gpl: Expose PDK-aware GPL parameters through variables.yaml

MODULE.bazel

@@ -65,17 +65,6 @@ single_version_override(
     version = "3.8.2.bcr.7",
 )
 
-# tclZipfs.c's '#include "crypt.h"' picks up glibc's crypt.h instead of
-# the vendored minizip one when glibc headers are explicit -isystem
-# directories (hermetic-llvm zero-sysroot toolchain). Drop when fixed
-# in a tcl_lang BCR release.
-single_version_override(
-    module_name = "tcl_lang",
-    patch_strip = 1,
-    patches = [
-        "//patches/tcl_lang:0001-tclZipfs-include-vendored-minizip-crypt.h-by-path.patch",
-    ],
-)
 
 bazel_dep(name = "openroad", dev_dependency = True)
 local_path_override(

flow/BUILD

@@ -1,5 +1,5 @@
 load("@bazel-orfs//:openroad.bzl", "orfs_pdk")
-load("@rules_python//python:defs.bzl", "py_library", "py_test")
+load("@rules_python//python:defs.bzl", "py_library", "py_test", "py_binary")
 
 # Expose every individual file under platforms/ as a public source-file
 # target, so designs in other packages can refer to e.g.
@@ -24,7 +24,10 @@ exports_files(
 # instead of vendoring its own (drifting) copy at the bazel-orfs repo
 # root. See bazel-orfs `private/rules.bzl`.
 exports_files(
-    ["scripts/synth.tcl"],
+    [
+        "scripts/synth.tcl",
+        "scripts/place_only_and_measure.tcl",
+    ],
     visibility = ["//visibility:public"],
 )
 
@@ -229,3 +232,13 @@ test_suite(
     name = "memories_tests",
     tests = ["memories_" + test for test in MEMORIES_TESTS],
 )
+
+py_binary(
+    name = "tune_gpl_magic",
+    srcs = ["scripts/tune_gpl_magic.py"],
+    deps = [
+        "@orfs-pip//optuna",
+        "@orfs-pip//pyyaml",
+    ],
+    visibility = ["//visibility:public"],
+)

flow/Makefile

@@ -439,6 +439,7 @@ ifeq ($(SYNTH_USE_SYN),1)
 $(eval $(call do-step,1_synth,$(VERILOG_FILES) $(SDC_FILE) $(TECH_LEF) $(SC_LEF) $(ADDITIONAL_LEFS) $(LIB_FILES),synth_syn))
 else
 $(eval $(call do-step,1_synth,$(RESULTS_DIR)/1_2_yosys.v $(RESULTS_DIR)/1_2_yosys.sdc $(TECH_LEF) $(SC_LEF) $(ADDITIONAL_LEFS) $(LIB_FILES),synth_odb))
+do-1_synth: $(RESULTS_DIR)/1_2_yosys.sdc
 endif
 
 $(RESULTS_DIR)/1_synth.sdc: $(RESULTS_DIR)/1_synth.odb

flow/designs/asap7/gcd/config.mk

@@ -16,4 +16,3 @@ export PLACE_DENSITY          = 0.35
 # few last gasp iterations
 export SKIP_LAST_GASP ?= 1
 
-export SYNTH_USE_SYN = 1

flow/designs/design.bzl

@@ -1,7 +1,7 @@
 """BUILD boilerplate for flow/designs/."""
 
-load("@bazel-orfs//:openroad.bzl", "orfs_flow")
-load("@orfs_designs//:designs.bzl", "orfs_design")
+load("@bazel-orfs//:openroad.bzl", "orfs_flow", "orfs_run")
+load("@orfs_designs//:designs.bzl", "orfs_design", "DESIGNS")
 
 # Per filegroup target: extensions included in the filegroup.
 # bazel-orfs's config_mk_parser produces these target names from
@@ -18,7 +18,7 @@ _GROUPS = {
 # cross-package references resolve. Kept tight on purpose: globbing "*"
 # silently exposes LICENSE/.gitignore/etc. as the public API surface.
 # gds/gds.gz are inputs in hierarchical flows via ADDITIONAL_GDS.
-_EXPORTED_EXTS = ["v", "sv", "svh", "tcl", "sdc", "def", "cfg", "lef", "lib", "gds", "gds.gz"]
+_EXPORTED_EXTS = ["v", "sv", "svh", "tcl", "sdc", "def", "cfg", "lef", "lib", "gds", "gds.gz", "memories"]
 
 _EXPORTS_SENTINEL = "_orfs_design_exports_sentinel"
 
@@ -79,6 +79,36 @@ def design(config = "config.mk", user_arguments = [], user_sources = [], local_a
         blender = True,
     )
 
+    pkg = native.package_name()
+    if pkg.startswith("flow/designs/"):
+        design_id = pkg[len("flow/designs/"):]
+        if design_id in DESIGNS:
+            design_args = DESIGNS[design_id]["arguments"]
+            # Find the actual synth target name instantiated by orfs_design
+            synth_name = None
+            for rule_name in native.existing_rules().keys():
+                if rule_name.endswith("_synth"):
+                    synth_name = rule_name
+                    break
+
+            if synth_name:
+                design_name = synth_name[:-6] # Remove "_synth"
+                args_copy = {k: v for k, v in design_args.items()}
+                args_copy["FLOW_VARIANT"] = "tune_gpl"
+                platform = args_copy.get("PLATFORM", design_id.split('/')[0])
+                real_design_name = args_copy.get("DESIGN_NAME", design_name)
+                orfs_run(
+                    name = design_name + "_tune_gpl",
+                    src = ":" + synth_name,
+                    data = [":design_config"],
+                outs = [
+                    "results/{}/{}/tune_gpl/target_function.txt".format(platform, real_design_name),
+                ],
+                arguments = args_copy,
+                script = "//flow:scripts/place_only_and_measure.tcl",
+                variant = "tune_gpl",
+            )
+
 def files(group, extra_srcs = None):
     """Named filegroup over conventional extensions.
 

