outer

test/test_fold.py

@@ -0,0 +1,31 @@
+import numpy as np
+import unittest
+from tinygrad import Tensor, UOp
+from tinygrad.uop.ops import AxisType
+
+class TestFold(unittest.TestCase):
+  def test_reduce_add(self):
+    a = Tensor.randn(10, 10).realize()
+    a_red = a.sum(axis=1)
+    np.testing.assert_allclose(a_red.numpy(), a.numpy().sum(axis=1), atol=1e-6)
+
+  def test_fold_add(self):
+    a = Tensor.randn(10, 10).realize()
+    init = Tensor.zeros(10, 1).contiguous()
+    a_red = (init+a).fold(init).reshape(10)
+    np.testing.assert_allclose(a_red.numpy(), a.numpy().sum(axis=1), atol=1e-6)
+
+  #@unittest.skip("no outer fold yet")
+  def test_fold_matmul(self):
+    vec = Tensor.randn(1, 10).realize()
+    mats = Tensor.randn(3, 10, 10).realize()
+    np_mats = mats.numpy()
+    np_ref = ((vec.numpy() @ np_mats[0]) @ np_mats[1]) @ np_mats[2]
+
+    i = UOp.range(3, -1, AxisType.OUTER)
+    out = (vec @ mats[i]).contiguous().fold(vec, i)
+
+    np.testing.assert_allclose(out.numpy(), np_ref, atol=1e-6)
+
+if __name__ == '__main__':
+  unittest.main()

tinygrad/codegen/late/devectorizer.py

@@ -308,9 +308,19 @@ def reduce_to_acc(ctx:ReduceContext, red:UOp):
   if len(reduce_range) == 0: return ret
   return acc.after(acc.index(UOp.const(dtypes.int, 0)).store(ret).end(*reduce_range)).index(UOp.const(dtypes.int, 0))
 
+def fold_to_store(x:UOp):
+  _, acc, ranges = x.src[0], x.src[1], x.src[2:]
+  assert acc.op is Ops.INDEX
+  buf = acc.src[0]
+  ret = x.substitute({buf: buf.rtag().after(*ranges)}).substitute({buf.rtag(): buf})
+  base, acc, ranges = ret.src[0], ret.src[1], ret.src[2:]
+  return buf.after(acc.store(base).end(*ranges)).index(acc.src[1])
+
 pm_reduce = PatternMatcher([
-  # REDUCE -> DEFINE_ACC+ASSIGN
+  # REDUCE -> DEFINE_ACC+STORE
   (UPat(Ops.REDUCE, name="red"), reduce_to_acc),
+  # FOLD -> STORE
+  (UPat(Ops.FOLD, name="x"), fold_to_store),
   # tensor core built in accumulate
   (UPat(Ops.WMMA, name="wmma") + UPat.var("add"),
     lambda add, wmma: UOp(wmma.op, wmma.dtype, (wmma.src[0], wmma.src[1], wmma.src[2]+add), wmma.arg)),

tinygrad/codegen/opt/postrange.py

@@ -2,7 +2,8 @@ from __future__ import annotations
 import math, itertools
 from collections import defaultdict
 from typing import cast, Final
-from tinygrad.uop.ops import PatternMatcher, UPat, Ops, UOp, KernelInfo, graph_rewrite, AxisType, ssimplify, GroupOp, axis_letters, axis_colors
+from tinygrad.uop.ops import PatternMatcher, UPat, Ops, UOp, KernelInfo, graph_rewrite, AxisType, ssimplify, GroupOp
+from tinygrad.uop.ops import axis_letters, axis_colors, axis_to_pos
 from tinygrad.device import Buffer
 from tinygrad.dtype import dtypes, ImageDType
 from tinygrad.helpers import colored, BEAM, getenv, DEBUG, to_function_name, NOOPT, argsort, round_up, prod, merge_dicts, get_single_element, flatten
@@ -12,10 +13,6 @@ from tinygrad.renderer import Renderer
 
 remove_tags = PatternMatcher([(UPat(GroupOp.All, name="x"), lambda x: x.replace(tag=None) if x.tag is not None else None)])
 
