FIFO depth optimization

hls4ml/backends/vivado/passes/fifo_depth_optimization.py

@@ -0,0 +1,90 @@
+import json
+
+from pyDigitalWaveTools.vcd.parser import VcdParser
+
+from hls4ml.model.optimizer.optimizer import ConfigurableOptimizerPass, ModelOptimizerPass
+
+
+def populate_values(values, name, data, depth):
+    values.append({'name': name, 'data': [], 'max': 0, 'depth': 0})
+    get_values = lambda x: int(x[1][1:], 2)
+    values[-1]['data'] = [get_values(x) for x in data]
+    values[-1]['max'] = max(values[-1]['data'])
+    values[-1]['depth'] = int(depth[0][1][1:], 2)
+    return values
+
+
+def set_big_fifos(vars_to_profile, profiling_fifo_depth):
+    for k, v in vars_to_profile.items():
+        v.pragma = (v.pragma[0], profiling_fifo_depth)
+
+
+def get_vcd_data(model):
+    model.write()
+    model.build(reset=False, csim=True, synth=True, cosim=True, validation=False, export=False, vsynth=False,
+                fifo_opt=True)
+
+    with open(
+            model.config.get_output_dir() + '/' + model.config.get_project_name() + '_prj' + '/solution1/sim/verilog/fifo_opt.vcd') as vcd_file:
+        vcd = VcdParser()
+        vcd.parse(vcd_file)
+        data = vcd.scope.toJson()
+    return data
+
+
+def generate_max_depth_file(model, maxs):
+    with open(model.config.get_output_dir() + '/max_depth.json', 'w') as f:
+        json.dump(maxs, f, indent=4)
+
+
+def set_fifo_depth(model, maxs):
+    for k, v in model.output_vars.items():
+        filtered_max = [x['max'] for x in maxs if v.name in x['name']]
+        if len(filtered_max) == 0:
+            continue
+        if len(filtered_max) > 1:
+            print('WARNING! Check names of FIFOs')
+        v.pragma = (v.pragma[0], filtered_max[0] + 1)
+
+
+class FifoDepthOptimization(ConfigurableOptimizerPass, ModelOptimizerPass):
+    def __init__(self):
+        self.values = []
+
+    def transform(self, model):
+        # use `large_fifo_depth = 0` to keep the default fifo depth
+        profiling_fifo_depth = getattr(self, 'profiling_fifo_depth', 100_000)
+
+        # check axi-stream or io-stream, if not one the 2 exit
+        if not (model.config.get_config_value('IOType') == 'io_stream'):
+            raise Exception('To use this optimization you have to set `IOType` field to `io_stream` in the HLS config')
+
+        # initialize all the fifos to `profiling_fifo_depth` so that they will be automatically implemented in BRAMs
+        # and so they will be profiled
+        if profiling_fifo_depth:
+            vars_to_profile = {k: v for k, v in model.output_vars.items() if v != model.get_output_variables()[0] and
+                               v != model.get_input_variables()[0]}
+
+            set_big_fifos(vars_to_profile, profiling_fifo_depth)
+
+        data = get_vcd_data(model)
+
+        if len(data['children']) == 0:
+            print("FIFO depth optimization found no FIFOs implemented using BRAMs in the design, no optimization is possible. Consider increasing profiling_fifo_depth.")
+            return False
+
+        n_elem = len(data['children'][0]['children'][0]['children'])
+        for i in range(n_elem):
+            name = data['children'][0]['children'][0]['children'][i]['name']
+            data_p = data['children'][0]['children'][0]['children'][i]['children'][0]['data']
+            depth = data['children'][0]['children'][0]['children'][i]['children'][1]['data']
+            populate_values(self.values, name, data_p, depth)
+
+        maxs = [{'name': i['name'], 'max': i['max'], 'depth': i['depth']} for i in self.values]
+
+        generate_max_depth_file(model, maxs)
+
+        set_fifo_depth(model, maxs)
+
+        print('[hls4ml] - FIFO optimization completed')
+        return False

hls4ml/backends/vivado/vivado_backend.py

@@ -72,11 +72,17 @@ def _register_flows(self):
         ]
         self._writer_flow = register_flow('write', writer_passes, requires=['vivado:ip'], backend=self.name)
 
