Upgrade some divmod folding for symbolic divs (#12216)

* use const_factor() instead of arg

* add test

* change div min_max

* add tests

* add divide_by_symbolic_gcd

* add tests

* one more test

* Slice to unbind symbolic

* deal with const factor properly

* minor cleanup

* divide_by_symbolic_gcd becomes UOp.gcd and UOp.divide_exact

* add tests

* add gcd_without_const

* fix divide_exact bug

* add factor_remainder

* add tests

* fix imports

* elif -> if

* remove expectedFailure

* add more tests

* add more unwrap

* fix signature of pop_const

* remove that

* remove that
This commit is contained in:
Sieds Lykles
2025-09-17 03:00:50 +02:00
committed by GitHub
parent 328bfe6b9b
commit 158506b91e
4 changed files with 119 additions and 34 deletions
-1
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@@ -13,7 +13,6 @@ class TestSymbolic(unittest.TestCase):
assert st.shape == (x, 3)
assert st.real_strides() == (3, 1)
@unittest.expectedFailure
def test_real_strides_0(self):
st = ShapeTracker(views=(View(shape=(2, (Variable('start_pos', 1, 8)+1), 1, 1), strides=(8, 1, 0, 0), offset=0, mask=((0, 2), (0, Variable('start_pos', 1, 8)), (0, 1), (0, 1)), contiguous=False), View(shape=(2, (Variable('start_pos', 1, 8)+1)), strides=((Variable('start_pos', 1, 8)+1), 1), offset=0, mask=None, contiguous=True))) # noqa: E501
self.assertEqual(st.real_strides(), (8, None))
+58
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@@ -93,6 +93,37 @@ class TestSymbolic(unittest.TestCase):
assert idx1+idx2 is not idx2
assert idx1*idx2 is not idx2*idx1
def test_uop_gcd_method(self):
a = Variable("a", 0, 8)
b = Variable("b", 0, 8)
self.assertEqual(UOp.gcd(a, a*b, a*3).simplify(), a)
self.assertEqual(UOp.gcd(a*a*a, a*b*a, a*3*a).simplify(), a*a)
self.assertEqual(UOp.gcd(a*a*10, b*a*5, a*a*5).simplify(), a*5)
self.assertEqual(UOp.gcd(a*10, b*5, a*5).simplify(), a.const_like(5))
self.assertEqual(UOp.gcd(a, b*5, a*5).simplify(), a.const_like(1))
def test_divides_exact(self):
a = Variable("a", 1, 8)
b = Variable("b", 1, 8)
self.assertEqual((a*a*3).divide_exact(a).simplify(), a*3)
self.assertEqual((a*a*3).divide_exact(a*a*3).simplify(), a.const_like(1))
self.assertEqual((a*b*3).divide_exact(a.const_like(3)).simplify(), a*b)
self.assertEqual((a*a*3).divide_exact(a*a.const_like(-3)).simplify(), a*-1)
self.assertEqual((a*a*b*3).divide_exact(a*b).simplify(), a*3)
self.assertEqual((a*3+a*b).divide_exact(a).simplify(), b+3)
self.assertEqual((a*b*3+a*b*b).divide_exact(a*b).simplify(), b+3)
self.assertEqual((((a*-2)+14)*b).divide_exact(((a*-2)+14)).simplify(), b)
def test_divide_exact_not(self):
a = Variable("a", 1, 8)
b = Variable("b", 1, 8)
x = Variable("x", -20, 0)
self.assertEqual((a).divide_exact(b), None)
self.assertEqual((a+2).divide_exact(a), None)
self.assertEqual((x*-1).divide_exact(a), None)
self.assertEqual((a*5).divide_exact(a*10), None)
self.assertEqual((a*10-1).divide_exact(a*10), None)
def test_factorize(self):
a = Variable("a", 0, 8)
b = Variable("b", 0, 8)
@@ -450,6 +481,33 @@ class TestSymbolic(unittest.TestCase):
def test_mul_div_factor_div_neg(self):
self.helper_test_variable((Variable("a", 0, 10)*-4+4)//8, -4, 0, "(((a*-1)+1)//2)")
def test_div_symbolic_const_gcd(self):
a = Variable("a", -10, 10)
b = Variable("b", -10, 10)
d = Variable("d", 1, 10)
self.helper_test_variable((3*a+9*b)//(3*d), -40, 40, "((a+(b*3))//d)")
def test_symbolic_gcd_div(self):
a = Variable("a", -10, 10)
b = Variable("b", -10, 10)
c = Variable("c", -10, 10)
d1 = Variable("d1", 1, 10)
d2 = Variable("d2", -10, -1)
self.helper_test_variable((d1*a*b*d1)//(d1), -1000, 1000, "(a*(b*d1))")
