[pypy-svn] pypy arm-backend-2: Do not generate instructions for operations without side effects and an unused result

[bivab]

Author: David Schneider <david.schneider at picle.org>
Branch: arm-backend-2
Changeset: r40666:e0fa01427ac3
Date: 2011-01-14 11:55 +0100
http://bitbucket.org/pypy/pypy/changeset/e0fa01427ac3/

Log:	Do not generate instructions for operations without side effects and
	an unused result

diff --git a/pypy/jit/backend/arm/assembler.py b/pypy/jit/backend/arm/assembler.py
--- a/pypy/jit/backend/arm/assembler.py
+++ b/pypy/jit/backend/arm/assembler.py
@@ -465,7 +465,11 @@
             regalloc.position = i
             op = operations[i]
             opnum = op.getopnum()
-            if self.can_merge_with_next_guard(op, i, operations):
+            if op.has_no_side_effect() and op.result not in regalloc.longevity:
+                i += 1
+                regalloc.possibly_free_vars_for_op(op)
+                continue
+            elif self.can_merge_with_next_guard(op, i, operations):
                 arglocs = regalloc.operations_with_guard[opnum](regalloc, op,
                                         operations[i+1], fcond)
                 fcond = self.operations_with_guard[opnum](self, op,