+        fifo_depth_opt_passes = [
+            'vivado:fifo_depth_optimization'
+        ] + writer_passes # After optimization, a new project will be written
+
+        register_flow('fifo_depth_optimization', fifo_depth_opt_passes, requires=[self._writer_flow], backend=self.name)
+
         all_passes = get_backend_passes(self.name)
 
         extras = [
             # Ideally this should be empty
-            opt_pass for opt_pass in all_passes if opt_pass not in initializers + streaming_passes + quantization_passes + optimization_passes + vivado_types + templates + writer_passes
+            opt_pass for opt_pass in all_passes if opt_pass not in initializers + streaming_passes + quantization_passes + optimization_passes + vivado_types + templates + writer_passes + fifo_depth_opt_passes
         ]
 
         if len(extras) > 0:
@@ -105,16 +111,16 @@ def create_initial_config(self, part='xcku115-flvb2104-2-i', clock_period=5, io_
 
         return config
 
-    def build(self, model, reset=False, csim=True, synth=True, cosim=False, validation=False, export=False, vsynth=False):
+    def build(self, model, reset=False, csim=True, synth=True, cosim=False, validation=False, export=False, vsynth=False, fifo_opt=False):
         if 'linux' in sys.platform:
             found = os.system('command -v vivado_hls > /dev/null')
             if found != 0:
                 raise Exception('Vivado HLS installation not found. Make sure "vivado_hls" is on PATH.')
 
         curr_dir = os.getcwd()
         os.chdir(model.config.get_output_dir())
-        os.system('vivado_hls -f build_prj.tcl "reset={reset} csim={csim} synth={synth} cosim={cosim} validation={validation} export={export} vsynth={vsynth}"'
-            .format(reset=reset, csim=csim, synth=synth, cosim=cosim, validation=validation, export=export, vsynth=vsynth))
+        os.system('vivado_hls -f build_prj.tcl "reset={reset} csim={csim} synth={synth} cosim={cosim} validation={validation} export={export} vsynth={vsynth} fifo_opt={fifo_opt}"'
+            .format(reset=reset, csim=csim, synth=synth, cosim=cosim, validation=validation, export=export, vsynth=vsynth, fifo_opt=fifo_opt))
         os.chdir(curr_dir)
 
         return parse_vivado_report(model.config.get_output_dir())

hls4ml/backends/vivado_accelerator/passes/fifo_depth_optimization.py

@@ -0,0 +1,58 @@
+from hls4ml.backends.vivado.passes.fifo_depth_optimization import set_big_fifos, get_vcd_data, populate_values, \
+    generate_max_depth_file, set_fifo_depth
+from hls4ml.model.optimizer.optimizer import ConfigurableOptimizerPass, ModelOptimizerPass
+
+
+class FifoDepthOptimization(ConfigurableOptimizerPass, ModelOptimizerPass):
+    def __init__(self):
+        self.values = []
+
+    def transform(self, model):
+        # use `large_fifo_depth = 0` to keep the default fifo depth
+        profiling_fifo_depth = getattr(self, 'profiling_fifo_depth', 100_000)
+
+        # check axi-stream or io-stream, if not one the 2 exit
+        if not(model.config.get_config_value('IOType') == 'io_stream' or
+               model.config.get_config_value('AcceleratorConfig')['Interface'] == 'axi_stream' or
+               model.config.get_config_value('AcceleratorConfig')['Interface'] == 'axi_master'):
+            raise Exception('To use this optimization you have to set `IOType` field to `io_stream` in the HLS config '
+                            'or `axi_stream` or `axi_master` in `AcceleratorConfig` interface field')
+
+        # initialize all the fifos to 10000 so that they will be automatically implemented in BRAMs and so they will be
+        # profiled
+
+        if profiling_fifo_depth:
+            set_big_fifos(model.output_vars, profiling_fifo_depth)
+
+        data = get_vcd_data(model)
+
+        for i in range(1, len(data['children'][0]['children'][0]['children'])):
+            # wrapper fifos
+            populate_values(self.values,
+                            data['children'][0]['children'][0]['children'][i]['name'],
+                            data['children'][0]['children'][0]['children'][i]['children'][0]['data'],
+                            data['children'][0]['children'][0]['children'][i]['children'][1]['data'])
+
+        n_elem = len(data['children'][0]['children'][0]['children'][0]['children'])
+        for i in range(n_elem):
+            name   = data['children'][0]['children'][0]['children'][0]['children'][i]['name']
+            data_p = data['children'][0]['children'][0]['children'][0]['children'][i]['children'][0]['data']
+            depth  = data['children'][0]['children'][0]['children'][0]['children'][i]['children'][1]['data']
+            populate_values(self.values, name, data_p, depth)
+
+        maxs = [{'name': i['name'], 'max': i['max'], 'depth': i['depth']} for i in self.values]
+
+        generate_max_depth_file(model, maxs)
+
+        set_fifo_depth(model, maxs)
+
+        inp = model.get_input_variables()[0]
+        out = model.get_output_variables()[0]
+        for x in maxs:
+            if 'in_local' in x['name']:
+                inp.pragma = (inp.pragma[0], x['max'] + 1)
+            elif 'out_local' in x['name']:
+                out.pragma = (out.pragma[0], x['max'] + 1)
+
+        print('[hls4ml] - FIFO optimization completed')
+        return False