flow/platforms/asap7/config.json

@@ -0,0 +1,5 @@
+{
+    "GPL_TIMING_SPAN_CLOCK_PERCENT": 0.22968514538823603,
+    "GPL_WIRELENGTH_PENALTY": 0.06456297861599444,
+    "TIGHTEN_CLOCK_PERIOD": 0.018604621846273695
+}

flow/platforms/sky130hd/config.json

@@ -0,0 +1,5 @@
+{
+    "GPL_TIMING_SPAN_CLOCK_PERCENT": 0.188034183753787,
+    "GPL_WIRELENGTH_PENALTY": 0.028702330955746383,
+    "TIGHTEN_CLOCK_PERIOD": 0.04743068706084326
+}

flow/scripts/defaults.py

@@ -9,6 +9,21 @@
 with open(json_path, "r") as file:
     data = json.load(file)
 
+platform_dir = os.environ.get("PLATFORM_DIR")
+if platform_dir:
+    platform_config_path = os.path.join(platform_dir, "config.json")
+    if os.path.exists(platform_config_path):
+        with open(platform_config_path, "r") as file:
+            try:
+                platform_data = json.load(file)
+                for key, value in platform_data.items():
+                    if key in data:
+                        data[key]["default"] = value
+                    else:
+                        data[key] = {"default": value}
+            except json.JSONDecodeError:
+                pass
+
 for key, value in data.items():
     if value.get("default", None) is None:
         continue

flow/scripts/global_place.tcl

@@ -28,6 +28,14 @@ append_env_var global_placement_args GPL_ROUTABILITY_DRIVEN -routability_driven
 
 append_env_var global_placement_args GPL_RANDOM_SEED -random_seed 1
 
+if { [info exists ::env(GPL_WIRELENGTH_PENALTY)] } {
+  lappend global_placement_args -init_wirelength_coef $::env(GPL_WIRELENGTH_PENALTY)
+}
+
+if { [info exists ::env(GPL_TIMING_SPAN_CLOCK_PERCENT)] } {
+  lappend global_placement_args -virtual_cts_max_skew_fraction $::env(GPL_TIMING_SPAN_CLOCK_PERCENT)
+}
+
 # Parameters for timing driven mode in global placement
 if { $::env(GPL_TIMING_DRIVEN) } {
   lappend global_placement_args {-timing_driven}

flow/scripts/place_only_and_measure.tcl

@@ -0,0 +1,42 @@
+# Runs OpenROAD flow up to placement and evaluates minimum achievable clock period.
+
+set ::env(KEEP_VARS) 1
+set ::env(WRITE_ODB_AND_SDC_EACH_STAGE) 0
+
+if { [info exists ::env(ODB_FILE)] } {
+  set odb_path $::env(ODB_FILE)
+  set sdc_path [file rootname $odb_path].sdc
+  file copy -force $odb_path $::env(RESULTS_DIR)/1_synth.odb
+  file copy -force $sdc_path $::env(RESULTS_DIR)/1_synth.sdc
+}
+
+# The synth_odb stage already canonicalized constraints into 1_synth.sdc.
+# Unset SDC_FILE so floorplan.tcl doesn't try to read the original file path
+# which might fail inside the bazel sandbox.
+unset -nocomplain ::env(SDC_FILE)
+
+set ::flow_expected [glob -nocomplain -directory $::env(RESULTS_DIR) *.odb *.sdc]
+
+proc flow_source { script } {
+  uplevel #0 [list source $::env(SCRIPTS_DIR)/$script]
+  foreach f [glob -nocomplain -directory $::env(RESULTS_DIR) *.odb *.sdc] {
+    if { [lsearch -exact $::flow_expected $f] == -1 } {
+      error "$script wrote $f: with WRITE_ODB_AND_SDC_EACH_STAGE=0 stage scripts must not write .odb/.sdc files"
+    }
+  }
+}
+
+# Run the flow up to place
+
+flow_source floorplan.tcl
+flow_source macro_place.tcl
+flow_source tapcell.tcl
+flow_source pdn.tcl
+flow_source global_place_skip_io.tcl
+flow_source io_placement.tcl
+flow_source global_place.tcl
+flow_source resize.tcl
+flow_source detail_place.tcl
+
+# Evaluate target function (measures clock / WNS)
+flow_source target-function.tcl

flow/scripts/target-function.tcl

@@ -0,0 +1,18 @@
+# Evaluate placement by tightening clocks and measuring WNS
+
+if { [info exists ::env(TIGHTEN_CLOCK_PERIOD)] } {
+  foreach clk [all_clocks] {
+    set period [get_property $clk period]
+    set uncertainty [expr {$period * $::env(TIGHTEN_CLOCK_PERIOD)}]
+    set_clock_uncertainty -setup $uncertainty $clk
+    puts "TIGHTEN_CLOCK_PERIOD: Set setup uncertainty for clock [get_property $clk name] to $uncertainty"
+  }
+}
+
+estimate_parasitics -placement
+set wns [sta::time_sta_ui [sta::worst_slack_cmd "max"]]
+puts "Target Function WNS: $wns"
+
+set f [open [file join $::env(RESULTS_DIR) "target_function.txt"] w]
+puts $f $wns
+close $f