Issue python#4753: By enabling a configure option named '--with-computed-gotos'

on compilers that support it (notably: gcc, SunPro, icc), the bytecode
evaluation loop is compiled with a new dispatch mechanism which gives
speedups of up to 20%, depending on the system, on various benchmarks.

Author: pitrou

Makefile.pre.in

@@ -247,6 +247,16 @@ ASDLGEN=	$(srcdir)/Parser/asdl_c.py
 
 ##########################################################################
 # Python
+
+OPCODETARGETS_H= \
+		$(srcdir)/Python/opcode_targets.h
+
+OPCODETARGETGEN= \
+		$(srcdir)/Python/makeopcodetargets.py
+
+OPCODETARGETGEN_FILES= \
+		$(OPCODETARGETGEN) $(srcdir)/Lib/opcode.py
+
 PYTHON_OBJS=	\
 		Python/_warnings.o \
 		Python/Python-ast.o \
@@ -567,6 +577,11 @@ Objects/unicodeobject.o: $(srcdir)/Objects/unicodeobject.c \
 				$(BYTESTR_DEPS) \
 				$(srcdir)/Objects/stringlib/formatter.h
 
+$(OPCODETARGETS_H): $(OPCODETARGETGEN_FILES)
+	$(OPCODETARGETGEN) $(OPCODETARGETS_H)
+
+Python/ceval.o: $(OPCODETARGETS_H)
+
 Python/formatter_unicode.o: $(srcdir)/Python/formatter_unicode.c \
 				$(BYTESTR_DEPS)
 

Misc/NEWS

@@ -12,6 +12,11 @@ What's New in Python 3.1 alpha 0
 Core and Builtins
 -----------------
 
+- Issue #4753: By enabling a configure option named '--with-computed-gotos'
+  on compilers that support it (notably: gcc, SunPro, icc), the bytecode
+  evaluation loop is compiled with a new dispatch mechanism which gives
+  speedups of up to 20%, depending on the system, on various benchmarks.
+
 - Issue #4874: Most builtin decoders now reject unicode input.
 
 - Issue #4842: Don't allow trailing 'L' when constructing an integer