bpo-29469: Move constant folding to AST optimizer (GH-2858)

Author: methane

Doc/whatsnew/3.7.rst

@@ -581,6 +581,9 @@ Optimizations
   and :meth:`selectors.DevpollSelector.modify` may be around 10% faster under
   heavy loads. (Contributed by Giampaolo Rodola' in :issue:`30014`)
 
+* Constant folding is moved from peephole optimizer to new AST optimizer.
+  (Contributed by Eugene Toder and INADA Naoki in :issue:`29469`)
+
 Build and C API Changes
 =======================
 

Include/compile.h

@@ -75,6 +75,8 @@ PyAPI_FUNC(PyObject*) _Py_Mangle(PyObject *p, PyObject *name);
 #define PY_INVALID_STACK_EFFECT INT_MAX
 PyAPI_FUNC(int) PyCompile_OpcodeStackEffect(int opcode, int oparg);
 
+PyAPI_FUNC(int) _PyAST_Optimize(struct _mod *, PyArena *arena);
+
 #ifdef __cplusplus
 }
 #endif

Makefile.pre.in

@@ -319,6 +319,7 @@ PYTHON_OBJS=	\
 		Python/Python-ast.o \
 		Python/asdl.o \
 		Python/ast.o \
+		Python/ast_opt.o \
 		Python/bltinmodule.o \
 		Python/ceval.o \
 		Python/compile.o \

Misc/NEWS.d/next/Core and Builtins/2017-07-26-00-20-15.bpo-29469.potmyI.rst

@@ -0,0 +1,2 @@
+Move constant folding from bytecode layer to AST layer.
+Original patch by Eugene Toder.

PCbuild/pythoncore.vcxproj

@@ -356,6 +356,7 @@
     <ClCompile Include="..\Python\_warnings.c" />
     <ClCompile Include="..\Python\asdl.c" />
     <ClCompile Include="..\Python\ast.c" />
+    <ClCompile Include="..\Python\ast_opt.c" />
     <ClCompile Include="..\Python\bltinmodule.c" />
     <ClCompile Include="..\Python\bootstrap_hash.c" />
     <ClCompile Include="..\Python\ceval.c" />

PCbuild/pythoncore.vcxproj.filters

@@ -824,6 +824,9 @@
     <ClCompile Include="..\Python\ast.c">
       <Filter>Python</Filter>
     </ClCompile>
+    <ClCompile Include="..\Python\ast_opt.c">
+      <Filter>Python</Filter>
+    </ClCompile>
     <ClCompile Include="..\Python\bltinmodule.c">
       <Filter>Python</Filter>
     </ClCompile>