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tinygrad/test/null/test_graph_rewrite.py
2026-08-19 11:18:05 -04:00

367 lines
15 KiB
Python

import unittest, math
from tinygrad import dtypes
from tinygrad.helpers import all_same, Context
from tinygrad.uop.ops import GroupOp, UOp, Ops, PatternMatcher, TrackedPatternMatcher, UPat
from test.helpers import full_rewrite
from hypothesis import given, strategies as strat
# Helper function to apply the graph rewrite
@Context(SPEC=0)
def apply_rewrite(expr):
return full_rewrite(expr.sink()).src[0]
def const_value(uop:UOp):
if uop.op is Ops.CAST: uop = uop.src[0]
assert uop.op is Ops.CONST
return uop.val
class TestModuloAndDivisionFolding(unittest.TestCase):
def test_graph_rewrite_div_folding_bug(self):
lhs = UOp.stack(*(UOp.special(32, 'lidx0'),)*4) + UOp.const((0, 256, 512, 768))
rhs = UOp.const((2,)*4)
unopt = lhs<rhs
opt = apply_rewrite(unopt)
print(unopt)
print(opt)
if opt.op is Ops.STACK: self.assertFalse(all_same(opt.src))
class TestEdgeCasesAndSpecialOperations(unittest.TestCase):
def test_full_graph_rewrite_transcendental_edge_cases(self):
optimized_sink = full_rewrite(UOp.const(-1.0).log2().sink(UOp.const(0.0).reciprocal()))
optimized_log2_neg, optimized_recip_zero = optimized_sink.src
log2_neg, recip_zero = const_value(optimized_log2_neg), const_value(optimized_recip_zero)
self.assertTrue(math.isnan(log2_neg), f"Expected NaN for log2(-1.0), got {log2_neg}")
self.assertTrue(math.isinf(recip_zero) and recip_zero > 0, f"Expected +inf for reciprocal(0.0), got {recip_zero}")
class TestGEPAndVectorizeRewrite(unittest.TestCase):
def test_gep_single_element_extraction(self):
# GEP on a vector dtype to extract a single element
base_vector = UOp.const((1.0, 2.0, 3.0, 4.0))
self.assertIs(apply_rewrite(base_vector.index(2)), apply_rewrite(base_vector.src[2]))
def test_gep_tuple_extraction(self):
# GEP on a vector dtype to extract multiple elements as a vector
base_vector = UOp.const((1.0, 2.0, 3.0, 4.0))
self.assertIs(apply_rewrite(UOp.stack(*[base_vector.index(i) for i in (2, 3)])),
apply_rewrite(UOp.stack(base_vector.src[2], base_vector.src[3])))
def test_vectorize_multiple_elements(self):
# Vectorizing multiple elements using GEP
base_vector = UOp.const((5.0, 10.0, 15.0, 20.0))
vectorized_uop = UOp.stack(*(base_vector.index(i) for i in range(4)))
self.assertIs(apply_rewrite(vectorized_uop), apply_rewrite(base_vector))
import inspect
from tinygrad.uop.ops import graph_rewrite, _substitute, rewrite_group
from tinygrad.uop.symbolic import symbolic_simple
class TestBottomUpRewrite(unittest.TestCase):
def test_const_folding(self):
a = UOp.const(5)
ret = (a*3) + (a*7)
gt = graph_rewrite(ret, symbolic_simple)
ret = graph_rewrite(ret, symbolic_simple, bottom_up=True)
self.assertIs(gt, ret)
# normally .substitute would be fine, but it's not tracked
@rewrite_group()
def named_substitute(name:str, uop:UOp, rel:dict[UOp, UOp]): return graph_rewrite(uop, _substitute, rel, bottom_up=True)
def substitute(uop:UOp, rel:dict[UOp, UOp]): return named_substitute(inspect.stack()[1].function, uop, rel)
class TestSubstitute(unittest.TestCase):
# these work because the substituted things don't have parents
def test_simple(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
ret = a + 4
ret = substitute(ret, {a:b})
self.assertIs(ret, b+4)
def test_double(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
c = UOp.variable('c', 0, 10)
