[pypy-svn] r74600 - in pypy/branch/blackhole-improvement/pypy/jit/codewriter: . test

[arigo at codespeak.net]

Author: arigo
Date: Thu May 20 16:25:26 2010
New Revision: 74600

Modified:
   pypy/branch/blackhole-improvement/pypy/jit/codewriter/jtransform.py
   pypy/branch/blackhole-improvement/pypy/jit/codewriter/test/test_jtransform.py
Log:
Optimize a case that occurs in practice (see comment).


Modified: pypy/branch/blackhole-improvement/pypy/jit/codewriter/jtransform.py
==============================================================================
--- pypy/branch/blackhole-improvement/pypy/jit/codewriter/jtransform.py	(original)
+++ pypy/branch/blackhole-improvement/pypy/jit/codewriter/jtransform.py	Thu May 20 16:25:26 2010
@@ -123,9 +123,6 @@
         if (v == c_last_exception or isinstance(v, tuple)
             or v.concretetype != lltype.Bool):
             return False
-        for link in block.exits:
-            if v in link.args:
-                return False   # variable escapes to next block
         for op in block.operations[::-1]:
             if v in op.args:
                 return False   # variable is also used in cur block
@@ -139,6 +136,13 @@
                 # ok! optimize this case
                 block.operations.remove(op)
                 block.exitswitch = (op.opname,) + tuple(op.args)
+                # if the variable escape to the next block along a link,
+                # replace it with a constant, because we know its value
+                for link in block.exits:
+                    while v in link.args:
+                        index = link.args.index(v)
+                        link.args[index] = Constant(link.llexitcase,
+                                                    lltype.Bool)
                 return True
         return False
 

Modified: pypy/branch/blackhole-improvement/pypy/jit/codewriter/test/test_jtransform.py
==============================================================================
--- pypy/branch/blackhole-improvement/pypy/jit/codewriter/test/test_jtransform.py	(original)
+++ pypy/branch/blackhole-improvement/pypy/jit/codewriter/test/test_jtransform.py	Thu May 20 16:25:26 2010
@@ -91,15 +91,22 @@
     assert not Transformer().optimize_goto_if_not(block)
 
 def test_optimize_goto_if_not__exit():
+    # this case occurs in practice, e.g. with RPython code like:
+    #     return bool(p) and p.somefield > 0
     v1 = Variable()
     v2 = Variable()
     v3 = Variable(); v3.concretetype = lltype.Bool
     block = Block([v1, v2])
     block.operations = [SpaceOperation('int_gt', [v1, v2], v3)]
     block.exitswitch = v3
-    block.exits = [FakeLink(False), FakeLink(True)]
+    block.exits = exits = [FakeLink(False), FakeLink(True)]
     block.exits[1].args = [v3]
-    assert not Transformer().optimize_goto_if_not(block)
+    res = Transformer().optimize_goto_if_not(block)
+    assert res == True
+    assert block.operations == []
+    assert block.exitswitch == ('int_gt', v1, v2)
+    assert block.exits == exits
+    assert exits[1].args == [Constant(True, lltype.Bool)]
 
 def test_optimize_goto_if_not__unknownop():
     v3 = Variable(); v3.concretetype = lltype.Bool