-# NOTE: LOCAL and GROUP_REDUCE have the same priority. the order here matters
-axis_to_pos = {AxisType.LOOP: -1, AxisType.THREAD: 0, AxisType.GLOBAL: 0, AxisType.WARP: 1, AxisType.LOCAL: 2, AxisType.UPCAST: 3,
-               AxisType.GROUP_REDUCE: 2, AxisType.REDUCE: 4, AxisType.UNROLL: 5}
-
 class Scheduler:
   def __init__(self, ast:UOp, ren:Renderer):
     self.ast, self.ren = ast, ren

tinygrad/schedule/indexing.py

@@ -54,7 +54,7 @@ def create_bufferize_and_index_based_on_ranges(ctx:IndexingContext, x:UOp):
   if x.op in {Ops.BUFFERIZE, Ops.INDEX}: return None
   if x.op is Ops.AFTER and x.src[1].op is Ops.KERNEL: return None
   new_srcs = []
-  for s in x.src:
+  for i,s in enumerate(x.src):
     new_src = s
     if s.op in {Ops.BUFFER, Ops.BUFFER_VIEW, Ops.MSTACK, Ops.MSELECT} or (s.op is Ops.AFTER and s.src[1].op is Ops.KERNEL):
       if x in ctx.range_map: new_src = new_src.index(*ctx.range_map[x][0])
@@ -65,7 +65,9 @@ def create_bufferize_and_index_based_on_ranges(ctx:IndexingContext, x:UOp):
       # None in the device assigns it a number later
       opts = BufferizeOpts(device=s.device) if len(ctx.range_map[s][1]) == len(realized_ranges) else BufferizeOpts(None, AddrSpace.LOCAL)
       new_src = UOp(Ops.BUFFERIZE, s.dtype, src=(new_src,)+closed_ranges, arg=opts, tag=s.tag if opts.addrspace == AddrSpace.GLOBAL else None)
-      if x in ctx.range_map: new_src = new_src.index(*[r for i,r in enumerate(ctx.range_map[x][0]) if i in realized_ranges])
+      if x in ctx.range_map:
+        # for scan we use the output ranges on the 2nd arg
+        new_src = new_src.index(*[r for i,r in enumerate(ctx.range_map[x][int(x.op is Ops.FOLD and i == 1)]) if i in realized_ranges])
     new_srcs.append(new_src)
   # NOTE: do we need this?
   return x.replace(src=tns) if x.src != (tns:=tuple(new_srcs)) else None
@@ -84,6 +86,13 @@ def convert_reduce_axis_to_reduce_with_ranges(ctx:IndexingContext, x:UOp):
   ctx.range_map[ret] = ctx.range_map[x]
   return ret
 
+def add_ranges_to_scan(ctx:IndexingContext, x:UOp):
+  if x not in ctx.range_map: return None
+  new_ranges = [r for r,ar in zip(*ctx.range_map[x]) if r is not ar and r not in x.src]
+  ret = x.replace(src=x.src+tuple(new_ranges))
+  ctx.range_map[ret] = ctx.range_map[x]
+  return ret
+
 def remove_movement_op_after_rangeify(ctx:IndexingContext, x:UOp):
   if x in ctx.range_map or x.src[0].op is Ops.INDEX: return x.src[0]
 
@@ -97,6 +106,8 @@ def add_third_op_to_assign_to_track_shape(ctx:IndexingContext, assign:UOp):
 pm_apply_rangeify = PatternMatcher([
   # REDUCE_AXIS -> REDUCE
   (UPat(Ops.REDUCE_AXIS, name="x"), convert_reduce_axis_to_reduce_with_ranges),
+  # SCAN -> SCAN (with new ranges)
+  (UPat(Ops.FOLD, name="x"), add_ranges_to_scan),
   # PAD -> WHERE
   (UPat(Ops.PAD, name="x"), convert_pad_to_where_to_keep_behavior_local),
   # add third op to assign
@@ -244,6 +255,9 @@ def run_rangeify(tsink:UOp, debug:bool=False) -> tuple[UOp, IndexingContext]:
     # REDUCE_AXIS creates ranges for the axes it is reducing
     if x.op is Ops.REDUCE_AXIS:
       rngs = tuple(rctx.new_range(s, axistype=AxisType.REDUCE) if i in x.arg[1] else r for i,(r,s) in enumerate(zip(rngs, x.src[0].shape)))
+    if x.op is Ops.FOLD:
+      rngs = tuple(rctx.new_range(s, axistype=AxisType.FOLD) if resolve(x.src[1].shape[i] == 1) else r \
+                   for i,(r,s) in enumerate(zip(rngs, x.src[0].shape)))
 
     if debug:
       realized_ranges = rctx.realize_map.get(x, None)

tinygrad/schedule/rangeify.py

@@ -396,6 +396,7 @@ def handle_after(ctx:LocalAddBufferContext, after:UOp):
   return buf
 
 def renumber_range(ctx:LocalAddBufferContext, r:UOp):
+  if r.arg[-1] == AxisType.OUTER: return None
   if r.tag != (): return None
   ret = r.replace(arg=(ctx.range,)+r.arg[1:], tag=None)
   ctx.range += 1
@@ -469,7 +470,10 @@ pm_add_range_tags = PatternMatcher([
 ])
 
 def split_store(ctx:list[UOp], x:UOp) -> UOp|None:
-  if len(x.ranges): return None
+  if len([r for r in x.ranges if r.arg[-1] != AxisType.OUTER]): return None
+
+  # ends of outer range don't go in kernels
+  if x.op is Ops.END and x.src[1].op is Ops.RANGE and x.src[1].arg[-1] == AxisType.OUTER: return None
 
