[pypy-commit] pypy default: fix for a bug where you do newstr(<const>) copystrcontent strgetitem and the JIT was incorrectly folding teh strgetitem

[alex_gaynor]

Author: Alex Gaynor <alex.gaynor at gmail.com>
Branch: 
Changeset: r47574:1d957571e185
Date: 2011-09-23 22:11 -0400
http://bitbucket.org/pypy/pypy/changeset/1d957571e185/

Log:	fix for a bug where you do newstr(<const>) copystrcontent strgetitem
	and the JIT was incorrectly folding teh strgetitem

diff --git a/pypy/jit/metainterp/optimizeopt/vstring.py b/pypy/jit/metainterp/optimizeopt/vstring.py
--- a/pypy/jit/metainterp/optimizeopt/vstring.py
+++ b/pypy/jit/metainterp/optimizeopt/vstring.py
@@ -368,7 +368,7 @@
 
     def new(self):
         return OptString()
-    
+
     def make_vstring_plain(self, box, source_op, mode):
         vvalue = VStringPlainValue(self.optimizer, box, source_op, mode)
         self.make_equal_to(box, vvalue)
@@ -438,7 +438,11 @@
         #
         if isinstance(value, VStringPlainValue):  # even if no longer virtual
             if vindex.is_constant():
-                return value.getitem(vindex.box.getint())
+                res = value.getitem(vindex.box.getint())
+                # If it is uninitialized we can't return it, it was set by a
+                # COPYSTRCONTENT, not a STRSETITEM
+                if res is not optimizer.CVAL_UNINITIALIZED_ZERO:
+                    return res
         #
         resbox = _strgetitem(self.optimizer, value.force_box(), vindex.force_box(), mode)
         return self.getvalue(resbox)
diff --git a/pypy/jit/metainterp/test/test_string.py b/pypy/jit/metainterp/test/test_string.py
--- a/pypy/jit/metainterp/test/test_string.py
+++ b/pypy/jit/metainterp/test/test_string.py
@@ -1,9 +1,11 @@
 import py
+
+from pypy.jit.codewriter.policy import StopAtXPolicy
+from pypy.jit.metainterp.test.support import LLJitMixin, OOJitMixin
+from pypy.rlib.debug import debug_print
 from pypy.rlib.jit import JitDriver, dont_look_inside, we_are_jitted
-from pypy.rlib.debug import debug_print
-from pypy.jit.codewriter.policy import StopAtXPolicy
+from pypy.rlib.rstring import StringBuilder
 from pypy.rpython.ootypesystem import ootype
-from pypy.jit.metainterp.test.support import LLJitMixin, OOJitMixin
 
 
 class StringTests:
@@ -560,3 +562,17 @@
         self.check_loops({
             "guard_true": 5, "int_is_true": 3, "int_lt": 2, "int_add": 2, "jump": 2,
         }, everywhere=True)
+
+    def test_virtual_copystringcontent(self):
+        jitdriver = JitDriver(reds=['n', 'result'], greens=[])
+        def main(n):
+            result = 0
+            while n >= 0:
+                jitdriver.jit_merge_point(n=n, result=result)
+                b = StringBuilder(6)
+                b.append("Hello!")
+                result += ord(b.build()[0])
+                n -= 1
+            return result
+        res = self.meta_interp(main, [9])
+        assert res == main(9)
\ No newline at end of file