start renderer casted const migration [pr] (#17582)

before rendering, rewrite strong typed const to casted weak const and have renderer adopt the new UOp. starting with PYTHON

test/backend/test_linearizer.py

@@ -252,7 +252,7 @@ class TestLinearizer(unittest.TestCase):
     for u in uops:
       if u.op is Ops.STORE and u.src[0].addrspace is AddrSpace.REG:
         if uops.index(u) < begin_range:
-          assert u.src[1].op is Ops.CONST
+          assert u.src[1].op not in GroupOp.ALU
         else:
           assert u.src[1].op in GroupOp.ALU
           assert begin_range < uops.index(u) < end_range
@@ -261,6 +261,7 @@ class TestLinearizer(unittest.TestCase):
         assert end_range < uops.index(u)
 
   @unittest.skipUnless(Device[Device.DEFAULT].renderer.has_local, "test requires locals")
+  @unittest.skipIf(Device[Device.DEFAULT].renderer.casted_consts, "reads a literal, which is casted here. TODO: flip this")
   def test_default_global_reversed(self):
     # shrink so that the dims do not collapse
     t = Tensor.ones(5, 6, 7).contiguous().realize().shrink(((0, 4), (0, 5), (0, 6)))

tinygrad/codegen/__init__.py

@@ -5,7 +5,7 @@ from tinygrad.helpers import ALLOW_TF32, DEFAULT_FLOAT, DEFAULT_INT, TracingKey,
 from tinygrad.uop.ops import PatternMatcher, graph_rewrite, UOp, Ops, UPat, rewrite_group, KernelInfo, ProgramInfo, GroupOp, AxisType
 from tinygrad.uop.weak import pm_lower_index_dtype, pm_commit_weak, pm_cast_weak
 from tinygrad.uop.render import pyrender
-from tinygrad.uop.spec import type_verify, spec_tensor, spec_program
+from tinygrad.uop.spec import type_verify, spec_tensor, spec_program, spec_program_casted_consts
 from tinygrad.renderer import Renderer, Estimates
 from tinygrad.renderer.isa import ISARenderer, IselContext, PreRegAllocContext
 from tinygrad.dtype import dtypes, AddrSpace
@@ -281,6 +281,10 @@ pm_implicit_barriers = PatternMatcher([
   (UPat(Ops.END, name="end"), add_war_barrier),
 ])
 
+pm_casted_consts = PatternMatcher([
+  (UPat(Ops.CONST, dtypes.all, name="c"), lambda c: UOp(Ops.CAST, c.dtype, src=(UOp.const(c.val),), arg=c.dtype)),
+])
+
 def full_rewrite_to_sink(ast:UOp, ren:Renderer, optimize:bool=True) -> UOp:
   if VIZ: graph_rewrite(ast, PatternMatcher([]), name="View Base AST")
   if DEBUG >= 5: print(pyrender(ast))
@@ -383,8 +387,11 @@ def full_rewrite_to_sink(ast:UOp, ren:Renderer, optimize:bool=True) -> UOp:
   num_params = len([x for x in sink.toposort() if x.op is Ops.PARAM and x.arg.slot != -1])
   sink = graph_rewrite(sink, pm_number_params, ctx=[num_params], name="number params with -1", walk=True)
 
+  # TODO: delete once migration are done
+  if ren.casted_consts: sink = graph_rewrite(sink, pm_casted_consts, name="casted consts", walk=True)
+
   if VIZ: graph_rewrite(sink, PatternMatcher([]), name="View Output AST")
-  if SPEC: type_verify(sink, spec_program)
+  if SPEC: type_verify(sink, spec_program_casted_consts if ren.casted_consts else spec_program)
 