self.helper_test_variable((d1*a*d2*b*d1)//(d1*d2), -1000, 1000, "(a*(b*d1))")
self.helper_test_variable((d1*a + b*d1)//(d1), -20, 20, "(a+b)")
self.helper_test_variable((d1*a + b*d1 + c*d1)//(d1), -30, 30, "(c+(a+b))")
self.helper_test_variable((3*a*d1 + 9*b*d1)//(3*d1*d2), -40, 40, "(((a+(b*3))//(d2*-1))*-1)")
self.helper_test_variable((3*a*d1 + 9*b*d1+3)//(3*d1*d2), -401, 399, "(((((a*d1)+((b*d1)*3))+1)//((d1*d2)*-1))*-1)")
def test_symbolic_factor_remainder_div(self):
a = Variable("a", 0, 10)
b = Variable("b", 0, 10)
d = Variable("d", 1, 10)
self.helper_test_variable((d*a+b)//d, 0, 20, "(a+(b//d))")
self.helper_test_variable((d*a*20+b)//(5*d), 0, 42, "((a*4)+(b//(d*5)))")
self.helper_test_variable((d*a*20+b*d*5+10)//(5*d), 0, 52, "((b+(a*4))+(2//d))")
def test_mod_gcd_factor_neg(self):
self.helper_test_variable((Variable("a", 0, 10)*-4+4)%8, -4, 4, "((((a*-1)+1)%2)*4)")
+18 -2
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@@ -1,6 +1,6 @@
from __future__ import annotations
from typing import Any, Callable, cast, TYPE_CHECKING, Type, Sequence
import sys, time, functools, itertools, math, operator, hashlib, os, types, pickle, pathlib, inspect, weakref
import sys, time, functools, itertools, math, operator, hashlib, os, types, pickle, pathlib, inspect, weakref, collections
from dataclasses import dataclass, field
from enum import Enum, auto
from tinygrad.uop import Ops, GroupOp
@@ -549,7 +549,23 @@ class UOp(MathTrait, metaclass=UOpMetaClass):
if (d0:=self.src[0].divides(v)) is not None: return d0 * self.src[1]
if (d1:=self.src[1].divides(v)) is not None: return self.src[0] * d1
return None # generic None if we aren't sure
def pop_const(self) -> tuple[UOp, int]: return (self.src[0], self.src[1].arg) if self.op is Ops.ADD and self.src[1].op is Ops.CONST else (self, 0)
def pop_const(self, op=Ops.ADD) -> tuple[UOp, ConstType]:
return (self.src[0], self.src[1].arg) if self.op is op and self.src[1].op is Ops.CONST else (self, identity_element(op, self.dtype))
@staticmethod
def gcd(*uops: UOp) -> UOp:
terms, factors = zip(*[(u.divides(f:=u.const_factor()),f) for u in uops])
count = functools.reduce(operator.and_, [collections.Counter(term.split_uop(Ops.MUL)) for term in terms])
return math.prod([*count.elements(), terms[0].const_like(math.gcd(*factors))]) # put the const at the top
def divide_exact(self, v:UOp) -> UOp|None:
if self is v: return self.const_like(1)
if self.op is Ops.ADD: return None if (s0:=self.src[0].divide_exact(v)) is None or (s1:=self.src[1].divide_exact(v)) is None else s0+s1
if v.op is Ops.CONST: return self.divides(v.arg)
if self.op is Ops.MUL:
(fac, const), (div_fac, div_const) = self.pop_const(Ops.MUL), v.pop_const(Ops.MUL)
new_count = collections.Counter(fac.split_uop(Ops.MUL))
new_count.subtract(div_fac.split_uop(Ops.MUL))
if const%div_const==0 and all(v>=0 for v in new_count.values()): return math.prod([*new_count.elements(), self.const_like(const//div_const)])
return None # generic None if we aren't sure
@property
def vmin(self) -> ConstType: return self._min_max[0]
@property
+43 -31
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@@ -4,7 +4,7 @@ import math, operator, struct, functools
from collections import defaultdict
from tinygrad.uop.ops import Ops, PatternMatcher, UPat, UOp, GroupOp, exec_alu
from tinygrad.dtype import ConstType, dtypes, PtrDType, AddrSpace, can_safe_cast, Invalid
from tinygrad.helpers import partition, all_same, prod, flatten, get_single_element, cdiv, cmod, CORRECT_DIVMOD_FOLDING
from tinygrad.helpers import partition, all_same, prod, flatten, get_single_element, cdiv, cmod, CORRECT_DIVMOD_FOLDING, unwrap
