GH-113464: Add a JIT backend for tier 2 (GH-113465)

Add an option (--enable-experimental-jit for configure-based builds
or --experimental-jit for PCbuild-based ones) to build an
*experimental* just-in-time compiler, based on copy-and-patch (https://fredrikbk.com/publications/copy-and-patch.pdf).

See Tools/jit/README.md for more information on how to install the required build-time tooling.

Author: brandtbucher

.github/workflows/jit.yml

@@ -0,0 +1,112 @@
+name: JIT
+on:
+  pull_request:
+    paths: '**jit**'
+  push:
+    paths: '**jit**'
+  workflow_dispatch:
+jobs:
+  jit:
+    name: ${{ matrix.target }} (${{ matrix.debug && 'Debug' || 'Release' }})
+    runs-on: ${{ matrix.runner }}
+    strategy:
+      fail-fast: false
+      matrix:
+        target:
+          - i686-pc-windows-msvc/msvc
+          - x86_64-pc-windows-msvc/msvc
+          - x86_64-apple-darwin/clang
+          - x86_64-unknown-linux-gnu/gcc
+          - x86_64-unknown-linux-gnu/clang
+          - aarch64-unknown-linux-gnu/gcc
+          - aarch64-unknown-linux-gnu/clang
+        debug:
+          - true
+          - false
+        llvm:
+          - 16
+        include:
+          - target: i686-pc-windows-msvc/msvc
+            architecture: Win32
+            runner: windows-latest
+            compiler: msvc
+          - target: x86_64-pc-windows-msvc/msvc
+            architecture: x64
+            runner: windows-latest
+            compiler: msvc
+          - target: x86_64-apple-darwin/clang
+            architecture: x86_64
+            runner: macos-latest
+            compiler: clang
+            exclude: test_embed
+          - target: x86_64-unknown-linux-gnu/gcc
+            architecture: x86_64
+            runner: ubuntu-latest
+            compiler: gcc
+          - target: x86_64-unknown-linux-gnu/clang
+            architecture: x86_64
+            runner: ubuntu-latest
+            compiler: clang
+          - target: aarch64-unknown-linux-gnu/gcc
+            architecture: aarch64
+            runner: ubuntu-latest
+            compiler: gcc
+            # These fail because of emulation, not because of the JIT:
+            exclude: test_unix_events test_init test_process_pool test_shutdown test_multiprocessing_fork test_cmd_line test_faulthandler test_os test_perf_profiler test_posix test_signal test_socket test_subprocess test_threading test_venv
+          - target: aarch64-unknown-linux-gnu/clang
+            architecture: aarch64
+            runner: ubuntu-latest
+            compiler: clang
+            # These fail because of emulation, not because of the JIT:
+            exclude: test_unix_events test_init test_process_pool test_shutdown test_multiprocessing_fork test_cmd_line test_faulthandler test_os test_perf_profiler test_posix test_signal test_socket test_subprocess test_threading test_venv
+    env:
+      CC: ${{ matrix.compiler }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Windows
+        if: runner.os == 'Windows'
+        run: |
+          choco install llvm --allow-downgrade --no-progress --version ${{ matrix.llvm }}
+          ./PCbuild/build.bat --experimental-jit ${{ matrix.debug && '-d' || '--pgo' }} -p ${{ matrix.architecture }}
+          ./PCbuild/rt.bat ${{ matrix.debug && '-d' }} -p ${{ matrix.architecture }} -q --exclude ${{ matrix.exclude }} --multiprocess 0 --timeout 3600 --verbose2 --verbose3
+
+      - name: macOS
+        if: runner.os == 'macOS'
+        run: |
+          brew install llvm@${{ matrix.llvm }}
+          export SDKROOT="$(xcrun --show-sdk-path)"
+          ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '--enable-optimizations --with-lto' }}
+          make all --jobs 3
+          ./python.exe -m test --exclude ${{ matrix.exclude }} --multiprocess 0 --timeout 3600 --verbose2 --verbose3
+
+      - name: Native Linux
+        if: runner.os == 'Linux' && matrix.architecture == 'x86_64'
+        run: |
+          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
+          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
+          ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '--enable-optimizations --with-lto' }}
+          make all --jobs 4
+          ./python -m test --exclude ${{ matrix.exclude }} --multiprocess 0 --timeout 3600 --verbose2 --verbose3
+      - name: Emulated Linux
+        if: runner.os == 'Linux' && matrix.architecture != 'x86_64'
+        run: |
+          sudo bash -c "$(wget -O - https://apt.llvm.org/llvm.sh)" ./llvm.sh ${{ matrix.llvm }}
+          export PATH="$(llvm-config-${{ matrix.llvm }} --bindir):$PATH"
+          ./configure --prefix="$(pwd)/../build"
+          make install --jobs 4
+          make clean --jobs 4
+          export HOST=${{ matrix.architecture }}-linux-gnu
+          sudo apt install --yes "gcc-$HOST" qemu-user
+          ${{ !matrix.debug && matrix.compiler == 'clang' && './configure --enable-optimizations' || '' }}
+          ${{ !matrix.debug && matrix.compiler == 'clang' && 'make profile-run-stamp --jobs 4' || '' }}
+          export CC="${{ matrix.compiler == 'clang' && 'clang --target=$HOST' || '$HOST-gcc' }}"
+          export CPP="$CC --preprocess"
+          export HOSTRUNNER=qemu-${{ matrix.architecture }}
+          export QEMU_LD_PREFIX="/usr/$HOST"
+          ./configure --enable-experimental-jit ${{ matrix.debug && '--with-pydebug' || '--enable-optimizations --with-lto' }} --build=x86_64-linux-gnu --host="$HOST" --with-build-python=../build/bin/python3 --with-pkg-config=no ac_cv_buggy_getaddrinfo=no ac_cv_file__dev_ptc=no ac_cv_file__dev_ptmx=yes
+          make all --jobs 4
+          ./python -m test --exclude ${{ matrix.exclude }} --multiprocess 0 --timeout 3600 --verbose2 --verbose3