   # local kernel rewrite
   lctx = LocalAddBufferContext()

tinygrad/tensor.py

@@ -1509,6 +1509,9 @@ class Tensor(OpMixin):
 
   # ***** reduce ops *****
 
+  def fold(self, init:Tensor, *ranges:UOp) -> Tensor:
+    return self._apply_uop(UOp.fold, init, extra_args=ranges)
+
   def _reduce(self, op:Ops, axis:int|Sequence[int]|None=None, keepdim=False) -> Tensor:
     axis = tuple(self._resolve_dim(x) for x in (range(self.ndim) if axis is None else make_tuple(axis, 1)))
     if self.ndim == 0: axis = ()

tinygrad/uop/__init__.py

@@ -92,6 +92,9 @@ class Ops(FastEnum):
   # reduce
   REDUCE_AXIS = auto(); REDUCE = auto(); ALLREDUCE = auto()
 
+  # scan
+  FOLD = auto()
+
   # errors/placeholders
   REWRITE_ERROR = auto(); SENTINEL = auto()
 

tinygrad/uop/ops.py

@@ -13,14 +13,20 @@ if TYPE_CHECKING:
 
 class AxisType(Enum):
   def __repr__(self): return str(self)
-  GLOBAL = auto(); WARP = auto(); LOCAL = auto(); LOOP = auto(); GROUP_REDUCE = auto(); REDUCE = auto(); UPCAST = auto(); UNROLL = auto() # noqa: E702
-  THREAD = auto()
+  GLOBAL = auto(); WARP = auto(); LOCAL = auto(); LOOP = auto(); GROUP_REDUCE = auto(); REDUCE = auto(); FOLD = auto() # noqa: E702
+  UPCAST = auto(); UNROLL = auto() # noqa: E702
+  THREAD = auto(); OUTER = auto() # noqa: E702
 axis_letters = {AxisType.GLOBAL: "g", AxisType.THREAD: "t", AxisType.LOCAL: "l", AxisType.WARP: "w", AxisType.LOOP: "L", AxisType.UPCAST: "u",
-                AxisType.GROUP_REDUCE: "G", AxisType.REDUCE: "R", AxisType.UNROLL: "r"}
+                AxisType.GROUP_REDUCE: "G", AxisType.REDUCE: "R", AxisType.FOLD: "F", AxisType.UNROLL: "r", AxisType.OUTER: "O"}
 axis_colors = {AxisType.GLOBAL: "blue", AxisType.THREAD: "BLUE", AxisType.LOCAL: "cyan", AxisType.WARP: "CYAN", AxisType.LOOP: "WHITE",
-               AxisType.UPCAST: "yellow", AxisType.GROUP_REDUCE: "RED", AxisType.REDUCE: "red", AxisType.UNROLL: "magenta"}
+               AxisType.UPCAST: "yellow", AxisType.GROUP_REDUCE: "RED", AxisType.REDUCE: "red", AxisType.FOLD: "red", AxisType.UNROLL: "magenta",
+               AxisType.OUTER: "green"}
 
-range_start = {Ops.BUFFERIZE: 1, Ops.REDUCE: 1, Ops.STORE: 2, Ops.WMMA: 3, Ops.END: 1}
+# NOTE: LOCAL and GROUP_REDUCE have the same priority. the order here matters
+axis_to_pos = {AxisType.LOOP: -1, AxisType.THREAD: 0, AxisType.GLOBAL: 0, AxisType.WARP: 1, AxisType.LOCAL: 2, AxisType.UPCAST: 3,
+               AxisType.GROUP_REDUCE: 2, AxisType.FOLD: 4, AxisType.REDUCE: 5, AxisType.UNROLL: 6, AxisType.OUTER: -2}
+
+range_start = {Ops.BUFFERIZE: 1, Ops.REDUCE: 1, Ops.STORE: 2, Ops.WMMA: 3, Ops.END: 1, Ops.FOLD: 2}
 