from tinygrad.uop.decompositions import xpow
# ******** phase 1 of symbolic used to live in ops, it's the most generic folding rules ********
@@ -164,7 +164,7 @@ def remove_nested_mod(m: UOp, x: UOp, y: UOp) -> UOp|None:
def fold_binary_numerator(d: UOp, x: UOp, y: UOp) -> UOp|None:
# we can fold if the expression has only one non-constant term and this term can only take on two values
if ((c := y.arg) < 0) or (x.dtype.count > 1): return None
if ((c := y.arg) < 0): return None
x,const = x.pop_const()
terms, factors = zip(*[(u.divides(f:=u.const_factor()),f) for u in x.split_uop(Ops.ADD)])
if len(terms)==1 and (v:=terms[0]).vmax-v.vmin == 1:
@@ -175,7 +175,7 @@ def fold_binary_numerator(d: UOp, x: UOp, y: UOp) -> UOp|None:
def fold_divmod_congruence(d: UOp, x: UOp, y: UOp) -> UOp|None:
# within a mod we can freely subtract multiples of c, we use this to see if a is congruent to an expression whose vmin/vmax are between 0 and c
if (x.vmin<0 and CORRECT_DIVMOD_FOLDING) or ((c := y.arg) < 0) or (x.dtype.count > 1): return None
if (x.vmin<0 and CORRECT_DIVMOD_FOLDING) or ((c := y.arg) < 0): return None
x,const = x.pop_const()
terms, factors = zip(*[(u.divides(f:=u.const_factor()),f) for u in x.split_uop(Ops.ADD)])
# a//c = (a-a%c)/c, if we can fold a%c, we can fold a//c
@@ -186,14 +186,28 @@ def fold_divmod_congruence(d: UOp, x: UOp, y: UOp) -> UOp|None:
def divide_by_gcd(d: UOp, x: UOp, y: UOp) -> UOp|None:
# x//y -> (x//gcd)//(y//gcd) or x%y -> gcd*(x//gcd)%(y//gcd)
terms, factors = zip(*[(u.divides(f:=u.const_factor()),f) for u in x.split_uop(Ops.ADD)])
if (gcd := math.gcd(y.arg, *factors)) == 1: return None
ret = sum(f//gcd * v for f,v in zip(factors, terms)).alu(d.op, y.const_like(y.arg//gcd))
gcd = UOp.gcd(*x.split_uop(Ops.ADD), y).simplify()
if gcd.op is Ops.CONST and gcd.arg==1: return None
ret = unwrap(x.divide_exact(gcd)).alu(d.op, unwrap(y.divide_exact(gcd)))
return ret*gcd if d.op is Ops.MOD else ret
def gcd_with_remainder(d: UOp, x: UOp, y: UOp):
# (gcd*x+r)//(gcd*d) -> (x+(r%d)//gcd)//d + r//(gcd*d)
# (gcd*x+r)%(gcd*d) -> gcd*(x+(r%d)//gcd)%d + r%gcd
# These only work for floordiv (and the corresponding remainder)! Thats why we check the sign of x,y and new_x
if ((c := y.arg) < 0) or x.vmin<0: return None
x_no_const, const = x.pop_const()
gcd = UOp.gcd(*x_no_const.split_uop(Ops.ADD), y).simplify()
assert gcd.op is Ops.CONST
if gcd.arg==1: return None
new_x = unwrap(x_no_const.divide_exact(gcd)).simplify() + (const%c)//gcd
if new_x.vmin<0: return None
ret = new_x.alu(d.op, x.ufix(c//gcd.arg))
return ret*gcd + const%gcd.arg if d.op is Ops.MOD else ret+const//c
def nest_div_by_smallest_factor(d: UOp, x: UOp, y: UOp) -> UOp|None:
# we try and nest the div and see if it allows the numerator to be simplified
if ((c := y.arg) < 0) or (x.dtype.count > 1): return None
if ((c := y.arg) < 0): return None
factors = [u.const_factor() for u in x.pop_const()[0].split_uop(Ops.ADD)]
# div is the smallest factor of the denominator (greater than 1) out of all "factors"
# TODO: there are better ways to pick `div`, this sometimes adds extra divisions
@@ -202,27 +216,22 @@ def nest_div_by_smallest_factor(d: UOp, x: UOp, y: UOp) -> UOp|None:
if (1 < div < c) and (newxs:=(newx:=(x//div)).simplify()) is not newx and x.vmin>=0 and newx.vmin>=0: return newxs//(c//div)
return None
def simplify_remainder(d: UOp, x: UOp, y: UOp) -> UOp|None:
# we try and take out the quotient and see if it allows the numerator to be simplified
if ((c := y.arg) < 0) or (x.dtype.count > 1): return None
x_no_const,const = x.pop_const()
terms, factors = zip(*[(u.divides(f:=u.const_factor()),f) for u in x_no_const.split_uop(Ops.ADD)])
