Merge 8600541 into 5593987

docs/blog/index.rst

@@ -6,3 +6,4 @@ Blog
 
    announcing-topaz
    one-year
+   type-specialized-instance-variables

docs/blog/type-specialized-instance-variables.rst

@@ -0,0 +1,54 @@
+Type Specialized Instance Variables
+===================================
+
+**Posted: July 13, 2013**
+
+In Topaz, like most other VMs, all objects are stored in what are called
+"boxes". Essentially that means when you have something like ``x = 5``, ``x``
+is really a pointer to an object which contains ``5``, not the value ``5``
+itself. This is often a source of performance problems for VMs, because it
+generates more garbage for the GC to process and means that to access the value
+``5`` more memory dereferences are needed. Topaz's just-in-time compiler (JIT)
+is often able to remove these allocations and memory dereferences in individual
+loops or functions, however it's not able to remove them in structures that
+stick around in memory, like objects.
+
+Therefore, over the past week I've been working on an optimization for Topaz
+called "type specialized instance variables". Basically what that means is that
+Topaz keeps track of what types instance variables in an object tend to have,
+and then specializes the storage to remove the indirection for ``Fixnum`` and
+``Float`` objects.
+
+Let's look at an example:
+
+.. sourcecode:: ruby
+
+    class Point
+      def initialize(x, y, z)
+        @x = x
+        @y = y
+        @z = z
+      end
+    end
+
+    p = Point.new(1, 2, 3)
+
+Before this optimization, ``p`` looked like this in memory. Each box indicates
+an 8-byte (on 64-bit systems) value, and arrows are pointers:
+
+.. image:: images/type-specialized-instances-before.png
+
+And after the optimization, it looks like this:
+
+.. image:: images/type-specialized-instances-after.png
+
+With this optimization landed, Topaz will use less memory and be faster for
+programs that store ``Fixnum`` and ``Float`` objects in memory. If you're
+interested in this type of optimization you can read about a `similar one in
+PyPy for lists`_ that we're in the process of porting to Topaz.
+
+We're looking forward to doing our first release soon, we hope you'll test
+Topaz out, and give us feedback with the `nightly builds`_ until then
+
+.. _`similar one in PyPy for lists`: http://morepypy.blogspot.com/2011/10/more-compact-lists-with-list-strategies.html
+.. _`nightly builds`: http://topazruby.com/builds/

tests/jit/test_basic.py

@@ -33,45 +33,6 @@ def test_while_loop(self, topaz, tmpdir):
         jump(p0, p1, p3, p4, p5, p6, p7, p10, i40, p20, p22, p28, descr=TargetToken(4310781936))
         """)
 
-    def test_ivar_while_loop(self, topaz, tmpdir):
-        traces = self.run(topaz, tmpdir, """
-        @i = 0
-        while @i < 10000
-          @i += 1
-        end
-        """)
-        self.assert_matches(traces[0].loop, """
-        label(p0, p1, p3, p4, p5, p6, p7, p10, p20, p41, p31, p26, descr=TargetToken(4310781936))
-        debug_merge_point(0, 0, '<main> at LOAD_SELF')
-        debug_merge_point(0, 0, '<main> at LOAD_INSTANCE_VAR')
-        debug_merge_point(0, 0, '<main> at LOAD_CONST')
-        debug_merge_point(0, 0, '<main> at SEND')
-        setfield_gc(p20, 23, descr=<FieldS topaz.executioncontext.ExecutionContext.inst_last_instr 24>)
-        guard_not_invalidated(descr=<Guard0x100ff1088>)
-        p43 = force_token()
-        i44 = getfield_gc_pure(p41, descr=<FieldS topaz.objects.intobject.W_FixnumObject.inst_intvalue 8>)
-        i45 = int_lt(i44, 10000)
-        guard_true(i45, descr=<Guard0x100ff1010>)
-        debug_merge_point(0, 0, '<main> at JUMP_IF_FALSE')
-        debug_merge_point(0, 0, '<main> at LOAD_SELF')
-        debug_merge_point(0, 0, '<main> at DUP_TOP')
-        debug_merge_point(0, 0, '<main> at LOAD_INSTANCE_VAR')
-        debug_merge_point(0, 0, '<main> at LOAD_CONST')
-        debug_merge_point(0, 0, '<main> at SEND')
-        p46 = force_token()
-        i47 = int_add(i44, 1)
-        debug_merge_point(0, 0, '<main> at STORE_INSTANCE_VAR')
-        debug_merge_point(0, 0, '<main> at DISCARD_TOP')
-        debug_merge_point(0, 0, '<main> at JUMP')
-        debug_merge_point(0, 0, '<main> at LOAD_SELF')
-        setfield_gc(p20, 39, descr=<FieldS topaz.executioncontext.ExecutionContext.inst_last_instr 24>)
-        p48 = new_with_vtable(4300302336)
-        setfield_gc(p48, i47, descr=<FieldS topaz.objects.intobject.W_FixnumObject.inst_intvalue 8>)
-        setarrayitem_gc(p26, 0, p48, descr=<ArrayP 8>)
-        i49 = arraylen_gc(p26, descr=<ArrayP 8>)
-        jump(p0, p1, p3, p4, p5, p6, p7, p10, p20, p48, p31, p26, descr=TargetToken(4310781936))
-        """)
-
     def test_constant_string(self, topaz, tmpdir):
         traces = self.run(topaz, tmpdir, """
         i = 0

