From 2c3e3559eb08da8fe70cd77012826d12b012e25f Mon Sep 17 00:00:00 2001
From: chenyu <chenyu@fastmail.com>
Date: Mon, 9 Feb 2026 09:19:46 -0500
Subject: [PATCH] remove a contiguous in basic setitem (#14640)

handled in rangeify
---
 tinygrad/schedule/rangeify.py | 7 +++++++
 tinygrad/tensor.py            | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/tinygrad/schedule/rangeify.py b/tinygrad/schedule/rangeify.py
index 94250460e3..00d471e520 100644
--- a/tinygrad/schedule/rangeify.py
+++ b/tinygrad/schedule/rangeify.py
@@ -33,6 +33,10 @@ pm_mops = PatternMatcher([
 # *****************
 # 0. do some cleanup rewrites, mostly copied from the old stuff
 
+def collapse_nested_assign(assign:UOp, target:UOp, src:UOp):
+  """nested ASSIGN to the same buffer (e.g. __iadd__ in __setitem__): collapse the redundant outer ASSIGN"""
+  if src.src[0].base is target.base: return src if src.src[0] is target else assign.replace(src=(target, src.src[1]))
+
 def assign_to_contiguous(assign:UOp, target:UOp, src:UOp):
   if (t := target.base).op is Ops.BUFFER or (t.op is Ops.MSTACK and all(s.op is Ops.BUFFER for s in t.src)): return None
   return src.f(Ops.CONTIGUOUS, tag=assign.tag)
@@ -132,6 +136,9 @@ earliest_rewrites = mop_cleanup+PatternMatcher([
 
   # ** assign rules **
 
+  # collapse nested ASSIGN to the same buffer (e.g. __iadd__ in __setitem__)
+  (UPat(Ops.ASSIGN, src=(UPat(name="target"), UPat(Ops.ASSIGN, name="src")), name="assign"), collapse_nested_assign),
+
   # move bitcast from assign target to source: a.bitcast(X).assign(src) -> a.assign(src.bitcast(a.dtype))
   (UPat(Ops.ASSIGN, src=(UPat(Ops.BITCAST, src=(UPat(name="target"),)), UPat(name="src")), name="assign"),
    lambda assign, target, src: target.assign(src.bitcast(target.dtype)).replace(tag=assign.tag)),
diff --git a/tinygrad/tensor.py b/tinygrad/tensor.py
index 79d9f382a6..0dcaa91097 100644
--- a/tinygrad/tensor.py
+++ b/tinygrad/tensor.py
@@ -1291,7 +1291,7 @@ class Tensor(OpMixin):
     else: # basic setitem
       self.realize()
       if not self.uop.is_writable_view(): raise RuntimeError("setitem target must be a writable view backed by a buffer")
-      v = v.cast(res.dtype)._broadcast_to(_broadcast_shape(res.shape, v.shape)).contiguous()
+      v = v.cast(res.dtype)._broadcast_to(_broadcast_shape(res.shape, v.shape))
       res.assign(v).realize()
 
   def __delitem__(self, indices) -> None: