XLS backend

hls4ml/backends/__init__.py

@@ -10,6 +10,7 @@
 from hls4ml.backends.catapult.catapult_backend import CatapultBackend  # isort: skip
 
 from hls4ml.backends.vitis.vitis_backend import VitisBackend  # isort: skip
+from hls4ml.backends.xls.xls_backend import XLSBackend
 
 register_backend('Vivado', VivadoBackend)
 register_backend('VivadoAccelerator', VivadoAcceleratorBackend)
@@ -18,3 +19,4 @@
 register_backend('Catapult', CatapultBackend)
 register_backend('SymbolicExpression', SymbolicExpressionBackend)
 register_backend('oneAPI', OneAPIBackend)
+register_backend('XLS', XLSBackend)

hls4ml/backends/backend.py

@@ -1,3 +1,10 @@
+# Typing imports
+from __future__ import annotations # makes all annotations into strings
+from typing import List, Any, TYPE_CHECKING
+if TYPE_CHECKING:
+    pass # Add typing classes here
+
+from numpy.lib._iotools import str2bool
 import inspect
 import os
 from pathlib import Path
@@ -56,7 +63,7 @@ def _get_layer_initializers(self):
     def _get_layer_templates(self):
         return [name for name in get_backend_passes(self.name) if isinstance(get_optimizer(name), Template)]
 
-    def create_initial_config(self, **kwargs):
+    def create_initial_config(self, **kwargs) -> dict[str, Any]:
         """Create the minimal conversion config for the backend.
 
         Subclasses should implement this method to provide the initial configuration for the conversion.
@@ -82,7 +89,7 @@ def get_available_flows(self):
         """
         return get_backend_flows(self.name)
 
-    def get_default_flow(self):
+    def get_default_flow(self) -> str:
         """The name of the default flow of the backend.
 
         Default flow is used as the conversion target if the target flow has not been specified.
@@ -152,7 +159,6 @@ def register_template(self, template_cls):
 
 backend_map = {}
 
-
 def register_backend(name, backend_cls):
     """Create the backend instance and add it to the registry.
 

hls4ml/backends/fpga/fpga_backend.py

@@ -1,3 +1,9 @@
+# Typing imports
+from __future__ import annotations # makes all annotations into strings
+from typing import List, Any, TYPE_CHECKING
+if TYPE_CHECKING:
+    pass # Add typing classes here
+
 import math
 import re
 import subprocess
@@ -187,6 +193,7 @@ def compile(self, model):
 
         return lib_name
 
+
     def write(self, model):
         """Write the generated project to disk.
 
@@ -199,7 +206,7 @@ def write(self, model):
 
         model.apply_flow(self.get_writer_flow())
 
-    def get_writer_flow(self):
+    def get_writer_flow(self) -> str:
         raise NotImplementedError
 
     def get_layer_mult_size(self, layer):

