[pypy-svn] pypy arm-backend-2: (arigo, david) when generating code for a call, force the variable stored in r0 to be spilled if the call has a return value and ensure a register can not be bound to two boxes after a call.

[bivab]

Author: David Schneider <david.schneider at picle.org>
Branch: arm-backend-2
Changeset: r42034:95434737666e
Date: 2011-02-16 14:20 +0100
http://bitbucket.org/pypy/pypy/changeset/95434737666e/

Log:	(arigo, david) when generating code for a call, force the variable
	stored in r0 to be spilled if the call has a return value and ensure
	a register can not be bound to two boxes after a call.

diff --git a/pypy/jit/backend/arm/opassembler.py b/pypy/jit/backend/arm/opassembler.py
--- a/pypy/jit/backend/arm/opassembler.py
+++ b/pypy/jit/backend/arm/opassembler.py
@@ -268,9 +268,13 @@
             regalloc.before_call(save_all_regs=spill_all_regs)
         else:
             if result:
-                # XXX maybe move instance check to llsupport/regalloc
-                if reg_args > 0 and isinstance(args[0], Box) and regalloc.stays_alive(args[0]):
-                    regalloc.force_spill_var(args[0])
+                # XXX hack if the call has a result force the value in r0 to be
+                # spilled
+                if reg_args == 0 or (isinstance(args[0], Box) and
+                        regalloc.stays_alive(args[0])):
+                    t = TempBox()
+                    regalloc.force_allocate_reg(t, selected_reg=regalloc.call_result_location(t))
+                    regalloc.possibly_free_var(t)
                 self.mc.PUSH([reg.value for reg in r.caller_resp][1:])
             else:
                 self.mc.PUSH([reg.value for reg in r.caller_resp])

diff --git a/pypy/jit/backend/llsupport/regalloc.py b/pypy/jit/backend/llsupport/regalloc.py
--- a/pypy/jit/backend/llsupport/regalloc.py
+++ b/pypy/jit/backend/llsupport/regalloc.py
@@ -324,6 +324,8 @@
         """
         self._check_type(v)
         r = self.call_result_location(v)
+        if not we_are_translated():
+            assert r not in self.reg_bindings.values()
         self.reg_bindings[v] = r
         self.free_regs = [fr for fr in self.free_regs if fr is not r]
         return r