quotients, remainders = zip(*[divmod(f, c) for f in factors])
gcd = math.gcd(c, *remainders) # gcd without const!
if const%c==const and gcd==1 and not any(r==0 or (r!=f and d.op is Ops.MOD) for r,f in zip(remainders, factors)): return None
quo, rem = x.const_like(const//c), x.const_like((const%c)//gcd)
for q,r,f,v in zip(quotients, remainders, factors, terms):
if d.op is Ops.IDIV and r!=0:
rem += f//gcd * v
else:
rem += r//gcd * v
quo += q * v
# if numerator before/after is negative, and it has remainder, don't simplify because C divmod is different from python divmod.
if (x.vmin < 0 or rem.vmin < 0) and remainders: return None
if d.op is Ops.MOD: return gcd*(rem % (c//gcd)) + const%gcd
return rem//(c//gcd)+quo
def factor_remainder(d: UOp, x: UOp, y: UOp) -> UOp|None:
# (d*x+y)//d -> x+y//d or (d*x+y)%d
# for mod we go further and take the remainder of all factors to reduce their size
# These only work for floordiv (and the corresponding remainder)! Thats why we check the sign of x,y and new_x
if y.vmin<0 or x.vmin<0: return None
quo, rem = [], []
for u in x.split_uop(Ops.ADD):
if (q:=u.divide_exact(y)) is not None: quo.append(q)
# if this is mod and y is a const, we can make the remainder factor sm
elif d.op is Ops.MOD and y.op is Ops.CONST and (c:=u.const_factor())%y.arg!=c:
rem.append(u.divides(c)*(c%y.arg))
quo.append(u.const_like(0)) # we append this so we can check if something changed
else: rem.append(u)
new_x = sum(rem)+x.const_like(0)
if len(quo)==0 or new_x.vmin<0: return None
return new_x%y if d.op is Ops.MOD else new_x//y+sum(quo)
def gep_through_wmma(gep:UOp, wmma:UOp):
out_sz = prod(x[1] for x in wmma.arg[6][-1])
@@ -334,14 +343,17 @@ symbolic = symbolic_simple+commutative+PatternMatcher([
(UPat(Ops.RANGE, src=UPat.var("end"), name="r")%UPat.var("end"), lambda r,end: r),
(UPat(Ops.RANGE, src=UPat.var("end"), name="r")//UPat.var("end"), lambda r,end: r.const_like(0)),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.var("y"))), cancel_divmod),
(UPat.var("x") // UPat.var("d"), lambda x,d: -(x//(-d)) if d.vmax < 0 else None),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.cvar("y", vec=False))), fold_binary_numerator),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.cvar("y", vec=False))), fold_divmod_congruence),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.cvar("y", vec=False))), divide_by_gcd),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.var("y"))), divide_by_gcd),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.cvar("y", vec=False))), gcd_with_remainder),
(UPat(Ops.MOD, dtypes.index, name="m", src=(UPat.var("x"), UPat.cvar("y", vec=False))), remove_nested_mod),
(UPat((Ops.IDIV), dtypes.index, name="d", src=(UPat.var("x"), UPat.cvar("y", vec=False))), nest_div_by_smallest_factor),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.cvar("y", vec=False))), simplify_remainder),
(UPat.var("x") // UPat.var("d"), lambda x,d: -(x//(-d)) if d.vmax < 0 else None),
(UPat((Ops.IDIV, Ops.MOD), dtypes.index, name="d", src=(UPat.var("x"), UPat.var("y"))), factor_remainder),
(UPat.var("x") // UPat.var("d"), lambda x,d: -((-x)//d) if x.vmax <=0 else None),
((UPat.var("x", dtypes.index)+UPat.cvar("c", vec=False)).named("n")//UPat.cvar("d", vec=False),
lambda x,c,n,d: ((x+c.arg%d.arg)//d + c.arg//d.arg) if c.arg%d.arg!=c.arg and x.vmin>=0 and n.vmin>=0 and d.arg>0 else None),
((UPat.var("x", dtypes.index)+UPat.cvar("c", vec=False)).named("n")//UPat.cvar("d", vec=False),
lambda x,c,n,d: (-(-(c.arg%d.arg + x - (d.arg-1))//d) + c.arg//d.arg) if x.vmax<=0 and n.vmin>=0 and d.arg>0 else None),
# ** mod **