tests/jit/test_instance_vars.py

@@ -59,3 +59,77 @@ def initialize
         setfield_gc(p24, 58, descr=<FieldS topaz.executioncontext.ExecutionContext.inst_last_instr 24>)
         jump(p0, p1, p3, p4, p5, p7, p10, i49, p19, p22, p24, p30, descr=TargetToken(4310782288))
         """)
+
+    def test_unboxed_int_storage(self, topaz, tmpdir):
+        traces = self.run(topaz, tmpdir, """
+        @i = 0
+        while @i < 10000
+          @i += 1
+        end
+        """)
+        self.assert_matches(traces[0].loop, """
+        label(p0, p1, p3, p4, p5, p6, p7, p10, f39, p20, p31, p26, descr=TargetToken(4310773744))
+        debug_merge_point(0, 0, '<main> at LOAD_SELF')
+        debug_merge_point(0, 0, '<main> at LOAD_INSTANCE_VAR')
+        i42 = convert_float_bytes_to_longlong(f39)
+        debug_merge_point(0, 0, '<main> at LOAD_CONST')
+        debug_merge_point(0, 0, '<main> at SEND')
+        setfield_gc(p20, 23, descr=<FieldS topaz.executioncontext.ExecutionContext.inst_last_instr 24>)
+        guard_not_invalidated(descr=<Guard0x100ff6bd8>)
+        p43 = force_token()
+        i44 = int_lt(i42, 10000)
+        guard_true(i44, descr=<Guard0x100ff6b60>)
+        debug_merge_point(0, 0, '<main> at JUMP_IF_FALSE')
+        debug_merge_point(0, 0, '<main> at LOAD_SELF')
+        debug_merge_point(0, 0, '<main> at DUP_TOP')
+        debug_merge_point(0, 0, '<main> at LOAD_INSTANCE_VAR')
+        debug_merge_point(0, 0, '<main> at LOAD_CONST')
+        debug_merge_point(0, 0, '<main> at SEND')
+        p45 = force_token()
+        i46 = int_add(i42, 1)
+        debug_merge_point(0, 0, '<main> at STORE_INSTANCE_VAR')
+        f47 = convert_longlong_bytes_to_float(i46)
+        debug_merge_point(0, 0, '<main> at DISCARD_TOP')
+        debug_merge_point(0, 0, '<main> at JUMP')
+        debug_merge_point(0, 0, '<main> at LOAD_SELF')
+        setfield_gc(p20, 39, descr=<FieldS topaz.executioncontext.ExecutionContext.inst_last_instr 24>)
+        setarrayitem_gc(p26, 0, f47, descr=<ArrayF 8>)
+        i48 = arraylen_gc(p26, descr=<ArrayF 8>)
+        jump(p0, p1, p3, p4, p5, p6, p7, p10, f47, p20, p31, p26, descr=TargetToken(4310773744))
+        """)
+
+    def test_unboxed_float_storage(self, topaz, tmpdir):
+        traces = self.run(topaz, tmpdir, """
+        @data = 0.0
+        while @data < 10000.0
+          @data += 1.0
+        end
+        """)
+        self.assert_matches(traces[0].loop, """
+        label(p0, p1, p3, p4, p5, p6, p7, p10, p20, f37, p30, p26, descr=TargetToken(4310773744))
+        debug_merge_point(0, 0, '<main> at LOAD_SELF')
+        debug_merge_point(0, 0, '<main> at LOAD_INSTANCE_VAR')
+        debug_merge_point(0, 0, '<main> at LOAD_CONST')
+        debug_merge_point(0, 0, '<main> at SEND')
+        setfield_gc(p20, 23, descr=<FieldS topaz.executioncontext.ExecutionContext.inst_last_instr 24>)
+        guard_not_invalidated(descr=<Guard0x100ff1d30>)
+        p40 = force_token()
+        i41 = float_lt(f37, 10000.000000)
+        guard_true(i41, descr=<Guard0x100ff1cb8>)
+        debug_merge_point(0, 0, '<main> at JUMP_IF_FALSE')
+        debug_merge_point(0, 0, '<main> at LOAD_SELF')
+        debug_merge_point(0, 0, '<main> at DUP_TOP')
+        debug_merge_point(0, 0, '<main> at LOAD_INSTANCE_VAR')
+        debug_merge_point(0, 0, '<main> at LOAD_CONST')
+        debug_merge_point(0, 0, '<main> at SEND')
+        p42 = force_token()
+        f43 = float_add(f37, 1.000000)
+        debug_merge_point(0, 0, '<main> at STORE_INSTANCE_VAR')
+        debug_merge_point(0, 0, '<main> at DISCARD_TOP')
+        debug_merge_point(0, 0, '<main> at JUMP')
+        debug_merge_point(0, 0, '<main> at LOAD_SELF')
+        setfield_gc(p20, 39, descr=<FieldS topaz.executioncontext.ExecutionContext.inst_last_instr 24>)
+        setarrayitem_gc(p26, 0, f43, descr=<ArrayF 8>)
+        i44 = arraylen_gc(p26, descr=<ArrayF 8>)
+        jump(p0, p1, p3, p4, p5, p6, p7, p10, p20, f43, p30, p26, descr=TargetToken(4310773744))
+        """)

