From 9513f025c5e1b581a6b10aa2b7b88822ce8ddbc3 Mon Sep 17 00:00:00 2001
From: qazal <77887910+Qazalin@users.noreply.github.com>
Date: Mon, 29 Sep 2025 14:16:31 +0300
Subject: [PATCH] apply multi before rangeify (#12298)

* it doesn't realize it when i reshape

* cleaner graph

* map out

* REDUCE_AXIS also gives the wrong answer

* maybe

* work

* back here

* try

* more

* refactor tests

* check MultiBuffer

* or copy

* fine with this

* don't need graph_rewrite_map in rangeify
---
 test/test_multitensor.py      | 11 +++++++++++
 tinygrad/schedule/multi.py    |  5 ++++-
 tinygrad/schedule/rangeify.py |  8 +-------
 tinygrad/tensor.py            |  5 +++++
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/test/test_multitensor.py b/test/test_multitensor.py
index 86159ba375..b688edde61 100644
--- a/test/test_multitensor.py
+++ b/test/test_multitensor.py
@@ -54,6 +54,17 @@ class TestMultiTensor(unittest.TestCase):
       assert lb.shape == (128,)
     (X + X).realize()
 
+  def _test_shard_op(self, op, out, n=4):
+    t = Tensor.ones(n).contiguous().realize().shard(devices_2, 0)
+    r = op(t).realize()
+    assert t.uop.is_realized, "shard didn't realize"
+    self.assertEqual(r.tolist(), out)
+  def test_shard_reshape(self): self._test_shard_op(lambda t:t.reshape(2, 2), [[1.,1.],[1.,1.]])
+  def test_shard_elementwise(self): self._test_shard_op(lambda t:(t+t).reshape(2, 2), [[2.,2.],[2.,2.]])
+  def test_shard_reduce(self):
+    self._test_shard_op(lambda t:t.reshape(2, 3).sum(axis=1), [3.,3.], n=6)
+    self._test_shard_op(lambda t:t.reshape(2, 3).sum(axis=0), [2.,2.,2.], n=6)
+
   def test_shard_not_multiple(self):
     X = Tensor.ones(256).contiguous().realize()
     with self.assertRaises(RuntimeError):
diff --git a/tinygrad/schedule/multi.py b/tinygrad/schedule/multi.py
index 7c695db824..a1cfe18c1a 100644
--- a/tinygrad/schedule/multi.py
+++ b/tinygrad/schedule/multi.py
@@ -1,7 +1,7 @@
 from typing import cast, TypeVar
 import functools, itertools, operator
 from tinygrad.helpers import all_same, all_int, prod, DEBUG, RING, getenv, unwrap
-from tinygrad.uop.ops import Ops, UOp, sint, PatternMatcher, UPat, GroupOp, resolve
+from tinygrad.uop.ops import Ops, UOp, sint, PatternMatcher, UPat, GroupOp, resolve, track_rewrites, graph_rewrite_map
 from tinygrad.shape.shapetracker import ShapeTracker
 from tinygrad.device import Device
 
@@ -239,3 +239,6 @@ multi_pm = PatternMatcher([
   (UPat((Ops.CAST, Ops.BITCAST, Ops.CONTIGUOUS, Ops.DETACH, Ops.CONTIGUOUS_BACKWARD, Ops.FUSE),
         src=(UPat(Ops.MULTI, name="multi"), ), name="root"), passthrough_multi),
 ])+replace_allreduce
+
+@track_rewrites()
+def get_multi_map(big_sink:UOp) -> dict[UOp, UOp]: return graph_rewrite_map(big_sink, multi_pm)
diff --git a/tinygrad/schedule/rangeify.py b/tinygrad/schedule/rangeify.py
index d283bddd46..4581981850 100644
--- a/tinygrad/schedule/rangeify.py
+++ b/tinygrad/schedule/rangeify.py
@@ -2,11 +2,9 @@ from typing import Any, cast
 import functools, operator
 from dataclasses import dataclass, field
 from tinygrad.dtype import dtypes, PtrDType, ImageDType, AddrSpace
-from tinygrad.uop.ops import PatternMatcher, UPat, Ops, UOp, resolve, GroupOp, RewriteNotReady, _substitute, ssimplify, graph_rewrite_map
+from tinygrad.uop.ops import PatternMatcher, UPat, Ops, UOp, resolve, GroupOp, RewriteNotReady, _substitute, ssimplify
 from tinygrad.uop.symbolic import sym, symbolic_simple
 from tinygrad.helpers import argsort, prod, all_same, pluralize, getenv, RANGEIFY, Context, flatten, dedup
-from tinygrad.schedule.multi import multi_pm
-
 from tinygrad.schedule.kernelize import Kernel
 from tinygrad.uop.ops import track_rewrites, graph_rewrite, identity_element, sint, AxisType
 
@@ -594,10 +592,6 @@ def get_rangeify_map(sink:UOp) -> dict[UOp, UOp]:
   uop_list: list[UOp] = []
   tsink = graph_rewrite(sink, add_tags, ctx=uop_list, bottom_up=True, name="number the uops")
 
-  # HACKS: handle multi with graph_rewrite_map in order to not have to add all the tag logic to multi
-  msink = graph_rewrite_map(tsink, multi_pm, name="multi")
-  tsink = msink[tsink].substitute({v:v.rtag(k.tag) for k,v in msink.items() if v.tag is None and k.tag is not None})
-
   tsink = graph_rewrite(tsink, earliest_rewrites, name="earliest rewrites")
   realize_map: dict[UOp, UOp] = {}
   graph_rewrite(tsink, do_realize, ctx=realize_map, name="Input Graph")
diff --git a/tinygrad/tensor.py b/tinygrad/tensor.py
index fe15acb2ec..4ceb9576f3 100644
--- a/tinygrad/tensor.py
+++ b/tinygrad/tensor.py
@@ -16,6 +16,7 @@ from tinygrad.engine.realize import run_schedule
 from tinygrad.engine.memory import memory_planner
 from tinygrad.engine.schedule import ScheduleItem, create_schedule_with_vars
 from tinygrad.schedule.rangeify import get_rangeify_map
+from tinygrad.schedule.multi import get_multi_map
 from tinygrad.schedule.kernelize import get_kernelize_map
 
 # *** all in scope Tensors are here. this gets relevant UOps ***
@@ -241,6 +242,10 @@ class Tensor(MathTrait):
     # verify Tensors match the spec
     if __debug__: type_verify(list(big_sink.toposort()), tensor_uop_spec)
 
+    if RANGEIFY and any(isinstance(x._device, tuple) for x in big_sink.toposort()):
+      _apply_map_to_tensors(get_multi_map(big_sink), "Apply Multi Map")
+      big_sink = UOp.sink(*flatten([x.uop.src if x.uop.op is Ops.MULTI else [x.uop] for x in (self,)+lst]))
+
     becomes_map = get_rangeify_map(big_sink) if RANGEIFY else get_kernelize_map(big_sink)
     _apply_map_to_tensors(becomes_map, name="Apply Kernelize Map")
     return self