.github/workflows/mypy.yml

@@ -12,6 +12,7 @@ on:
       - "Tools/build/generate_sbom.py"
       - "Tools/cases_generator/**"
       - "Tools/clinic/**"
+      - "Tools/jit/**"
       - "Tools/peg_generator/**"
       - "Tools/requirements-dev.txt"
       - "Tools/wasm/**"
@@ -38,6 +39,7 @@ jobs:
           "Tools/build/",
           "Tools/cases_generator",
           "Tools/clinic",
+          "Tools/jit",
           "Tools/peg_generator",
           "Tools/wasm",
         ]

.gitignore

@@ -126,6 +126,7 @@ Tools/unicode/data/
 # hendrikmuhs/ccache-action@v1
 /.ccache
 /cross-build/
+/jit_stencils.h
 /platform
 /profile-clean-stamp
 /profile-run-stamp

Include/cpython/optimizer.h

@@ -39,6 +39,8 @@ typedef struct {
 typedef struct _PyExecutorObject {
     PyObject_VAR_HEAD
     _PyVMData vm_data; /* Used by the VM, but opaque to the optimizer */
+    void *jit_code;
+    size_t jit_size;
     _PyUOpInstruction trace[1];
 } _PyExecutorObject;
 

Include/internal/pycore_jit.h

@@ -0,0 +1,25 @@
+#ifndef Py_INTERNAL_JIT_H
+#define Py_INTERNAL_JIT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef Py_BUILD_CORE
+#  error "this header requires Py_BUILD_CORE define"
+#endif
+
+#ifdef _Py_JIT
+
+typedef _Py_CODEUNIT *(*jit_func)(_PyInterpreterFrame *frame, PyObject **stack_pointer, PyThreadState *tstate);
+
+int _PyJIT_Compile(_PyExecutorObject *executor, _PyUOpInstruction *trace, size_t length);
+void _PyJIT_Free(_PyExecutorObject *executor);
+
+#endif  // _Py_JIT
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // !Py_INTERNAL_JIT_H

