fix global pooling bw inference

Author: calad0i

hls4ml/model/optimizer/passes/bit_exact.py

@@ -407,10 +407,7 @@ def _(layer: Conv1D | Conv2D):
 @_produce_kif.register(GlobalPooling1D)
 @_produce_kif.register(GlobalPooling2D)
 def _(layer: Pooling1D | Pooling2D | GlobalPooling1D | GlobalPooling2D):
-    if isinstance(layer, (Pooling1D, GlobalPooling1D)):
-        px_shape = (layer.attributes['pool_width'],)
-    else:
-        px_shape = (layer.attributes['pool_height'], layer.attributes['pool_width'])
+    px_shape = _get_px_shape(layer)
     ch_out = ch_in = layer.attributes['n_filt']
 
     im2col_shape = *px_shape, ch_in, ch_out  # conv kernel shape
@@ -432,6 +429,8 @@ def _(layer: Pooling1D | Pooling2D | GlobalPooling1D | GlobalPooling2D):
             raise ValueError('Average pooling with non-power-of-2 pool size cannot be bit-exact')
         f_out += int(f_add)
 
+    if isinstance(layer, (GlobalPooling1D, GlobalPooling2D)):
+        k_out, i_out, f_out = k_out[0], i_out[0], f_out[0]
     return k_out, i_out, f_out
 
 
@@ -665,6 +664,22 @@ def _(node: UnaryLUT):
     default_register_precision(node)
 
 
+def _get_px_shape(node: Layer):
+    if isinstance(node, Pooling1D):
+        px_shape = (node.attributes['pool_width'],)
+    elif isinstance(node, GlobalPooling1D):
+        inp_shape = get_input_shapes(node)[0]
+        px_shape = (inp_shape[0],)
+    elif isinstance(node, Pooling2D):
+        px_shape = (node.attributes['pool_height'], node.attributes['pool_width'])
+    elif isinstance(node, GlobalPooling2D):
+        inp_shape = get_input_shapes(node)[0]
+        px_shape = (inp_shape[0], inp_shape[1])
+    else:
+        raise ValueError(f'Layer {node.class_name} is not supported for pooling precision derivation')
+    return px_shape
+
+
 @register_precision.register(Pooling1D)
 @register_precision.register(Pooling2D)
 @register_precision.register(GlobalPooling1D)
@@ -674,10 +689,7 @@ def _(node: Pooling1D | Pooling2D | GlobalPooling1D | GlobalPooling2D):
     pool_op = node.attributes['pool_op']
     if pool_op != 'Average':
         return
-    if isinstance(node, (Pooling1D, GlobalPooling1D)):
-        px_shape = (node.attributes['pool_width'],)
-    else:
-        px_shape = (node.attributes['pool_height'], node.attributes['pool_width'])
+    px_shape = _get_px_shape(node)
     i_add = int(log2(prod(px_shape)))
     node.attributes['accum_t'].precision.width += i_add
     node.attributes['accum_t'].precision.integer += i_add