   # return the rewritten sink
   return sink

tinygrad/renderer/__init__.py

@@ -72,6 +72,8 @@ class Renderer:
   tensor_cores: list[TensorCore] = []
   extra_matcher: PatternMatcher|None = None
   code_for_op: dict[Ops, Callable] = {}
+  # migration: this renderer consumes every literal as a casted const CAST(dt, CONST(value))
+  casted_consts: bool = False
 
   compiler: Compiler = Compiler()
 

tinygrad/runtime/ops_python.py

@@ -214,6 +214,7 @@ class PythonCompiler(Compiler):
 class PythonRenderer(Renderer):
   code_for_op = python_alu
   compiler = PythonCompiler()
+  casted_consts: bool = True
 
   def __init__(self, target:Target):
     assert (emu:=getenv("EMULATE", "")) == "", ("EMULATE is deprecated, use DEV=PYTHON::" +

tinygrad/uop/render.py

@@ -81,7 +81,7 @@ sugar = {Ops.SINK, Ops.END, Ops.STORE, Ops.LOAD, Ops.SQRT, Ops.INDEX, Ops.REDUCE
          Ops.RECIPROCAL, Ops.EXP2, Ops.LOG2, Ops.SIN, Ops.CONTIGUOUS, Ops.BARRIER, Ops.DETACH}
 pm_pyrender_extra = PatternMatcher([
   (UPat(Ops.CONST, src=(), name="x"), lambda x: f"UOp.const({x.val}, {x.dtype})"),
-  (UPat((Ops.CAST, Ops.BITCAST), name="x"), lambda ctx,x: f"{ctx[x.src[0]]}.{x.op.name.lower()}({x.dtype})"),
+  (UPat((Ops.CAST, Ops.BITCAST), name="x"), lambda ctx,x: f"{ctx[x.src[0]]}.{x.op.name.lower()}({x.dtype})" if x.dtype != x.src[0].dtype else None),
   (UPat(Ops.SPECIAL, src=(UPat(Ops.CONST),), name="x"), lambda x: f"UOp.special({x.src[0].val}, {repr(x.arg)}, dtype={x.dtype})"),
   (UPat(Ops.BUFFER, src=(UPat(),), name="x"), lambda x:
     f"UOp.new_buffer({repr(x.arg.device)}, {x.max_numel()}, {x.dtype}, {x.arg.slot})"

tinygrad/uop/spec.py

@@ -223,6 +223,12 @@ spec_program = PatternMatcher([
   (UPat(Ops.SPECIAL, src=(UPat.var("x", dtypes.int32),), name="s"), lambda s,x: matches_dtype(x, s.dtype) and isinstance(s.arg, str)),
 ])+spec_shared
 
+# migration: on a casted_consts renderer every literal is CAST(dt, CONST(value)) with a weak inner CONST
+spec_program_casted_consts = PatternMatcher([
+  (UPat(Ops.CONST, dtype=dtypes.weaks, name="x"), lambda x: x.dtype is dtypes.from_py(x.val)),
+  (UPat(Ops.SHRINK, src=(UPat((Ops.PARAM, Ops.BUFFER, Ops.AFTER)), UPat(), UPat(Ops.CAST, src=(UPat(Ops.CONST),)))), lambda: True),
+])+spec_program
+
 spec_hcq = PatternMatcher([
   (UPat(Ops.GETADDR, dtypes.uint64, src=(UPat((Ops.BUFFER, Ops.PARAM)).or_after(),), name="x"), lambda x: is_device(x.arg)),
   (UPat(Ops.PROGRAM, dtypes.void, src=(UPat((Ops.BUFFER, Ops.PARAM)).or_after(),)), lambda: True),

tinygrad/uop/validate.py

@@ -52,6 +52,8 @@ z3_renderer = PatternMatcher([
     create_bounded(f"cast{len(ctx[1])}", x.dtype.min, x.dtype.max, ctx[0])),
   # A comparison between floats introduces a new bool variable
   (UPat(GroupOp.Comparison, src=UPat(dtype=dtypes.floats)), lambda ctx: (z3.Bool(f"float_cmp{len(ctx[1])}", ctx=ctx[0]), None)),
+  # a same-dtype cast states a width, which z3 does not model: identity. must precede the rules below (bool->bool)
+  (UPat(Ops.CAST, name="x"), lambda x,ctx: (ctx[1][x.src[0]], None) if x.dtype == x.src[0].dtype else None),
   # casts from bool/int to int/bool
   (UPat(Ops.CAST, dtypes.ints+(dtypes.weakint,),src=(UPat.var("x", dtypes.bool),)), lambda x,ctx: (z3.If(ctx[1][x], 1, 0), None)),
   (UPat(Ops.CAST, dtypes.ints+(dtypes.weakint,), src=(UPat.var("x", dtypes.ints+(dtypes.weakint,)),)), lambda x,ctx: (ctx[1][x], None)),