From 661f58514353a360d18a4548d21331a7f3bab568 Mon Sep 17 00:00:00 2001
From: Matt Wala <wala1@illinois.edu>
Date: Wed, 1 Feb 2017 23:10:43 -0600
Subject: [PATCH] CSE: Don't pull things out of derivatives, Subs (closes #14).
---
sumpy/codegen.py | 22 ----------------------
sumpy/cse.py | 25 ++++++++++++++++++-------
test/test_cse.py | 30 +++++++++++++++++-------------
3 files changed, 35 insertions(+), 42 deletions(-)
diff --git a/sumpy/codegen.py b/sumpy/codegen.py
index 01385642..8eef9892 100644
--- a/sumpy/codegen.py
+++ b/sumpy/codegen.py
@@ -63,24 +63,6 @@ _SPECIAL_FUNCTION_NAMES = frozenset(dir(sym.functions))
class SympyToPymbolicMapper(SympyToPymbolicMapperBase):
- def __init__(self, assignments):
- self.assignments = dict(
- (sym.Symbol(name), value) for name, value in assignments)
- self.derivative_cse_names = set()
-
- def map_Derivative(self, expr): # noqa
- # Sympy has picked up the habit of picking arguments out of derivatives
- # and pronounce them common subexpressions. Me no like. Undo it, so
- # that the bessel substitutor further down can do its job.
-
- if expr.expr.is_Symbol:
- # These will get removed, because loopy wont' be able to deal
- # with them--they contain undefined placeholder symbols.
- self.derivative_cse_names.add(expr.expr.name)
-
- return prim.Derivative(self.rec(
- expr.expr.subs(self.assignments)),
- tuple(v.name for v in expr.variables))
def not_supported(self, expr):
if isinstance(expr, int):
@@ -676,10 +658,6 @@ def to_loopy_insns(assignments, vector_names=set(), pymbolic_expr_maps=[],
# convert from sympy
sympy_conv = SympyToPymbolicMapper(assignments)
assignments = [(name, sympy_conv(expr)) for name, expr in assignments]
- assignments = [
- (name, expr) for name, expr in assignments
- if name not in sympy_conv.derivative_cse_names
- ]
assignments = kill_trivial_assignments(assignments, retain_names)
diff --git a/sumpy/cse.py b/sumpy/cse.py
index a073983a..6a0270e7 100644
--- a/sumpy/cse.py
+++ b/sumpy/cse.py
@@ -66,7 +66,8 @@ DAMAGE.
# }}}
-from sumpy.symbolic import Basic, Mul, Add, Pow, Symbol, _coeff_isneg
+from sumpy.symbolic import (
+ Basic, Mul, Add, Pow, Symbol, _coeff_isneg, Derivative, Subs)
from sympy.core.compatibility import iterable
from sympy.utilities.iterables import numbered_symbols
@@ -81,6 +82,10 @@ Common subexpression elimination
"""
+# Don't CSE child nodes of these classes.
+CSE_NO_DESCEND_CLASSES = (Derivative, Subs)
+
+
# {{{ cse pre/postprocessing
def preprocess_for_cse(expr, optimizations):
@@ -352,6 +357,9 @@ def opt_cse(exprs):
if expr.is_Atom:
return
+ if isinstance(expr, CSE_NO_DESCEND_CLASSES):
+ return
+
if iterable(expr):
for item in expr:
find_opts(item)
@@ -443,7 +451,10 @@ def tree_cse(exprs, symbols, opt_subs=None):
if expr in opt_subs:
expr = opt_subs[expr]
- args = expr.args
+ if isinstance(expr, CSE_NO_DESCEND_CLASSES):
+ args = ()
+ else:
+ args = expr.args
for arg in args:
find_repeated(arg)
@@ -481,11 +492,11 @@ def tree_cse(exprs, symbols, opt_subs=None):
if expr in opt_subs:
expr = opt_subs[expr]
- new_args = tuple(rebuild(arg) for arg in expr.args)
- if isinstance(expr, Unevaluated) or new_args != expr.args:
- new_expr = expr.func(*new_args)
- else:
- new_expr = expr
+ new_expr = expr
+ if not isinstance(expr, CSE_NO_DESCEND_CLASSES):
+ new_args = tuple(rebuild(arg) for arg in expr.args)
+ if isinstance(expr, Unevaluated) or new_args != expr.args:
+ new_expr = expr.func(*new_args)
if orig_expr in to_eliminate:
try:
diff --git a/test/test_cse.py b/test/test_cse.py
index c9f0264e..4f957aaa 100644
--- a/test/test_cse.py
+++ b/test/test_cse.py
@@ -189,7 +189,7 @@ def test_multiple_expressions():
rsubsts, _ = cse(reversed(l))
assert substs == [(x0, -z), (x1, x + x0), (x2, x0 + y)]
assert rsubsts == [(x0, -z), (x1, x0 + y), (x2, x + x0)]
- assert reduced == [f(x1,x2), x1, x2]
+ assert reduced == [f(x1, x2), x1, x2]
l = [w*y + w + x + y + z, w*x*y]
assert cse(l) == ([(x0, w*y)], [w + x + x0 + y + z, x*x0])
assert cse([x + y, x + y + z]) == ([(x0, x + y)], [x0, z + x0])
@@ -202,27 +202,31 @@ def test_issue_4203():
assert cse(sin(x**x)/x**x) == ([(x0, x**x)], [sin(x0)/x0])
-@sympyonly
-def test_dont_cse_tuples():
+def test_dont_cse_subs():
from sumpy.symbolic import Subs
f = Function("f")
g = Function("g")
name_val, (expr,) = cse(
- Subs(f(x, y), (x, y), (0, 1))
- + Subs(g(x, y), (x, y), (0, 1)))
+ Subs(f(x, y), (x, y), (0, x + y))
+ + Subs(g(x, y), (x, y), (0, x + y)))
assert name_val == []
- assert expr == (Subs(f(x, y), (x, y), (0, 1))
- + Subs(g(x, y), (x, y), (0, 1)))
+ assert expr == Subs(f(x, y), (x, y), (0, x + y)) + \
+ Subs(g(x, y), (x, y), (0, x + y))
- name_val, (expr,) = cse(
- Subs(f(x, y), (x, y), (0, x + y))
- + Subs(g(x, y), (x, y), (0, x + y)))
- assert name_val == [(x0, x + y)]
- assert expr == Subs(f(x, y), (x, y), (0, x0)) + \
- Subs(g(x, y), (x, y), (0, x0))
+def test_dont_cse_derivative():
+ from sumpy.symbolic import Derivative
+ f = Function("f")
+
+ # FIXME
+ deriv = Derivative(f(x+y), (x,)) if USE_SYMENGINE else Derivative(f(x+y), x)
+
+ name_val, (expr,) = cse(x + y + deriv)
+
+ assert name_val == []
+ assert expr == x + y + deriv
def test_pow_invpow():
--
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