[Python-checkins] python/dist/src/Lib/test test_peepholer.py, NONE, 1.1 test_dis.py, 1.4, 1.5

[rhettinger at users.sourceforge.net]

Update of /cvsroot/python/python/dist/src/Lib/test
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv23266/Lib/test

Modified Files:
	test_dis.py 
Added Files:
	test_peepholer.py 
Log Message:
SF Patch #1013667:  Cleanup Peepholer Output

* Make a pass to eliminate NOPs.  Produce code that is more readable, 
  more compact, and a tiny bit faster.  Makes the peepholer more flexible
  in the scope of allowable transformations.

* With Guido's okay, bumped up the magic number so that this patch gets
  widely exercised before the alpha goes out.



--- NEW FILE: test_peepholer.py ---
import dis
import sys
from cStringIO import StringIO
import unittest

def disassemble(func):
    f = StringIO()
    tmp = sys.stdout
    sys.stdout = f
    dis.dis(func)
    sys.stdout = tmp
    result = f.getvalue()
    f.close()
    return result

def dis_single(line):
    return disassemble(compile(line, '', 'single'))

class TestTranforms(unittest.TestCase):

    def test_unot(self):
        # UNARY_NOT JUMP_IF_FALSE POP_TOP  -->  JUMP_IF_TRUE POP_TOP'
        def unot(x):
            if not x == 2:
                del x
        asm = disassemble(unot)
        for elem in ('UNARY_NOT', 'JUMP_IF_FALSE'):
            self.assert_(elem not in asm)
        for elem in ('JUMP_IF_TRUE', 'POP_TOP'):
            self.assert_(elem in asm)

    def test_elim_inversion_of_is_or_in(self):
        for line, elem in (
            ('not a is b', '(is not)',),
            ('not a in b', '(not in)',),
            ('not a is not b', '(is)',),
            ('not a not in b', '(in)',),
            ):
            asm = dis_single(line)
            self.assert_(elem in asm)

    def test_none_as_constant(self):
        # LOAD_GLOBAL None  -->  LOAD_CONST None
        def f(x):
                None
                return x
        asm = disassemble(f)
        for elem in ('LOAD_GLOBAL',):
            self.assert_(elem not in asm)
        for elem in ('LOAD_CONST', '(None)'):
            self.assert_(elem in asm)

    def test_while_one(self):
        # Skip over:  LOAD_CONST trueconst  JUMP_IF_FALSE xx  POP_TOP
        def f():
                while 1:
                        pass
                return list
        asm = disassemble(f)
        for elem in ('LOAD_CONST', 'JUMP_IF_FALSE'):
            self.assert_(elem not in asm)
        for elem in ('JUMP_ABSOLUTE',):
            self.assert_(elem in asm)

    def test_pack_unpack(self):
        for line, elem in (
            ('a, = 1,', 'LOAD_CONST',),
            ('a, b = 1, 2', 'ROT_TWO',),
            ('a, b, c = 1, 2, 3', 'ROT_THREE',),
            ):
            asm = dis_single(line)
            self.assert_(elem in asm)
            self.assert_('BUILD_TUPLE' not in asm)
            self.assert_('UNPACK_TUPLE' not in asm)

    def test_elim_extra_return(self):
        # RETURN LOAD_CONST None RETURN  -->  RETURN
        def f(x):
            return x
        asm = disassemble(f)
        self.assert_('LOAD_CONST' not in asm)
        self.assert_('(None)' not in asm)
        self.assertEqual(asm.split().count('RETURN_VALUE'), 1)



def test_main(verbose=None):
    import sys
    from test import test_support
    test_classes = (TestTranforms,)
    test_support.run_unittest(*test_classes)

    # verify reference counting
    if verbose and hasattr(sys, "gettotalrefcount"):
        import gc
        counts = [None] * 5
        for i in xrange(len(counts)):
            test_support.run_unittest(*test_classes)
            gc.collect()
            counts[i] = sys.gettotalrefcount()
        print counts

if __name__ == "__main__":
    test_main(verbose=True)

Index: test_dis.py
===================================================================
RCS file: /cvsroot/python/python/dist/src/Lib/test/test_dis.py,v
retrieving revision 1.4
retrieving revision 1.5
diff -u -d -r1.4 -r1.5
--- test_dis.py	30 Apr 2003 08:42:19 -0000	1.4
+++ test_dis.py	23 Aug 2004 23:37:47 -0000	1.5
@@ -18,8 +18,6 @@
 
  %-4d         5 LOAD_CONST               1 (1)
               8 RETURN_VALUE
-              9 LOAD_CONST               0 (None)
-             12 RETURN_VALUE
 """%(_f.func_code.co_firstlineno + 1,
      _f.func_code.co_firstlineno + 2)