[pypy-svn] r67103 - in pypy/branch/pyjitpl5/pypy/jit/backend/x86: . test

[fijal at codespeak.net]

Author: fijal
Date: Sun Aug 23 11:42:04 2009
New Revision: 67103

Modified:
   pypy/branch/pyjitpl5/pypy/jit/backend/x86/regalloc.py
   pypy/branch/pyjitpl5/pypy/jit/backend/x86/test/test_regalloc.py
Log:
A tiny performance fix about not using registers for moving away
vars. Should not matter too much but at least was easy


Modified: pypy/branch/pyjitpl5/pypy/jit/backend/x86/regalloc.py
==============================================================================
--- pypy/branch/pyjitpl5/pypy/jit/backend/x86/regalloc.py	(original)
+++ pypy/branch/pyjitpl5/pypy/jit/backend/x86/regalloc.py	Sun Aug 23 11:42:04 2009
@@ -475,8 +475,13 @@
 
     def move_variable_away(self, v, prev_loc):
         reg = None
-        loc = self.stack_loc(v)
-        self.Store(v, prev_loc, loc)
+        if self.free_regs:
+            loc = self.free_regs.pop()
+            self.reg_bindings[v] = loc
+            self.Load(v, prev_loc, loc)
+        else:
+            loc = self.stack_loc(v)
+            self.Store(v, prev_loc, loc)
 
     def force_result_in_reg(self, result_v, v, forbidden_vars):
         """ Make sure that result is in the same register as v

Modified: pypy/branch/pyjitpl5/pypy/jit/backend/x86/test/test_regalloc.py
==============================================================================
--- pypy/branch/pyjitpl5/pypy/jit/backend/x86/test/test_regalloc.py	(original)
+++ pypy/branch/pyjitpl5/pypy/jit/backend/x86/test/test_regalloc.py	Sun Aug 23 11:42:04 2009
@@ -130,6 +130,20 @@
                                               None), None)
         regalloc._check_invariants()
 
+    def test_move_away_does_not_spill(self):
+        regalloc = RegAlloc(MockAssembler(), DummyTree())
+        regalloc.position = 0
+        resbox = BoxInt()
+        box = BoxInt()
+        regalloc.reg_bindings = {box: eax}
+        regalloc.free_regs = [ebx, ecx, edx, esi, edi]
+        regalloc._check_invariants()
+        regalloc.longevity = {resbox: (0, 1), box: (0, 1)}
+        regalloc.consider_int_add(ResOperation(rop.INT_ADD, [box, ConstInt(1)],
+                                               resbox), None)
+        regalloc._check_invariants()
+        assert len(regalloc.assembler.stores) == 0
+
 class BaseTestRegalloc(object):
     cpu = CPU(None, None)