+
+stat $ENZYME_DIR
+if [ $? -ne 0 ]; then
+    git clone --branch $ENZYME_BRANCH "https://github.com/EnzymeAD/Enzyme.git" $ENZYME_DIR
+
+    if [ $? -ne 0 ]; then
+        echo "Could not clone Enzyme; exitting..."
+        exit 1
+    fi
+fi
+
+# start llvm build
+build_llvm
+
+# start enzyme build
+build_enzyme
+
+exit 0