tests/test_mapdict.py

@@ -1,39 +1,41 @@
 import pytest
 
-from topaz.mapdict import ClassNode
-
-from .base import BaseTopazTest
+from topaz import mapdict
 
 
 class FakeObject(object):
-    storage = None
-
     def __init__(self, map):
         self.map = map
+        self.object_storage = self.unboxed_storage = None
 
 
-class TestMapDict(BaseTopazTest):
+class TestMapDict(object):
     @pytest.mark.parametrize("i", range(10))
     def test_simple_size_estimation(self, space, i):
-        class_node = ClassNode(i)
-        assert class_node.size_estimate() == 0
+        class_node = mapdict.ClassNode(i)
+        assert class_node.size_estimate.object_size_estimate() == 0
+        assert class_node.size_estimate.unboxed_size_estimate() == 0
 
         for j in range(1000):
             w_obj = FakeObject(class_node)
             for a in "abcdefghij"[:i]:
-                w_obj.map.add_attr(space, w_obj, a)
-        assert class_node.size_estimate() == i
+                w_obj.map = w_obj.map.add(space, mapdict.ObjectAttributeNode, a, w_obj)
+        assert class_node.size_estimate.object_size_estimate() == i
+        assert class_node.size_estimate.unboxed_size_estimate() == 0
 
     @pytest.mark.parametrize("i", range(1, 10))
     def test_avg_size_estimation(self, space, i):
-        class_node = ClassNode(i)
-        assert class_node.size_estimate() == 0
+        class_node = mapdict.ClassNode(i)
+        assert class_node.size_estimate.object_size_estimate() == 0
+        assert class_node.size_estimate.unboxed_size_estimate() == 0
 
         for j in range(1000):
             w_obj = FakeObject(class_node)
             for a in "abcdefghij"[:i]:
-                w_obj.map.add_attr(space, w_obj, a)
+                w_obj.map = w_obj.map.add(space, mapdict.ObjectAttributeNode, a, w_obj)
             w_obj = FakeObject(class_node)
             for a in "klmnopqars":
-                w_obj.map.add_attr(space, w_obj, a)
-        assert class_node.size_estimate() in [(i + 10) // 2, (i + 11) // 2]
+                w_obj.map = w_obj.map.add(space, mapdict.ObjectAttributeNode, a, w_obj)
+
+        assert class_node.size_estimate.object_size_estimate() in [(i + 10) // 2, (i + 11) // 2]
+        assert class_node.size_estimate.unboxed_size_estimate() == 0