[pypy-commit] pypy gc-minimark-pinning: Just move the blocks around to keep the number of flag checks

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: gc-minimark-pinning
Changeset: r54333:549ac1d84b87
Date: 2012-04-13 16:06 +0200
http://bitbucket.org/pypy/pypy/changeset/549ac1d84b87/

Log:	Just move the blocks around to keep the number of flag checks
	minimal in the common case.

diff --git a/pypy/rpython/memory/gc/minimark.py b/pypy/rpython/memory/gc/minimark.py
--- a/pypy/rpython/memory/gc/minimark.py
+++ b/pypy/rpython/memory/gc/minimark.py
@@ -1487,7 +1487,23 @@
             return
         #
         size_gc_header = self.gcheaderbuilder.size_gc_header
-        if self.header(obj).tid & GCFLAG_PINNED:
+        if self.header(obj).tid & (GCFLAG_HAS_SHADOW|GCFLAG_PINNED) == 0:
+            #
+            # Common case: 'obj' was not already forwarded (otherwise
+            # tid == -42, containing all flags), and it doesn't have the
+            # HAS_SHADOW or PINNED flags either.  We must move it out of
+            # the nursery, into a new nonmovable location.
+            totalsize = size_gc_header + self.get_size(obj)
+            newhdr = self._malloc_out_of_nursery(totalsize)
+            #
+        elif self.is_forwarded(obj):
+            #
+            # 'obj' was already forwarded.  Change the original reference
+            # to point to its forwarding address, and we're done.
+            root.address[0] = self.get_forwarding_address(obj)
+            return
+            #
+        elif self.header(obj).tid & GCFLAG_PINNED:
             hdr = self.header(obj)
             if hdr.tid & GCFLAG_VISITED:
                 return
@@ -1497,21 +1513,6 @@
             self.surviving_pinned_objects.insert(
                 llarena.getfakearenaaddress(obj - size_gc_header))
             return
-        elif self.header(obj).tid & GCFLAG_HAS_SHADOW == 0:
-            #
-            # Common case: 'obj' was not already forwarded (otherwise
-            # tid == -42, containing all flags), and it doesn't have the
-            # HAS_SHADOW flag either.  We must move it out of the nursery,
-            # into a new nonmovable location.
-            totalsize = size_gc_header + self.get_size(obj)
-            newhdr = self._malloc_out_of_nursery(totalsize)
-            #
-        elif self.is_forwarded(obj):
-            #
-            # 'obj' was already forwarded.  Change the original reference
-            # to point to its forwarding address, and we're done.
-            root.address[0] = self.get_forwarding_address(obj)
-            return
             #
         else:
             # First visit to an object that has already a shadow.