Author: Berkin Ilbeyi <[email protected]>
Branch: fold-arith-ops
Changeset: r77450:ed4d8276d497
Date: 2015-05-21 10:29 -0400
http://bitbucket.org/pypy/pypy/changeset/ed4d8276d497/
Log: remove more code duplication, add comments
diff --git a/rpython/jit/metainterp/optimizeopt/intbounds.py
b/rpython/jit/metainterp/optimizeopt/intbounds.py
--- a/rpython/jit/metainterp/optimizeopt/intbounds.py
+++ b/rpython/jit/metainterp/optimizeopt/intbounds.py
@@ -129,6 +129,13 @@
v1 = self.getvalue(arg1)
v2 = self.getvalue(arg2)
+ # Optimize for addition chains in code "b = a + 1; c = b + 1" by
+ # detecting the int_add chain, and swapping with "b = a + 1;
+ # c = a + 2". If b is not used elsewhere, the backend eliminates
+ # it.
+
+ # either v1 or v2 can be a constant, swap the arguments around if
+ # v1 is the constant
if v1.is_constant():
arg1, arg2 = arg2, arg1
v1, v2 = v2, v1
@@ -139,18 +146,22 @@
pass
else:
if prod_op.getopnum() == rop.INT_ADD:
- prod_v1 = self.getvalue(prod_op.getarg(0))
- prod_v2 = self.getvalue(prod_op.getarg(1))
+ prod_arg1 = prod_op.getarg(0)
+ prod_arg2 = prod_op.getarg(1)
+ prod_v1 = self.getvalue(prod_arg1)
+ prod_v2 = self.getvalue(prod_arg2)
+
+ # same thing here: prod_v1 or prod_v2 can be a
+ # constant
+ if prod_v1.is_constant():
+ prod_arg1, prod_arg2 = prod_arg2, prod_arg1
+ prod_v1, prod_v2 = prod_v2, prod_v1
if prod_v2.is_constant():
sum = v2.box.getint() + prod_v2.box.getint()
+ # the sum might not be a valid int if the values
+ # added are very large
if is_valid_int(sum):
- arg1 = prod_op.getarg(0)
- arg2 = ConstInt(sum)
- op = op.copy_and_change(rop.INT_ADD, args=[arg1,
arg2])
- elif prod_v1.is_constant():
- sum = arg2.getint() + prod_v1.box.getint()
- if is_valid_int(sum):
- arg1 = prod_op.getarg(1)
+ arg1 = prod_arg1
arg2 = ConstInt(sum)
op = op.copy_and_change(rop.INT_ADD, args=[arg1,
arg2])
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