hls4ml/backends/xls/passes/build_attr.py

@@ -0,0 +1,253 @@
+# Typing imports
+from __future__ import annotations # makes all annotations into strings
+from typing import List, Literal, Any, Optional, Callable, TYPE_CHECKING
+from numpy.typing import NDArray
+if TYPE_CHECKING:
+    from hls4ml.model.graph import ModelGraph
+    from hls4ml.model.layers import Layer
+
+
+from hls4ml.model.optimizer import OptimizerPass
+
+from functools import wraps
+import numpy as np
+from fxpmath import Fxp
+
+
+class XLSAttrBuilder:
+    """A helper class that sets XLS specific attributes for the layers of the original ModelGraph.
+    In doing so, we simplify the process of creating new optimization passes 
+    and constructing the writer class. 
+    The new attributes must be accessed with '.get_attr(...)'
+
+    New attributes:
+        write_weights (bool): the layer contains weights that should be explicitly defined in the project file
+        write_dims (bool):    the layer dimensions should be explicitly written in the project file
+        write_func (bool):    the layer has a corresponding function call that should be explicitly written
+                              as part of the NN architecture in the project file
+        func_call (str):      the corresponding layer DSLX function call 
+
+        in_dim_key, out_dim_key (str): the variable name containing the layer dimensions (that goes in and out the layer)
+        in_dim_val, out_dim_val (int): the value of each layer dimension (that goes in and out the layer)
+
+        fxp_weights (np.ndarray): already quantized weight matrix
+        fxp_bias (np.ndarray):    already quantized bias vector
+
+        in_nb, in_en, in_bu (str): parameters used for fixed point computation in DSLX
+                                   the parameters of the input vector 
+                                   number of bits (width), is negative, binary unsigned exponent (frac bits)
+        out_nb, out_en, out_bu (str): parameters used for fixed point computation in DSLX
+                                      the parameters of the output vector 
+                                      number of bits (width), is negative, binary unsigned exponent (frac bits)
+
+    Args:
+        node (Layer): A layer of the model graph
+    """
+
+    def __init__(self, node) -> None:
+        self.node = node
+
+    @staticmethod
+    def attach_to_node(attr_name: Optional[str] = None) :
+        """A decorator-factory to easily chain 'set_attr' commands to the node.
+        It calls the provided function. This eliminates a lot of boiler plate code.
+        All the added attributes can be chained in one call since the wrapped function returns self.
+        """
+        def decorator(fn) -> Callable:
+            name = attr_name or fn.__name__
+            @wraps(fn)
+            def wrapped(self, *args, **kwargs):
+                val = fn(self, *args, **kwargs)
+                self.node.set_attr(name, val)
+                return self
+            return wrapped
+        return decorator
+
+    @attach_to_node()
+    def write_weights(self) -> bool:
+        return self.node.class_name in ['Dense']
+
+    @attach_to_node()
+    def write_dims(self) -> bool:
+        return self.node.class_name in ['Input', 'Dense']
+
+    @attach_to_node()
+    def write_func(self) -> bool:
+        return self.node.class_name in ['Dense', 'Activation', 'Softmax']
+
+
+    @attach_to_node()
+    def in_dim_key(self, v: str) -> str:
+        return v
+
+    @attach_to_node()
+    def in_dim_val(self, v: int) -> int:
+        return v
+
+    @attach_to_node()
+    def out_dim_key(self, v: str) -> str:
+        return v
+
+    @attach_to_node()
+    def out_dim_val(self, v: int) -> int:
+        return v
+
+    @attach_to_node()
+    def fxp_weights(self, weights, out_dim: int, in_dim: int) -> NDArray[NDArray[np.int_]]:
+        #TODO: check which element in the precision array should we take Currently we assume the precision of weights is the first elem.
+        # has weights
+        if len(weights) >= 1:
+            width = int(self.node.get_attr('in_nb').split(':', 1)[1])
+            frac = int(self.node.get_attr('in_bu').split(':', 1)[1])
+
+            mat = np.array(list(list(weights)[0])).reshape(in_dim, out_dim)
+            mat_T = mat.T   # in Keras the weights are transposed
+            fxp_w: NDArray[NDArray[np.int_]] = Fxp(mat_T, signed=True, n_word=width, n_frac=frac).raw()
+            return fxp_w 
+        return np.array([])
+
+    @attach_to_node()
+    def fxp_bias(self, weights) -> NDArray[np.int_]:
+        #TODO: check which element in the precision array should we take Currently we assume the precision of weights is the first elem.
+        # has bias
+        if len(weights) >= 2:
+            width = int(self.node.get_attr('in_nb').split(':', 1)[1])
+            frac = int(self.node.get_attr('in_bu').split(':', 1)[1])
+
+            fxp_b: NDArray[np.int_] = Fxp(list(list(weights)[1]), signed=True, n_word=width, n_frac=frac).raw()
+            return fxp_b
+        return np.array([])
+
+    @attach_to_node()
+    def in_nb(self, prev_layer_precision: dict | None) -> str: # TODO: right now we only care about the first defined type in the list
+        if prev_layer_precision:
+            for _, type_var in prev_layer_precision.items():
+                return f'u32:{type_var.precision.width}'
+        return ''
+
+    @attach_to_node()
+    def in_en(self) -> Literal['u32:1']:
+        return 'u32:1'
+
+    @attach_to_node()