ret = (a + 4) + b
ret = substitute(ret, {a:c, b:c})
self.assertIs(ret, (c + 4) + c)
def test_diamond(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
ret = (a + 4) + (a + 5)
ret = substitute(ret, {a:b})
self.assertIs(ret, (b + 4) + (b + 5))
# this works because there's nothing above the substituted node
def test_sin(self):
a = UOp.variable('a', 0, 10, dtype=dtypes.float)
b = UOp.variable('b', 0, 10, dtype=dtypes.float)
ret = a.sin().sin()
ret = substitute(ret, {a.sin():b})
self.assertIs(ret, b.sin())
def test_sin_to_sqrt(self):
a = UOp.variable('a', 0, 10, dtype=dtypes.float)
n1 = a.sin()
ret = n1.sin()
ret = substitute(ret, {a.sin():a.sqrt()})
self.assertIs(ret, a.sqrt().sin())
def test_double_sin_to_sqrt(self):
a = UOp.variable('a', 0, 10, dtype=dtypes.float)
n1 = a.sin()
ret = n1.sin()
# NOTE: this would work if it had gone in the opposite order
ret = substitute(ret, {a.sin():a.sqrt(), n1.sin():n1.sqrt()})
self.assertIs(ret, a.sqrt().sqrt())
def test_tagged_replace(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
ret = (a+4).replace(tag=1)
ret = substitute(ret, {a:b})
# the srcs are rewritten but we keep tag
self.assertIs(ret, (b+4).replace(tag=1))
matchers = strat.sampled_from([PatternMatcher, TrackedPatternMatcher])
class TestRecurse(unittest.TestCase):
@given(matchers)
def test_no_inf_loop(self, PatternMatcher):
a = UOp.variable('a', 0, 10)
pm = PatternMatcher([(UPat(Ops.PARAM, name="x"), lambda x: x)])
graph_rewrite(a, pm)
@given(matchers)
def test_no_inf_loop_bottom_up(self, PatternMatcher):
a = UOp.variable('a', 0, 10)
pm = PatternMatcher([(UPat(Ops.PARAM, name="x"), lambda x: x)])
graph_rewrite(a, pm, bottom_up=True)
def test_inf_loop(self):
a = UOp.const(3)
pm = PatternMatcher([
(UPat(Ops.CONST, arg=3, name="x"), lambda x: UOp.const(4, x.dtype)),
(UPat(Ops.CONST, arg=4, name="x"), lambda x: UOp.const(3, x.dtype)),
])
with self.assertRaises(RuntimeError):
graph_rewrite(a, pm)
def test_inf_loop_bottom_up(self):
a = UOp.const(3)
pm = PatternMatcher([
(UPat(Ops.CONST, arg=3, name="x"), lambda x: UOp.const(4, x.dtype)),
(UPat(Ops.CONST, arg=4, name="x"), lambda x: UOp.const(3, x.dtype)),
])
with self.assertRaises(RuntimeError):
graph_rewrite(a, pm, bottom_up=True)
def bidir_append(ctx, x, b): ctx.append((x.val if x.op is Ops.CONST else "+", b))
class TestBidirectional(unittest.TestCase):
def test_simple(self):
a = UOp.const(1)
b = UOp.const(2)
c = a + b
pm = PatternMatcher([ (UPat(GroupOp.All, name="x"), lambda ctx,x: bidir_append(ctx, x, False)) ])
bpm = PatternMatcher([ (UPat(GroupOp.All, name="x"), lambda ctx,x: bidir_append(ctx, x, True)) ])
ctx_list = []
graph_rewrite(c, pm, ctx=ctx_list, bpm=bpm)
self.assertListEqual(ctx_list, [('+', True), (1, True), (1, False), (2, True), (2, False), ('+', False)])
class TestStopEarly(unittest.TestCase):
def test_stop_early(self):
a = UOp.const(3)
b = UOp.const(4)
c = a+b
cn = UOp.const(7)
d = UOp.const(2)
def visit_const(c:UOp):
print(f"visit {c.val}")
assert c.val not in (3,4)
pm_cvisit = PatternMatcher([(UPat(Ops.CONST, name="c"), visit_const),])
ret = (c+d).substitute({c:cn}, extra_pm=pm_cvisit)
assert ret == cn+d
class TestWalkRewrite(unittest.TestCase):
"""Tests for graph_rewrite with walk=True (MLIR Walk Pattern Rewrite Driver semantics).
walk=True gives a single-pass traversal that does NOT revisit or re-traverse into rewritten subtrees.
Supports both top-down (default) and bottom-up (bottom_up=True) modes."""
