pretty kernel in cstyle (#1746)

* pretty kernel in cstyle

* fix mem estimate

* that made it slower

* Revert "that made it slower"

This reverts commit faa4cd0187.

tinygrad/codegen/kernel.py

@@ -2,7 +2,7 @@ from typing import NamedTuple, Optional, List, Tuple, cast, Dict
 import itertools
 from tinygrad.ops import LazyOp, MovementOps, FlopCounter, get_lazyop_info, ReduceOps
 from tinygrad.lazy import LazyBuffer
-from tinygrad.helpers import dedup, dtypes, colored, prod, ImageDType, DType
+from tinygrad.helpers import dedup, dtypes, colored, ImageDType, DType
 from tinygrad.runtime.lib import buf_is_kernel_arg
 from tinygrad.shape.shapetracker import ShapeTracker, strides_for_shape
 
@@ -42,7 +42,7 @@ class Kernel:
 
     # fetch lazyop info
     self.info: FlopCounter = get_lazyop_info(cast(LazyOp, self.ast))
-    self.mem_estimate: int = sum(x.dtype.itemsize*(x.realized.size if x.realized is not None else prod(x.shape)) for x in self.bufs if x is not None)
+    self.mem_estimate: int = sum(x.dtype.itemsize*x.size for x in self.arg_bufs.keys())
 
     # there's only allowed to be one reduceop
     reduceops = [x for x in self.ast.get_lazyops() if x.op in ReduceOps]

tinygrad/renderer/cstyle.py

@@ -117,6 +117,11 @@ def uops_to_cstyle(lang:CStyleLanguage, function_name:str, uops:List[UOp])  -> T
     return f"{prefix}{c[prefix]-1}"
   r: Dict[UOp, str] = {}
 
+  child_count: DefaultDict[UOp, int] = defaultdict(int)
+  for ru in uops:
+    for v in ru.vin:
+      child_count[v] += 1
+
   for u in uops:
     uop,dtype,vin,args,_ = u
     if uop == UOps.LOOP:
@@ -166,8 +171,11 @@ def uops_to_cstyle(lang:CStyleLanguage, function_name:str, uops:List[UOp])  -> T
         raise NotImplementedError(f"WMMA not implemented for {args}")
     elif uop == UOps.ALU:
       assert dtype is not None
-      r[u] = ssa('alu')
-      kk(f"{lang.generic_var_prefix if lang.generic_var_prefix else dtype.name} {r[u]} = {lang.code_for_op[args](*[r[x] for x in vin])};")
+      val = lang.code_for_op[args](*[r[x] for x in vin])
+      if child_count[u] == 1: r[u] = val
+      else:
+        r[u] = ssa('alu')
+        kk(f"{lang.generic_var_prefix if lang.generic_var_prefix else dtype.name} {r[u]} = {val};")
     elif uop == UOps.DEFINE_ACC:
       assert dtype is not None
       r[u] = ssa('acc')