def _extract_time_invariants(self,
cluster,
template,
with_cse=True,
costmodel=None,
**kwargs):
"""
Extract time-invariant subexpressions, and assign them to temporaries.
"""
make = lambda: Scalar(name=template(), dtype=cluster.dtype).indexify()
rule = iq_timeinvariant(cluster.trace)
costmodel = costmodel or (lambda e: estimate_cost(e) > 0)
processed, found = xreplace_constrained(cluster.exprs, make, rule,
costmodel)
if with_cse:
leaves = [i for i in processed if i not in found]
# Search for common sub-expressions amongst them (and only them)
found = common_subexprs_elimination(found, make)
# Some temporaries may be droppable at this point
processed = compact_temporaries(found, leaves)
return cluster.rebuild(processed)
def test_xreplace_constrained_time_invariants(tu, tv, tw, ti0, ti1, t0, t1,
exprs, expected):
exprs = EVAL(exprs, tu, tv, tw, ti0, ti1, t0, t1)
make = lambda i: Scalar(name='r%d' % i).indexify()
processed, found = xreplace_constrained(
exprs, make, iq_timeinvariant(TemporariesGraph(exprs)),
lambda i: estimate_cost(i) > 0)
assert len(found) == len(expected)
assert all(str(i.rhs) == j for i, j in zip(found, expected))
def test_xreplace_constrained_time_invariants(tu, tv, tw, ti0, ti1, t0, t1,
exprs, expected):
exprs = EVAL(exprs, tu, tv, tw, ti0, ti1, t0, t1)
counter = generator()
make = lambda: Scalar(name='r%d' % counter()).indexify()
processed, found = xreplace_constrained(exprs, make,
iq_timeinvariant(FlowGraph(exprs)),
lambda i: estimate_cost(i) > 0)
assert len(found) == len(expected)
assert all(str(i.rhs) == j for i, j in zip(found, expected))
def _extract_time_invariants(self, cluster, template, with_cse=True, **kwargs):
"""
Extract time-invariant subexpressions, and assign them to temporaries.
"""
make = lambda: Scalar(name=template(), dtype=cluster.dtype).indexify()
rule = iq_timeinvariant(cluster.trace)
costmodel = lambda e: estimate_cost(e) > 0
processed, found = xreplace_constrained(cluster.exprs, make, rule, costmodel)
if with_cse:
leaves = [i for i in processed if i not in found]
# Search for common sub-expressions amongst them (and only them)
found = common_subexprs_elimination(found, make)
# Some temporaries may be droppable at this point
processed = compact_temporaries(found, leaves)
return cluster.rebuild(processed)
