Merge pull request #7904 from gadfort/pdn-check-setup

pdn: add error checking to connect rules to prevent rules with no actual target

Author: maliberty

src/pdn/README.md

@@ -21,6 +21,7 @@ Build a power grid in accordance with the information specified.
 
 ```tcl
 pdngen
+    [-check_only]
     [-dont_add_pins]
     [-failed_via_report file]
     [-report_only]
@@ -36,6 +37,7 @@ pdngen
 | `[-dont_add_pins]` | Prevent the creation of block pins. |
 | `[-failed_via_report]` | Generate a report file which can be viewed in the DRC viewer for all the failed vias (ie. those that did not get built or were removed). |
 | `[-report_only]` | Print the current specifications. |
+| `[-check_only]` | Check the current setup for errors. |
 | `[-reset]` | Reset the grid and domain specifications. |
 | `[-ripup]` | Ripup the existing power grid, as specified by the voltage domains. |
 | `[-skip_trim]` | Skip the metal trim step, which attempts to remove metal stubs. |

src/pdn/include/pdn/PdnGen.hh

@@ -71,6 +71,10 @@ class PdnGen
                              odb::dbMTerm* switched_power,
                              odb::dbMTerm* alwayson_power,
                              odb::dbMTerm* ground);
+  const std::vector<std::unique_ptr<PowerCell>>& getSwitchedPowerCells() const
+  {
+    return switched_power_cells_;
+  }
 
   // Domains
   std::vector<VoltageDomain*> getDomains() const;

src/pdn/src/grid.cpp

@@ -647,6 +647,101 @@ void Grid::checkSetup() const
       }
     }
   }
+
+  // Check connectivity
+  std::set<odb::dbTechLayer*> check_layers;
+  for (const auto& ring : rings_) {
+    for (auto* layer : ring->getLayers()) {
+      check_layers.insert(layer);
+    }
+  }
+  for (const auto& strap : straps_) {
+    check_layers.insert(strap->getLayer());
+  }
+
+  // Check that pin layers actually exists in stack
+  for (auto* layer : pin_layers_) {
+    if (check_layers.find(layer) == check_layers.end()) {
+      getLogger()->error(utl::PDN,
+                         111,
+                         "Pin layer {} is not a valid shape in {}",
+                         layer->getName(),
+                         name_);
+    }
+  }
+
+  // add instance layers
+  const auto nets_vec = getNets();
+  const std::set<odb::dbNet*> nets(nets_vec.begin(), nets_vec.end());
+
+  for (auto* inst : getInstances()) {
+    if (!inst->isFixed()) {
+      continue;
+    }
+    for (auto* iterm : inst->getITerms()) {
+      if (nets.find(iterm->getNet()) != nets.end()) {
+        for (const auto& [layer, shape] : iterm->getGeometries()) {
+          check_layers.insert(layer);
+        }
+      }
+    }
+  }
+  if (domain_->hasSwitchedPower()) {
+    for (const auto& powercell :
+         domain_->getPDNGen()->getSwitchedPowerCells()) {
+      for (auto* mterm : powercell->getMaster()->getMTerms()) {
+        for (auto* mpin : mterm->getMPins()) {
+          for (auto* box : mpin->getGeometry()) {
+            auto* layer = box->getTechLayer();
+            if (layer) {
+              check_layers.insert(layer);
+            }
+          }
+        }
+      }
+    }
+  }
+
+  // add bterms and exisiting routing
+  for (auto* net : nets) {
+    for (auto* swire : net->getSWires()) {
+      for (auto* box : swire->getWires()) {
+        auto* layer = box->getTechLayer();
+        if (layer) {
+          check_layers.insert(layer);
+        }
+      }
+    }
+    for (auto* bterm : net->getBTerms()) {
+      for (auto* bpin : bterm->getBPins()) {
+        if (!bpin->getPlacementStatus().isFixed()) {
+          continue;
+        }
+        for (auto* box : bpin->getBoxes()) {
+          auto* layer = box->getTechLayer();
+          if (layer) {
+            check_layers.insert(layer);
+          }
+        }
+      }
+    }
+  }
+
+  // Check that connect statement actually point to something
+  for (const auto& connect : connect_) {
+    if (check_layers.find(connect->getLowerLayer()) == check_layers.end()) {
+      getLogger()->error(utl::PDN,
+                         112,
+                         "Cannot find shapes to connect to on {}",
+                         connect->getLowerLayer()->getName());
+    }
+    if (check_layers.find(connect->getUpperLayer()) == check_layers.end()) {
+      getLogger()->error(utl::PDN,
+                         113,
+                         "Cannot find shapes to connect to on {}",
