Hardcode weights loading (ensures weights loading works from any dir)

Author: vloncar

hls4ml/model/graph.py

@@ -805,32 +805,24 @@ def predict(self, x):
         n_inputs = len(self.get_input_variables())
         n_outputs = len(self.get_output_variables())
 
-        curr_dir = os.getcwd()
-        os.chdir(self.config.get_output_dir() + '/firmware')
-
         output = []
         if n_samples == 1 and n_inputs == 1:
             x = [x]
 
-        try:
-            for i in range(n_samples):
-                predictions = [np.zeros(yj.size(), dtype=ctype) for yj in self.get_output_variables()]
-                if n_inputs == 1:
-                    inp = [np.asarray(x[i])]
-                else:
-                    inp = [np.asarray(xj[i]) for xj in x]
-                argtuple = inp
-                argtuple += predictions
-                argtuple = tuple(argtuple)
-                top_function(*argtuple)
-                output.append(predictions)
-
-            # Convert to list of numpy arrays (one for each output)
-            output = [
-                np.asarray([output[i_sample][i_output] for i_sample in range(n_samples)]) for i_output in range(n_outputs)
-            ]
-        finally:
-            os.chdir(curr_dir)
+        for i in range(n_samples):
+            predictions = [np.zeros(yj.size(), dtype=ctype) for yj in self.get_output_variables()]
+            if n_inputs == 1:
+                inp = [np.asarray(x[i])]
+            else:
+                inp = [np.asarray(xj[i]) for xj in x]
+            argtuple = inp
+            argtuple += predictions
+            argtuple = tuple(argtuple)
+            top_function(*argtuple)
+            output.append(predictions)
+
+        # Convert to list of numpy arrays (one for each output)
+        output = [np.asarray([output[i_sample][i_output] for i_sample in range(n_samples)]) for i_output in range(n_outputs)]
 
         if n_samples == 1 and n_outputs == 1:
             return output[0][0]

hls4ml/templates/catapult/myproject_bridge.cpp

@@ -6,7 +6,7 @@
 #include <algorithm>
 #include <map>
 
-static std::string s_weights_dir = "weights";
+// hls-fpga-machine-learning insert weights dir
 
 const char *get_weights_dir() { return s_weights_dir.c_str(); }
 

hls4ml/writer/catapult_writer.py

@@ -676,6 +676,9 @@ def write_bridge(self, model):
                 newline = line.replace('MYPROJECT', format(model.config.get_project_name().upper()))
             elif 'myproject' in line:
                 newline = line.replace('myproject', format(model.config.get_project_name()))
+            elif '// hls-fpga-machine-learning insert weights dir' in line:
+                weights_dir = (Path(fout.name).parent / 'firmware/weights').resolve()
+                newline = f'static std::string s_weights_dir = "{weights_dir}";\n'
             elif '// hls-fpga-machine-learning insert bram' in line:
                 newline = line
                 for bram in model_brams:

hls4ml/writer/vivado_writer.py

@@ -725,10 +725,13 @@ def write_build_script(self, model):
         # build_lib.sh
         build_lib_src = (filedir / '../templates/vivado/build_lib.sh').resolve()
         build_lib_dst = Path(f'{model.config.get_output_dir()}/build_lib.sh').resolve()
+        weights_dir = (build_lib_dst.parent / 'firmware/weights').resolve()
         with open(build_lib_src) as src, open(build_lib_dst, 'w') as dst:
             for line in src.readlines():
                 line = line.replace('myproject', model.config.get_project_name())
                 line = line.replace('mystamp', model.config.get_config_value('Stamp'))
+                if line.startswith('WEIGHTS_DIR='):
+                    line = f'WEIGHTS_DIR=\\""{weights_dir}\\""\n'
 
                 dst.write(line)
         build_lib_dst.chmod(build_lib_dst.stat().st_mode | stat.S_IEXEC)