Include/internal/pycore_object.h

@@ -178,7 +178,7 @@ _Py_DECREF_SPECIALIZED(PyObject *op, const destructor destruct)
     }
     _Py_DECREF_STAT_INC();
 #ifdef Py_REF_DEBUG
-    _Py_DEC_REFTOTAL(_PyInterpreterState_GET());
+    _Py_DEC_REFTOTAL(PyInterpreterState_Get());
 #endif
     if (--op->ob_refcnt != 0) {
         assert(op->ob_refcnt > 0);
@@ -199,7 +199,7 @@ _Py_DECREF_NO_DEALLOC(PyObject *op)
     }
     _Py_DECREF_STAT_INC();
 #ifdef Py_REF_DEBUG
-    _Py_DEC_REFTOTAL(_PyInterpreterState_GET());
+    _Py_DEC_REFTOTAL(PyInterpreterState_Get());
 #endif
     op->ob_refcnt--;
 #ifdef Py_DEBUG

Makefile.pre.in

@@ -433,6 +433,7 @@ PYTHON_OBJS=	\
 		Python/initconfig.o \
 		Python/instrumentation.o \
 		Python/intrinsics.o \
+		Python/jit.o \
 		Python/legacy_tracing.o \
 		Python/lock.o \
 		Python/marshal.o \
@@ -1365,7 +1366,7 @@ regen-unicodedata:
 regen-all: regen-cases regen-typeslots \
 	regen-token regen-ast regen-keyword regen-sre regen-frozen \
 	regen-pegen-metaparser regen-pegen regen-test-frozenmain \
-	regen-test-levenshtein regen-global-objects regen-sbom
+	regen-test-levenshtein regen-global-objects regen-sbom regen-jit
 	@echo
 	@echo "Note: make regen-stdlib-module-names, make regen-limited-abi, "
 	@echo "make regen-configure and make regen-unicodedata should be run manually"
@@ -1846,6 +1847,7 @@ PYTHON_HEADERS= \
 		$(srcdir)/Include/internal/pycore_initconfig.h \
 		$(srcdir)/Include/internal/pycore_interp.h \
 		$(srcdir)/Include/internal/pycore_intrinsics.h \
+		$(srcdir)/Include/internal/pycore_jit.h \
 		$(srcdir)/Include/internal/pycore_list.h \
 		$(srcdir)/Include/internal/pycore_llist.h \
 		$(srcdir)/Include/internal/pycore_lock.h \
@@ -2641,6 +2643,12 @@ config.status:	$(srcdir)/configure
 Python/asm_trampoline.o: $(srcdir)/Python/asm_trampoline.S
 	$(CC) -c $(PY_CORE_CFLAGS) -o $@ $<
 
+Python/jit.o: regen-jit
+
+.PHONY: regen-jit
+regen-jit:
+	@REGEN_JIT_COMMAND@
+
 # Some make's put the object file in the current directory
 .c.o:
 	$(CC) -c $(PY_CORE_CFLAGS) -o $@ $<
@@ -2733,6 +2741,7 @@ clean-retain-profile: pycremoval
 	-rm -f Python/deepfreeze/*.[co]
 	-rm -f Python/frozen_modules/*.h
 	-rm -f Python/frozen_modules/MANIFEST
+	-rm -f jit_stencils.h
 	-find build -type f -a ! -name '*.gc??' -exec rm -f {} ';'
 	-rm -f Include/pydtrace_probes.h
 	-rm -f profile-gen-stamp

Misc/NEWS.d/next/Core and Builtins/2023-12-24-03-25-28.gh-issue-113464.dvjQmA.rst

@@ -0,0 +1,4 @@
+Add an option (``--enable-experimental-jit`` for ``configure``-based builds
+or ``--experimental-jit`` for ``PCbuild``-based ones) to build an
+*experimental* just-in-time compiler, based on `copy-and-patch
+<https://fredrikbk.com/publications/copy-and-patch.pdf>`_

PCbuild/_freeze_module.vcxproj

@@ -224,6 +224,7 @@
     <ClCompile Include="..\Python\initconfig.c" />
     <ClCompile Include="..\Python\intrinsics.c" />
     <ClCompile Include="..\Python\instrumentation.c" />
+    <ClCompile Include="..\Python\jit.c" />
     <ClCompile Include="..\Python\legacy_tracing.c" />
     <ClCompile Include="..\Python\lock.c" />
     <ClCompile Include="..\Python\marshal.c" />

PCbuild/_freeze_module.vcxproj.filters

@@ -250,6 +250,9 @@
     <ClCompile Include="..\Objects\iterobject.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\Python\jit.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="..\Objects\listobject.c">
       <Filter>Source Files</Filter>
     </ClCompile>