[Util] introduce out_of_context_synth

src/finn/util/vivado.py

+# Copyright (c) 2020, Xilinx
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright notice,
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+#
+# * Neither the name of FINN nor the names of its
+#   contributors may be used to endorse or promote products derived from
+#   this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import os
+import subprocess
+
+
+def which(program):
+    "Python equivalent of the shell cmd 'which'."
+
+    # source:
+    # https://stackoverflow.com/questions/377017/test-if-executable-exists-in-python
+    def is_exe(fpath):
+        return os.path.isfile(fpath) and os.access(fpath, os.X_OK)
+
+    fpath, fname = os.path.split(program)
+    if fpath:
+        if is_exe(program):
+            return program
+    else:
+        for path in os.environ["PATH"].split(os.pathsep):
+            exe_file = os.path.join(path, program)
+            if is_exe(exe_file):
+                return exe_file
+
+    return None
+
+
+def out_of_context_synth(
+    verilog_dir,
+    top_name,
+    fpga_part="xczu3eg-sbva484-1-e",
+    clk_name="ap_clk_0",
+    clk_period_ns=5.0,
+):
+    "Run out-of-context Vivado synthesis, return resources and slack."
+
+    # ensure that the OH_MY_XILINX envvar is set
+    if "OHMYXILINX" not in os.environ:
+        raise Exception("The environment variable OHMYXILINX is not defined.")
+    # ensure that vivado is in PATH: source $VIVADO_PATH/settings64.sh
+    if which("vivado") is None:
+        raise Exception("vivado is not in PATH, ensure settings64.sh is sourced.")
+    omx_path = os.environ["OHMYXILINX"]
+    script = "vivadocompile.sh"
+    # vivadocompile.sh <top-level-entity> <clock-name (optional)> <fpga-part (optional)>
+    call_omx = "zsh %s/%s %s %s %s %f" % (
+        omx_path,
+        script,
+        top_name,
+        clk_name,
+        fpga_part,
+        float(clk_period_ns),
+    )
+    call_omx = call_omx.split()
+    proc = subprocess.Popen(
+        call_omx, cwd=verilog_dir, stdout=subprocess.PIPE, env=os.environ
+    )
+    proc.communicate()
+
+    vivado_proj_folder = "%s/results_%s" % (verilog_dir, top_name)
+    res_counts_path = vivado_proj_folder + "/res.txt"
+
+    with open(res_counts_path, "r") as myfile:
+        res_data = myfile.read().split("\n")
+    ret = {}
+    ret["vivado_proj_folder"] = vivado_proj_folder
+    for res_line in res_data:
+        res_fields = res_line.split("=")
+        print(res_fields)
+        try:
+            ret[res_fields[0]] = float(res_fields[1])
+        except ValueError:
+            ret[res_fields[0]] = 0
+        except IndexError:
+            ret[res_fields[0]] = 0
+    if ret["WNS"] == 0:
+        ret["fmax_mhz"] = 0
+    else:
+        ret["fmax_mhz"] = 1000.0 / (clk_period_ns - ret["WNS"])
+    return ret