move VALID creation after merging the views (tinygrad#8757)

* do valid creation later

* work for view_left

* only view(const) makes valids in view_left

* cleaner bind diff

Author: Qazalin

Diff for: tinygrad/engine/schedule.py

@@ -199,6 +199,8 @@ def _append_buf(ctx:ScheduleItemContext, x:UOp) -> UOp:
   (UPat(Ops.PRELOAD, name="root"), lambda root:root.replace(op=Ops.LOAD)),
   # once images are loaded they become the base dtype
   (UPat(set(Ops)-{Ops.DEFINE_GLOBAL}, name="x"), lambda x: x.replace(dtype=x.dtype.base) if isinstance(x.dtype, ImageDType) else None),
+  # CONST(VIEW) becomes VALID too, TODO: doesn't have to
+  (UPat(Ops.CONST, name="x", src=(UPat(Ops.VIEW, name="st"),)), lambda x,st: UOp.const(x.dtype, x.const_arg).valid(st.st)),
 ])
 
 # LOAD(BUFFER) -> the STORE value if it's we're doing the STORE in the same kernel
@@ -438,11 +440,11 @@ def create_subbuffer(base:UOp, b:UOp, root:UOp, x:UOp):
   (UPatScheduled((Ops.BITCAST, Ops.CONTIGUOUS), name="root", src=(UPat.var("x"),)), create_subbuffer),
 ])
 
-# **** rewrite VIEW into LOAD/STORE/VALID or fuse the underlying UOp
+# **** rewrite VIEW into LOAD/STORE or fuse the underlying UOp
 
 def unbind_variable(ctx:ScheduleContext, bind:UOp, var:UOp, val:UOp):
-  assert isinstance(val.src[1].const_arg, int), f"expected BIND value to be int {val}"
-  ctx.var_vals[ret:=var.replace(src=())] = val.src[1].const_arg
+  assert isinstance(val.const_arg, int), f"expected BIND value to be int {val}"
+  ctx.var_vals[ret:=var.replace(src=())] = val.const_arg
   return ret.valid(unwrap(bind.st))
 
 def load_realized(ctx:ScheduleContext, b:UOp, st:UOp):
@@ -456,8 +458,6 @@ def store_or_fuse(ctx:ScheduleContext, b:UOp, x:UOp, st:UOp):
   return UOp(Ops.LOAD, x.dtype, (b, unwrap(st.st).to_uop()))
 
 break_sched = PatternMatcher([
-  # CONST is always fused and generated
-  (UPat(Ops.CONST, name="x", src=(UPat(Ops.VIEW, name="st"),)), lambda x,st: UOp.const(x.dtype, x.const_arg).valid(st.st)),
   (UPat(Ops.BIND, name="bind", src=(UPat.var("var"), UPat.var("val"))), unbind_variable),
   # VIEW of BUFFER either becomes a LOAD/STORE or we fuse it
   (UPat(Ops.VIEW, name="st", src=(UPat(Ops.BUFFER, name="b"),)), load_realized),
@@ -481,9 +481,6 @@ def append_uop(ctx:ScheduleContext, view:UOp, buf_uop:UOp) -> None:
   # some masked views can collapse to 0, VIEW(x) -> CONST(VIEW)
   (UPat(Ops.VIEW, name="view"),
    lambda view: view.const_like(0) if (vm:=view.st.views[-1].mask) is not None and any((x[1]-x[0]) == 0 for x in vm) else None),
-  # merge unmasked const views
-  (UPat(Ops.VIEW, name="view", src=(UPat(Ops.CONST, name="const", src=(UPat(Ops.VIEW, name="st"),) ),)),
-   lambda st,const,view: const.replace(src=(st.replace(arg=st.st+view.st),)) if all(v.mask is None for v in (st.st+view.st).views) else None),
 ])
 
 @track_rewrites(named=True)

Diff for: tinygrad/ops.py

@@ -1322,10 +1322,15 @@ def sint_to_uop(x:sint, dtype:DType=dtypes.int) -> UOp: return UOp.const(dtype,
   # VIEW(VIEW) merges to a single VIEW
   (UPat(Ops.VIEW, name="vm1", src=(UPat(Ops.VIEW, name="vm2"),)), lambda vm1,vm2: vm2.replace(arg=vm2.st+vm1.st)),
   (UPat(Ops.VIEW, name="vm", src=(UPat.var("x"),)), lambda vm,x: x if vm.st.contiguous and x.st is not None and x.shape == vm.shape else None),
+  # merge unmasked const views
+  (UPat(Ops.VIEW, name="view", src=(UPat(Ops.CONST, name="const", src=(UPat(Ops.VIEW, name="st"),) ),)),
+   lambda st,const,view: const.replace(src=(st.replace(arg=st.st+view.st),)) if all(v.mask is None for v in (st.st+view.st).views) else None),
 ])
 
 # push VIEW to parents
 view_left = merge_views+PatternMatcher([
+  # VIEW(CONST) becomes VALID
+  (UPat(Ops.VIEW, name="vm", src=(UPat.cvar("x"),)), lambda vm,x: UOp.const(x.dtype, x.const_arg).valid(vm.st)),
   # VIEW before elementwise/buffer ops
   (UPat(Ops.VIEW, name="vm", src=(UPat({*GroupOp.ALU, Ops.CAST, Ops.BITCAST, Ops.ASSIGN}, name="e"),)),
    lambda e,vm: e.replace(src=tuple(s if s.st is None else s.view(vm.st) if s is s.base else s.base.view(s.st+vm.st) for s in e.src))),