# *** top-down walk (default): process children first, then try pm on rebuilt node ***
def test_walk_topdown_simple_substitute(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
ret = graph_rewrite(a + 4, _substitute, {a:b}, walk=True)
self.assertIs(ret, b+4)
def test_walk_topdown_does_not_traverse_into_replacement(self):
"""Top-down walk: replacement subtrees are NOT re-entered."""
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
c = UOp.variable('c', 0, 10)
d = UOp.variable('d', 0, 10)
# a is replaced by b+c, but b inside the replacement is NOT further substituted to d
ret_walk = graph_rewrite(a + 4, _substitute, {a:b+c, b:d}, walk=True)
self.assertIs(ret_walk, (b+c)+4)
# contrast: greedy bottom_up WOULD replace b inside the replacement
ret_greedy = graph_rewrite(a + 4, _substitute, {a:b+c, b:d}, bottom_up=True)
self.assertIs(ret_greedy, (d+c)+4)
def test_walk_topdown_no_fixed_point(self):
"""A bouncing pattern applies once and stops instead of looping."""
a = UOp.const(3)
pm = PatternMatcher([
(UPat(Ops.CONST, arg=3, name="x"), lambda x: UOp.const(4, x.dtype)),
(UPat(Ops.CONST, arg=4, name="x"), lambda x: UOp.const(3, x.dtype)),
])
with self.assertRaises(RuntimeError):
graph_rewrite(a, pm, bottom_up=True)
ret = graph_rewrite(a, pm, walk=True)
self.assertIs(ret, UOp.const(4))
def test_walk_topdown_rewrites_children(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
c = UOp.variable('c', 0, 10)
ret = graph_rewrite((a + 4) + (b + 5), _substitute, {a:c, b:c}, walk=True)
self.assertIs(ret, (c + 4) + (c + 5))
def test_walk_topdown_diamond(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
ret = graph_rewrite((a + 4) + (a + 5), _substitute, {a:b}, walk=True)
self.assertIs(ret, (b + 4) + (b + 5))
def test_walk_topdown_children_rewritten_before_parent(self):
"""Top-down walk processes children first: child substitution changes the rebuilt parent."""
a = UOp.variable('a', 0, 10, dtype=dtypes.float)
n1 = a.sin() # sin(a)
ret = n1.sin() # sin(sin(a))
# sin(a)->sqrt(a) fires first (child), parent rebuilds to sin(sqrt(a)), which doesn't match sin(sin(a)) in dvars
ret_walk = graph_rewrite(ret, _substitute, {a.sin():a.sqrt(), n1.sin():n1.sqrt()}, walk=True)
self.assertIs(ret_walk, a.sqrt().sin())
def test_walk_topdown_self_referential_replacement(self):
"""Replacement containing the replaced node works without infinite recursion."""
a = UOp.variable('a', 0, 10, dtype=dtypes.float)
ret = graph_rewrite(a.sin() + 4, _substitute, {a.sin(): a.sin().sqrt()}, walk=True)
self.assertIs(ret, a.sin().sqrt() + 4)
def test_walk_topdown_visit_order(self):
"""Top-down walk fires pm after children are processed (post-order)."""
visited = []
def track_visit(ctx, x):
ctx.append(x.val if x.op is Ops.CONST else x.op)
return None
pm = PatternMatcher([(UPat(GroupOp.All, name="x"), track_visit)])
a = UOp.const(1)
b = UOp.const(2)
graph_rewrite(a + b, pm, ctx=visited, walk=True)
self.assertEqual(visited, [1, 2, Ops.ADD])
# *** bottom-up walk: try bpm on node first, skip children if it matches ***
def test_walk_bottomup_simple_substitute(self):
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
ret = graph_rewrite(a + 4, _substitute, {a:b}, bottom_up=True, walk=True)
self.assertIs(ret, b+4)
def test_walk_bottomup_does_not_traverse_into_replacement(self):
"""Bottom-up walk: replacement subtrees are NOT entered."""
