[pypy-commit] pypy disable-unroll-for-short-loops: try to attack the problem differently, a bit unclear how to test the beast

[fijal]

Author: Maciej Fijalkowski <fijall at gmail.com>
Branch: disable-unroll-for-short-loops
Changeset: r77925:655b7c16bafd
Date: 2015-06-05 21:20 +0200
http://bitbucket.org/pypy/pypy/changeset/655b7c16bafd/

Log:	try to attack the problem differently, a bit unclear how to test the
	beast

diff --git a/rpython/jit/metainterp/compile.py b/rpython/jit/metainterp/compile.py
--- a/rpython/jit/metainterp/compile.py
+++ b/rpython/jit/metainterp/compile.py
@@ -104,34 +104,6 @@
 # ____________________________________________________________
 
 
-def disable_unrolling_if_loop_too_long(loop, metainterp):
-    threshold = metainterp.jitdriver_sd.warmstate.disable_unrolling_threshold
-    if len(loop.operations) < threshold:
-        return False
-    # now we need to patch label, like in simplify.py
-    last_op = loop.operations[-1]
-    descr = last_op.getdescr()
-    assert isinstance(descr, TargetToken)
-    descr = descr.targeting_jitcell_token
-    assert isinstance (descr, JitCellToken)
-    last_op = last_op.copy_and_change(rop.JUMP)
-    if not descr.target_tokens:
-        # fish the first label
-        for op in loop.operations:
-            if op.getopnum() == rop.LABEL:
-                target_token = op.getdescr()
-                break
-        else:
-            assert False, "can't find a label"
-        assert isinstance(target_token, TargetToken)
-        assert target_token.targeting_jitcell_token is descr
-        last_op.setdescr(target_token)
-    else:
-        assert len(descr.target_tokens) == 1
-        last_op.setdescr(descr.target_tokens[0])
-    loop.operations[-1] = last_op
-    return True
-
 def compile_loop(metainterp, greenkey, start,
                  inputargs, jumpargs,
                  full_preamble_needed=True,
@@ -177,7 +149,7 @@
     if part.quasi_immutable_deps:
         loop.quasi_immutable_deps.update(part.quasi_immutable_deps)
     if part.operations[-1].getopnum() == rop.LABEL:
-        if not disable_unrolling_if_loop_too_long(part, metainterp):
+        if start_state is not None:
             inliner = Inliner(inputargs, jumpargs)
             part.quasi_immutable_deps = None
             part.operations = [part.operations[-1]] + \
diff --git a/rpython/jit/metainterp/optimizeopt/unroll.py b/rpython/jit/metainterp/optimizeopt/unroll.py
--- a/rpython/jit/metainterp/optimizeopt/unroll.py
+++ b/rpython/jit/metainterp/optimizeopt/unroll.py
@@ -154,6 +154,19 @@
 
         loop.operations = self.optimizer.get_newoperations()
         if export_state:
+            jd_sd = self.optimizer.jitdriver_sd
+            threshold = jd_sd.warmstate.disable_unrolling_threshold
+            if 1 or len(loop.operations) > threshold:
+                if loop.operations[0].getopnum() == rop.LABEL:
+                    # abandoning unrolling, too long
+                    new_descr = stop_label.getdescr()
+                    if loop.operations[0].getopnum() == rop.LABEL:
+                        new_descr = loop.operations[0].getdescr()
+                    stop_label = stop_label.copy_and_change(rop.JUMP,
+                                        descr=new_descr)
+                    self.optimizer.send_extra_operation(stop_label)
+                    loop.operations = self.optimizer.get_newoperations()
+                    return None
             final_state = self.export_state(stop_label)
         else:
             final_state = None