+    def in_bu(self, prev_layer_precision: dict | None) -> str:
+        if prev_layer_precision:
+            for _, type_var in prev_layer_precision.items():
+                return f'u32:{type_var.precision.width - type_var.precision.integer}'
+        return ''
+
+    @attach_to_node()
+    def out_nb(self, layer_precision: dict) -> str:
+        if layer_precision.get('result_t', False):
+            width = layer_precision['result_t'].precision.width
+            return f'u32:{width}'
+        for _, type_var in layer_precision.items():
+            return f'u32:{type_var.precision.width}'
+        return ''
+
+    @attach_to_node()
+    def out_en(self) -> Literal['u32:1']:
+        return 'u32:1'
+
+    @attach_to_node()
+    def out_bu(self, layer_precision) -> str:
+        if layer_precision.get('result_t', False):
+            width = layer_precision['result_t'].precision.width
+            integer = layer_precision['result_t'].precision.integer
+            return f'u32:{width - integer}'
+        for _, type_var in layer_precision.items():
+            return f'u32:{type_var.precision.width - type_var.precision.integer}'
+        return ''
+
+    @attach_to_node()
+    def in_type(self) -> str:
+        return f'sN[{self.node.get_attr("in_nb")}]'
+
+    @attach_to_node()
+    def out_type(self) -> str:
+        return f'sN[{self.node.get_attr("out_nb")}]'
+
+    @attach_to_node()
+    def func_call(self) -> str:
+        func_call_str = ''
+        if self.node.class_name == 'Dense':
+            func_call_str = f'fc::dense<{self.node.get_attr("in_nb")}, {self.node.get_attr("in_en")}, {self.node.get_attr("in_bu")}, {self.node.get_attr("out_nb")}, {self.node.get_attr("out_en")}, {self.node.get_attr("out_bu")}>'
+
+        elif self.node.class_name == 'Activation':
+            func_call_str = f'activations::relu<{self.node.get_attr("out_nb")}>'
+
+        elif self.node.class_name == 'Softmax':
+            implementation = dict(self.node.attributes).get('implementation', 'stable')
+            if implementation == 'stable':
+                table_size = dict(self.node.attributes)['table_size']
+                exp_width = self.node.get_layer_precision()['softmax_exp_table_t'].precision.width
+                exp_frac = exp_width - self.node.get_layer_precision()['softmax_exp_table_t'].precision.integer
+                inv_width = self.node.get_layer_precision()['softmax_inv_table_t'].precision.width
+                inv_frac = inv_width - self.node.get_layer_precision()['softmax_inv_table_t'].precision.integer
+
+                func_call_str = (
+                    f"lookup_tables::softmax_stable<"
+                    f"{self.node.get_attr('in_nb')}, {self.node.get_attr('in_en')}, {self.node.get_attr('in_bu')}, "
+                    f" {self.node.get_attr('out_nb')}, {self.node.get_attr('out_en')}, {self.node.get_attr('out_bu')}, "
+                    f"u32:{exp_width}, u32:1, u32:{exp_frac}, "
+                    f"u32:{inv_width}, u32:1, u32:{inv_frac}, "
+                    f"u32:{table_size}>"
+                )
+            elif implementation == 'latency':
+                table_size = dict(self.node.attributes)['table_size']
+                func_call_str = f'lookup_tables::softmax_latency<{self.node.get_attr("in_nb")}, {self.node.get_attr("in_en")}, {self.node.get_attr("in_bu")}, {self.node.get_attr("out_nb")}, {self.node.get_attr("out_en")}, {self.node.get_attr("out_bu")}, u32:{table_size}>'
+            elif implementation == 'argmax':
+                func_call_str = f'activations::argmax<{self.node.get_attr("in_nb")}, {self.node.get_attr("in_en")}, {self.node.get_attr("in_bu")}, {self.node.get_attr("out_nb")}, {self.node.get_attr("out_en")}, {self.node.get_attr("out_bu")}>'
+        return func_call_str
+
+
+class BuildAttr(OptimizerPass):
+    """Builds the XLS specific attributes for all layers.
+    """
+
+    def match(self, node: Layer) -> bool:
+        if node.class_name == 'Input':
+            return True
+        return False
+
+    def transform(self, model: ModelGraph, node: Layer) -> Literal[False]:        
+        prev_out_dim_key = ''
+        prev_out_dim_val = -1
+        prev_layer_precision = None
+
+        for layer in model.get_layers():
+            curr_out_dim_key: str = list(layer.get_output_variable().get_shape())[0][0]
+            curr_out_dim_val: int = list(layer.get_output_variable().get_shape())[0][1]
+            curr_weights = layer.get_weights()
+            curr_prec: dict = layer.get_layer_precision()
+
+            # uses the builder to add all the attributes
+            b = XLSAttrBuilder(layer)
+            (b
+                .write_dims()
+                .write_weights()
+                .write_func()
+                .in_dim_key(prev_out_dim_key)
+                .in_dim_val(prev_out_dim_val)
+                .out_dim_key(curr_out_dim_key)
+                .out_dim_val(curr_out_dim_val)
+                .in_nb(prev_layer_precision)
+                .in_en()
+                .in_bu(prev_layer_precision)
+                .out_nb(curr_prec)
+                .out_en()
+                .out_bu(curr_prec)
+                .in_type()
+                .out_type()
+                .fxp_weights(curr_weights, out_dim=curr_out_dim_val, in_dim=prev_out_dim_val)
+                .fxp_bias(curr_weights)
+                .func_call()
+
+            )
+
+            prev_out_dim_key = curr_out_dim_key
+            prev_out_dim_val = curr_out_dim_val
+            prev_layer_precision = curr_prec
+
+        return False
+