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
c = UOp.variable('c', 0, 10)
d = UOp.variable('d', 0, 10)
ret = graph_rewrite(a + 4, _substitute, {a:b+c, b:d}, bottom_up=True, walk=True)
self.assertIs(ret, (b+c)+4)
def test_walk_bottomup_parent_match_skips_children(self):
"""Bottom-up walk matches parent first: if it matches, children are never visited."""
a = UOp.variable('a', 0, 10, dtype=dtypes.float)
n1 = a.sin()
ret = n1.sin() # sin(sin(a))
# sin(sin(a)) matches n1.sin()->n1.sqrt() immediately, children never visited, sin(a) inside replacement untouched
ret_walk = graph_rewrite(ret, _substitute, {a.sin():a.sqrt(), n1.sin():n1.sqrt()}, bottom_up=True, walk=True)
self.assertIs(ret_walk, a.sin().sqrt())
def test_walk_bottomup_no_fixed_point(self):
"""Bottom-up walk also applies once per node, no fixed-point iteration."""
a = UOp.const(3)
pm = PatternMatcher([
(UPat(Ops.CONST, arg=3, name="x"), lambda x: UOp.const(4, x.dtype)),
(UPat(Ops.CONST, arg=4, name="x"), lambda x: UOp.const(3, x.dtype)),
])
ret = graph_rewrite(a, pm, bottom_up=True, walk=True)
self.assertIs(ret, UOp.const(4))
def test_walk_bottomup_visit_order(self):
"""Bottom-up walk fires bpm before descending (pre-order)."""
visited = []
def track_visit(ctx, x):
ctx.append(x.val if x.op is Ops.CONST else x.op)
return None
pm = PatternMatcher([(UPat(GroupOp.All, name="x"), track_visit)])
a = UOp.const(1)
b = UOp.const(2)
graph_rewrite(a + b, pm, ctx=visited, bottom_up=True, walk=True)
# bpm fires on each node before children: +, 1, 2
self.assertEqual(visited, [Ops.ADD, 1, 2])
def test_walk_bottomup_unmatched_falls_through_to_children(self):
"""Bottom-up walk: if bpm doesn't match a node, its children are still processed."""
a = UOp.variable('a', 0, 10)
b = UOp.variable('b', 0, 10)
c = UOp.variable('c', 0, 10)
# only a is in dvars, not a+4. bpm won't match a+4, so it descends and finds a.
ret = graph_rewrite((a + 4) + (b + 5), _substitute, {a:c, b:c}, bottom_up=True, walk=True)
self.assertIs(ret, (c + 4) + (c + 5))
# *** bidirectional walk: bpm fires before children, pm fires after rebuild ***
def test_walk_bidirectional_visit_order(self):
"""Bidirectional walk: bpm fires pre-order, pm fires post-order."""
visited = []
def bpm_visit(ctx, x):
ctx.append((x.val if x.op is Ops.CONST else x.op, "bpm"))
return None
def pm_visit(ctx, x):
ctx.append((x.val if x.op is Ops.CONST else x.op, "pm"))
return None
bpm = PatternMatcher([(UPat(GroupOp.All, name="x"), bpm_visit)])
pm = PatternMatcher([(UPat(GroupOp.All, name="x"), pm_visit)])
a = UOp.const(1)
b = UOp.const(2)
graph_rewrite(a + b, pm, ctx=visited, bpm=bpm, walk=True)
# bpm fires pre-order, pm fires post-order
self.assertEqual(visited, [
(Ops.ADD, "bpm"), (1, "bpm"), (1, "pm"), (2, "bpm"), (2, "pm"), (Ops.ADD, "pm"),
])
def test_walk_bidirectional_bpm_short_circuits(self):
"""If bpm matches, children are skipped and pm never fires on that node."""
visited = []
def bpm_match(ctx, x):
ctx.append((x.val if x.op is Ops.CONST else x.op, "bpm"))
# rewrite const(1) -> const(10), short-circuiting its subtree
if x.op is Ops.CONST and x.val == 1: return UOp.const(10, x.dtype)
return None
def pm_match(ctx, x):
ctx.append((x.val if x.op is Ops.CONST else x.op, "pm"))
return None
bpm = PatternMatcher([(UPat(GroupOp.All, name="x"), bpm_match)])
pm = PatternMatcher([(UPat(GroupOp.All, name="x"), pm_match)])
a = UOp.const(1)
b = UOp.const(2)
ret = graph_rewrite(a + b, pm, ctx=visited, bpm=bpm, walk=True)
# bpm matches const(1) and short-circuits it, so pm never fires on const(1)
self.assertNotIn((1, "pm"), visited)
# but pm still fires on const(2) and the rebuilt ADD
self.assertIn((2, "pm"), visited)
self.assertIs(ret, UOp.const(10) + b)
if __name__ == '__main__':
unittest.main()