From d3500af71b76dee2ad3224576ea54a0348939f2a Mon Sep 17 00:00:00 2001
From: George Hotz <72895+geohot@users.noreply.github.com>
Date: Fri, 25 Oct 2024 13:58:48 +0700
Subject: [PATCH] move consts last in uop toposort (#7290)

* move consts last in uop toposort

* consts first in toposort
---
 tinygrad/codegen/linearize.py | 5 ++++-
 tinygrad/ops.py               | 8 ++++----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/tinygrad/codegen/linearize.py b/tinygrad/codegen/linearize.py
index 1f7d3fa32a..b7c4d26ea5 100644
--- a/tinygrad/codegen/linearize.py
+++ b/tinygrad/codegen/linearize.py
@@ -41,8 +41,11 @@ def linearize_uop(sink:UOp, skip_check:bool=not __debug__) -> List[UOp]:
       priority += u.arg[0]
       for p in range_phi[u]:
         priority += 10000*len([r for r in range_srcs[p] if not any(i in range_phi[u] for i in range_phi[r])])
-    # prefer uops that are loop children
+    elif u.op is UOps.CONST:
+      # place consts first here, they don't do anything and it can cause issues with DEFINE_ACC
+      priority -= 100000000000
     else:
+      # prefer uops that are loop children
       priority -= sum([(l.arg[0]+1) + 1000*l.arg[1] for l,ss in scope_children.items() if l.op is UOps.RANGE and u in ss])
     if u.op is UOps.IF and len(u.src) == 1: priority += 10000000 # if penalty
     return priority
diff --git a/tinygrad/ops.py b/tinygrad/ops.py
index 61476c98d4..3d8d680ac2 100644
--- a/tinygrad/ops.py
+++ b/tinygrad/ops.py
@@ -101,10 +101,6 @@ def identity_element(op:BinaryOps, dt:DType): return dtypes.as_const({BinaryOps.
 
 # the order of these UOps controls the order of the toposort
 class UOps(FastEnum):
-  # consts!
-  VCONST = auto()
-  CONST = auto()
-
   # uops that aren't rendered
   SINK = auto()
   CONTIGUOUS = auto()
@@ -156,6 +152,10 @@ class UOps(FastEnum):
   ENDRANGE = auto()
   ENDIF = auto()
 
+  # consts last!
+  VCONST = auto()
+  CONST = auto()
+
 BUFFER_UOPS = {UOps.LOAD, UOps.PRELOAD, UOps.STORE, UOps.VALID}
 COMMUTATIVE = {BinaryOps.ADD, BinaryOps.MUL, BinaryOps.MAX, BinaryOps.CMPNE, BinaryOps.XOR, BinaryOps.AND, BinaryOps.OR}
 END_FOR_UOP = {UOps.IF:(UOps.STORE, UOps.ENDIF), UOps.RANGE:(UOps.ASSIGN, UOps.ENDRANGE)}