+                         connect->getUpperLayer()->getName());
+    }
+  }
 }
 
 void Grid::getObstructions(Shape::ObstructionTreeMap& obstructions) const

src/pdn/src/pdn.tcl

@@ -6,13 +6,15 @@ sta::define_cmd_args "pdngen" {[-skip_trim] \
                                [-reset] \
                                [-ripup] \
                                [-report_only] \
+                               [-check_only] \
                                [-failed_via_report file] \
                                [-verbose]
 } ;#checker off
 
 proc pdngen { args } {
   sta::parse_key_args "pdngen" args \
-    keys {-failed_via_report} flags {-skip_trim -dont_add_pins -reset -ripup -report_only -verbose}
+    keys {-failed_via_report} \
+    flags {-skip_trim -dont_add_pins -reset -ripup -report_only -verbose -check_only}
 
   sta::check_argc_eq0 "pdngen" $args
 
@@ -43,6 +45,13 @@ proc pdngen { args } {
     pdn::report
     return
   }
+  if { [info exists flags(-check_only)] } {
+    if { [array size flags] != 1 } {
+      utl::error PDN 1040 "-check_only flag is mutually exclusive to all other flags"
+    }
+    pdn::check_setup
+    return
+  }
 
   set trim [expr [info exists flags(-skip_trim)] == 0]
   set add_pins [expr [info exists flags(-dont_add_pins)] == 0]

src/pdn/test/BUILD

@@ -25,6 +25,7 @@ COMPULSORY_TESTS = [
     "core_grid_auto_domain_multiple_nets",
     "core_grid_bad_metal_specs",
     "core_grid_check_connect_layers",
+    "core_grid_check_connect_layers_at_setup",
     "core_grid_cut_pitch",
     "core_grid_dual_followpins",
     "core_grid_dual_followpins_error",

src/pdn/test/CMakeLists.txt

@@ -24,6 +24,7 @@ or_integration_tests(
     core_grid_auto_domain_multiple_nets
     core_grid_bad_metal_specs
     core_grid_check_connect_layers
+    core_grid_check_connect_layers_at_setup
     core_grid_cut_pitch
     core_grid_dual_followpins
     core_grid_dual_followpins_error

src/pdn/test/core_grid_check_connect_layers_at_setup.ok

@@ -0,0 +1,9 @@
+[INFO ODB-0227] LEF file: Nangate45/Nangate45.lef, created 22 layers, 27 vias, 135 library cells
+[INFO ODB-0128] Design: gcd
+[INFO ODB-0130]     Created 54 pins.
+[INFO ODB-0131]     Created 482 components and 2074 component-terminals.
+[INFO ODB-0133]     Created 385 nets and 1110 connections.
+[ERROR PDN-0111] Pin layer metal6 is not a valid shape in Core
+PDN-0111
+[ERROR PDN-0113] Cannot find shapes to connect to on metal5
+PDN-0113

src/pdn/test/core_grid_check_connect_layers_at_setup.tcl

@@ -0,0 +1,44 @@
+# test for rejesting incorrect layers at runtime
+source "helpers.tcl"
+
+read_lef Nangate45/Nangate45.lef
+read_def nangate_gcd/floorplan.def
+
+add_global_connection -net VDD -pin_pattern VDD -power
+add_global_connection -net VSS -pin_pattern VSS -ground
+
+set_voltage_domain -power VDD -ground VSS
+
+define_pdn_grid -name "Core" -pins metal6
+add_pdn_stripe -followpins -layer metal1
+add_pdn_stripe -followpins -layer metal2
+
+add_pdn_stripe -layer metal4 -width 0.48 -pitch 15.0 -offset 2.0
+add_pdn_stripe -layer metal7 -width 1.40 -pitch 20.0 -offset 2.0
+
+add_pdn_connect -layers {metal1 metal2}
+add_pdn_connect -layers {metal2 metal4}
+add_pdn_connect -layers {metal4 metal7}
+
+# Check pin layer
+catch { pdngen -check_only } err
+puts $err
+
+pdngen -reset
+
+set_voltage_domain -power VDD -ground VSS
+
+define_pdn_grid -name "Core" -pins metal7
+add_pdn_stripe -followpins -layer metal1
+add_pdn_stripe -followpins -layer metal2
+
+add_pdn_stripe -layer metal4 -width 0.48 -pitch 15.0 -offset 2.0
+add_pdn_stripe -layer metal7 -width 1.40 -pitch 20.0 -offset 2.0
+
+add_pdn_connect -layers {metal1 metal2}
+add_pdn_connect -layers {metal2 metal5}
+add_pdn_connect -layers {metal4 metal7}
+
+# Check connect layer metal5 invalid
+catch { pdngen -check_only } err
+puts $err

src/pdn/test/power_switch.ok

@@ -41,7 +41,6 @@ Straps:
     Snap to grid: false
 Connect:
   Connect layers met1 -> met4
-  Connect layers met2 -> met4
   Connect layers met4 -> met5
 Switched power cell: POWER_SWITCH
   Control net: nPWRUP

src/pdn/test/power_switch.py

@@ -44,7 +44,6 @@
 pdn_aux.add_pdn_stripe(design, layer="met5", width=1.600, pitch=27.200, offset=13.600)
 
 pdn_aux.add_pdn_connect(design, layers=["met1", "met4"])
-pdn_aux.add_pdn_connect(design, layers=["met2", "met4"])
 pdn_aux.add_pdn_connect(design, layers=["met4", "met5"])
 
 design.getPdnGen().report()