 # https://en.wikipedia.org/wiki/Identity_element
 def identity_element(op:Ops, dt:DType) -> ConstType: return dtypes.as_const({Ops.ADD:0, Ops.MUL:1, Ops.MAX:dtypes.min(dt)}[op], dt)
@@ -213,6 +219,10 @@ class UOp(OpMixin, metaclass=UOpMetaClass):
       case Ops.BUFFERIZE: return tuple([int(r.vmax+1) for r in self.src[1:]])
       case Ops.DEFINE_GLOBAL | Ops.DEFINE_LOCAL | Ops.DEFINE_REG: return (self.ptrdtype.size,)
 
+      # shape of init
+      case Ops.FOLD:
+        return self.src[1]._shape
+
       # passthrough ops
       case Ops.REDUCE | Ops.MSTACK | Ops.MSELECT | Ops.DETACH | Ops.CONTIGUOUS | Ops.CONTIGUOUS_BACKWARD | Ops.AFTER | Ops.END:
         return self.src[0]._shape
@@ -437,6 +447,7 @@ class UOp(OpMixin, metaclass=UOpMetaClass):
     assert self.dtype.scalar() is dtypes.index, "Can only call get_valid on index dtype"
     return self.src[0] if self.op is Ops.WHERE and self.src[2].arg is Invalid else UOp.const(dtypes.bool, self.arg is not Invalid)
   def reduce(self, *src:UOp, **kwargs): return UOp(Ops.REDUCE, kwargs.pop('dtype', self.dtype), src=(self,)+src, **kwargs)
+  def fold(self, *src:UOp, **kwargs): return UOp(Ops.FOLD, self.dtype, (self,)+src, **kwargs)
 
   def is_contiguous(self):
     # TODO: this is is_realized

tinygrad/uop/spec.py

@@ -40,6 +40,9 @@ shared_spec = PatternMatcher([
     rng.dtype == x.dtype and isinstance(rng.arg, tuple) and len(rng.arg) >= 2 and \
       all(isinstance(ra, int) for ra in rng.arg[0:-1]) and isinstance(rng.arg[-1], AxisType)),
   (UPat(Ops.INDEX, src=(UPat(),), allow_any_len=True, name="x"), lambda x: all(y.dtype == dtypes.index for y in x.src[1:]) or None),
+
+  # FOLD, 2 ops + ranges
+  (UPat(Ops.FOLD, src=(UPat(), UPat()), allow_any_len=True, name="x"), lambda x: all(y.dtype == dtypes.index for y in x.src[2:])),
 ])
 
 # ***** UOp spec in the Tensor graph *****
@@ -172,7 +175,7 @@ kernel_spec = PatternMatcher([
   # bufferize can be on anything
   (UPat(Ops.BUFFERIZE, src=(UPat(),), allow_any_len=True, name="x"), lambda x: True),
 
-  # reduce must be on ranges
+  # reduce/fold must be on ranges
   (UPat(Ops.REDUCE, src=(UPat(),), allow_any_len=True, name="x"), lambda x: all(y.dtype == dtypes.index for y in x.src[1:])),
 ])+movement_ops+shared_codegen_spec+shared_spec
 

tinygrad/viz/serve.py

@@ -17,7 +17,7 @@ from tinygrad.dtype import dtypes
 uops_colors = {Ops.LOAD: "#ffc0c0", Ops.STORE: "#87CEEB", Ops.CONST: "#e0e0e0", Ops.VCONST: "#e0e0e0", Ops.REDUCE: "#FF5B5B",
                Ops.DEFINE_GLOBAL:"#cb9037", **{x:"#f2cb91" for x in {Ops.DEFINE_LOCAL, Ops.DEFINE_REG}}, Ops.REDUCE_AXIS: "#FF6B6B",
                Ops.RANGE: "#c8a0e0", Ops.ASSIGN: "#909090", Ops.BARRIER: "#ff8080", Ops.IF: "#c8b0c0", Ops.SPECIAL: "#c0c0ff",
-               Ops.INDEX: "#cef263", Ops.WMMA: "#efefc0", Ops.MULTI: "#f6ccff", Ops.KERNEL: "#3e7f55",
+               Ops.INDEX: "#cef263", Ops.WMMA: "#efefc0", Ops.MULTI: "#f6ccff", Ops.KERNEL: "#3e7f55", Ops.FOLD: "#FF7B7B",
                **{x:"#D8F9E4" for x in GroupOp.Movement}, **{x:"#ffffc0" for x in GroupOp.ALU}, Ops.THREEFRY:"#ffff80",
                Ops.BUFFER_VIEW: "#E5EAFF", Ops.BUFFER: "#B0BDFF", Ops.COPY: "#a040a0",
                Ops.ALLREDUCE: "#ff40a0", Ops.MSELECT: "#d040a0", Ops.MSTACK: "#d040a0", Ops.CONTIGUOUS: "#FFC14D",