hls4ml/backends/vivado_accelerator/vivado_accelerator_backend.py

@@ -9,9 +9,9 @@ def __init__(self):
         super(VivadoBackend, self).__init__(name='VivadoAccelerator')
         self._register_flows()
 
-    def build(self, model, reset=False, csim=True, synth=True, cosim=False, validation=False, export=False, vsynth=False, bitfile=False):
+    def build(self, model, reset=False, csim=True, synth=True, cosim=False, validation=False, export=False, vsynth=False, fifo_opt=False, bitfile=False):
         # run the VivadoBackend build
-        report = super().build(model, reset=reset, csim=csim, synth=synth, cosim=cosim, validation=validation, export=export, vsynth=vsynth)
+        report = super().build(model, reset=reset, csim=csim, synth=synth, cosim=cosim, validation=validation, export=export, vsynth=vsynth, fifo_opt=fifo_opt)
         # Get Config to view Board and Platform
         from hls4ml.backends import VivadoAcceleratorConfig
         vivado_accelerator_config=VivadoAcceleratorConfig(model.config, model.get_input_variables(),model.get_output_variables())
@@ -98,8 +98,20 @@ def create_initial_config(self, board='pynq-z2', part=None, clock_period=5, io_t
 
         return config
 
+    def get_default_flow(self):
+        return self._default_flow
+
+    def get_writer_flow(self):
+        return self._writer_flow
+
     def _register_flows(self):
         vivado_ip = 'vivado:ip'
         writer_passes = ['make_stamp', 'vivadoaccelerator:write_hls']
         self._writer_flow = register_flow('write', writer_passes, requires=[vivado_ip], backend=self.name)
         self._default_flow = vivado_ip
+
+        fifo_depth_opt_passes = [
+            'vivadoaccelerator:fifo_depth_optimization'
+        ] + writer_passes
+
+        register_flow('fifo_depth_optimization', fifo_depth_opt_passes, requires=[self._writer_flow], backend=self.name)

hls4ml/report/vivado_report.py

@@ -31,17 +31,22 @@ def read_vivado_report(hls_dir, full_report=False):
         print('Reports for solution "{}":\n'.format(sln))
         _find_reports(sln_dir + '/' + sln, top_func_name, full_report)
 
-def _parse_build_script(script_path):
+def _parse_build_script(path):
     prj_dir = None
     top_func_name = None
 
-    with open(script_path, 'r') as f:
+    build_path = path + '/build_prj.tcl'
+    project_path = path + '/project.tcl'
+    with open(build_path, 'r') as f:
         for line in f.readlines():
-            if 'open_project' in line:
-                prj_dir = line.split()[-1]
-            elif 'set_top' in line:
+            if 'set_top' in line:
                 top_func_name = line.split()[-1]
 
+    with open(project_path, 'r') as f:
+        for line in f.readlines():
+            if 'set myproject' in line:
+                prj_dir = line.split('"')[-2] + '_prj'
+
     return prj_dir, top_func_name
 
 def _find_solutions(sln_dir):
@@ -109,7 +114,7 @@ def parse_vivado_report(hls_dir):
     top_func_name = None
 
     if os.path.isfile(hls_dir + '/build_prj.tcl'):
-        prj_dir, top_func_name = _parse_build_script(hls_dir + '/build_prj.tcl')
+        prj_dir, top_func_name = _parse_build_script(hls_dir)
 
     if prj_dir is None or top_func_name is None:
         print('Unable to read project data. Exiting.')