def function_limit_bound (fname, split):
p = functions[fname].as_problem (problem.Problem)
p.do_loop_analysis (skipInnerLoopCheck = True)
[p_split] = [n for n in p.loop_heads () if split in p.loop_body (n)]
splits = [n for n in p.loop_body (p_split) if p.loop_splittables[n]]
# doesn't cover a really odd case, but I think it's good enough
for n in splits:
if p.nodes[n].kind == 'Call':
if function_limit (p.nodes[n].fname) != None:
return (function_limit (p.nodes[n].fname), 'FunctionLimit')
return None
def function_limit_bound(fname, split):
p = functions[fname].as_problem(problem.Problem)
p.do_analysis()
cuts = [n for n in p.loop_body(split) if p.nodes[n].kind == "Call" if function_limit(p.nodes[n].fname) != None]
if not cuts:
return None
graph = p.mk_node_graph(p.loop_body(split))
# it is not possible to iterate the loop without visiting a bounded
# function. naively, this sets the limit to the sum of all the possible
# bounds, plus one because we can enter the loop a final time without
# visiting any function call site yet.
if logic.divides_loop(graph, set(cuts)):
fnames = set([p.nodes[n].fname for n in cuts])
return (sum([function_limit(f) for f in fnames]) + 1, "FunctionLimit")
def function_limit_bound(fname, split):
p = functions[fname].as_problem(problem.Problem)
p.do_analysis()
cuts = [
n for n in p.loop_body(split) if p.nodes[n].kind == 'Call'
if function_limit(p.nodes[n].fname) != None
]
if not cuts:
return None
graph = p.mk_node_graph(p.loop_body(split))
# it is not possible to iterate the loop without visiting a bounded
# function. naively, this sets the limit to the sum of all the possible
# bounds, plus one because we can enter the loop a final time without
# visiting any function call site yet.
if logic.divides_loop(graph, set(cuts)):
fnames = set([p.nodes[n].fname for n in cuts])
return (sum([function_limit(f) for f in fnames]) + 1, 'FunctionLimit')
def get_bound_super_ctxt_inner(split, call_ctxt, no_splitting=(False, None)):
first_f = trace_refute.identify_function([], (call_ctxt + [split])[:1])
call_sites = all_call_sites(first_f)
if function_limit(first_f) == 0:
return (0, "FunctionLimit")
safe_call_sites = [cs for cs in call_sites if ctxt_within_function_limits([cs] + call_ctxt)]
if call_sites and not safe_call_sites:
return (0, "FunctionLimit")
if len(call_ctxt) < 3 and len(safe_call_sites) == 1:
call_ctxt2 = list(safe_call_sites) + call_ctxt
if call_ctxt_computable(split, call_ctxt2):
return get_bound_super_ctxt(split, call_ctxt2)
fname = trace_refute.identify_function(call_ctxt, [split])
bound = function_limit_bound(fname, split)
if bound:
return bound
bound = get_bound_ctxt(split, call_ctxt)
if bound:
return bound
if no_splitting[0]:
assert no_splitting[1], no_splitting
no_splitting[1][0] = True
return None
# try to split over potential call sites
if len(call_ctxt) >= 3:
return None
if len(call_sites) == 0:
# either entry point or nonsense
return None
if [call_site for call_site in safe_call_sites if not call_ctxt_computable(split, [call_site] + call_ctxt)]:
return None
anc_bounds = [
get_bound_super_ctxt(split, [call_site] + call_ctxt, no_splitting=True) for call_site in safe_call_sites
]
if None in anc_bounds:
return None
(bound, kind) = max(anc_bounds)
return (bound, "MergedBound")
def get_bound_super_ctxt_inner(split, call_ctxt, no_splitting=(False, None)):
first_f = trace_refute.identify_function([], (call_ctxt + [split])[:1])
call_sites = all_call_sites(first_f)
if function_limit(first_f) == 0:
return (0, 'FunctionLimit')
safe_call_sites = [
cs for cs in call_sites
if ctxt_within_function_limits([cs] + call_ctxt)
]
if call_sites and not safe_call_sites:
return (0, 'FunctionLimit')
if len(call_ctxt) < 3 and len(safe_call_sites) == 1:
call_ctxt2 = list(safe_call_sites) + call_ctxt
if call_ctxt_computable(split, call_ctxt2):
trace('using unique calling context %s' % str((split, call_ctxt2)))
return get_bound_super_ctxt(split, call_ctxt2)
fname = trace_refute.identify_function(call_ctxt, [split])
bound = function_limit_bound(fname, split)
if bound:
return bound
bound = get_bound_ctxt(split, call_ctxt)
if bound:
return bound
trace('no bound found immediately.')
if no_splitting[0]:
assert no_splitting[1], no_splitting
no_splitting[1][0] = True
trace('cannot split by context (recursion).')
return None
# try to split over potential call sites
if len(call_ctxt) >= 3:
trace('cannot split by context (context depth).')
return None
if len(call_sites) == 0:
# either entry point or nonsense
trace('cannot split by context (reached top level).')
return None
problem_sites = [
call_site for call_site in safe_call_sites
if not call_ctxt_computable(split, [call_site] + call_ctxt)
]
if problem_sites:
trace('cannot split by context (issues in %s).' % problem_sites)
return None
anc_bounds = [
get_bound_super_ctxt(split, [call_site] + call_ctxt, no_splitting=True)
for call_site in safe_call_sites
]
if None in anc_bounds:
return None
(bound, kind) = max(anc_bounds)
return (bound, 'MergedBound')
