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dbSta: check LEF and Liberty area consistency #11620

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dbSta: check LEF and Liberty area consistency #11620

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3 changes: 2 additions & 1 deletion src/dbSta/include/db_sta/IpChecker.hh
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Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@ namespace sta {
// LEF-CHK-010b: Pin minimum area
// LEF/LIB-CHK-011: Pin direction matches Liberty
// LEF/LIB-CHK-012: LEF macros and signal pins exist in Liberty
// LEF/LIB-CHK-013: LEF and Liberty cell areas match

class IpChecker
{
Expand Down Expand Up @@ -90,7 +91,7 @@ class IpChecker
// LEF-CHK-010b: Pin minimum area
void checkPinMinArea(odb::dbMaster* master);

// LEF/LIB-CHK-011-012: Check Liberty pin presence and direction
// LEF/LIB-CHK-011-013: Check Liberty pin presence, direction, and area
void checkLibertyPins(odb::dbMaster* master);

// Helper: Check if a pin shape has at least one accessible edge
Expand Down
22 changes: 22 additions & 0 deletions src/dbSta/src/IpChecker.cc
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Expand Up @@ -5,6 +5,7 @@

#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstddef>
#include <cstdint>
#include <cstdlib>
Expand Down Expand Up @@ -792,6 +793,27 @@ void IpChecker::checkLibertyPins(odb::dbMaster* master)
return;
}

odb::dbTech* tech = db_->getTech();
if (tech != nullptr) {
const double dbu_per_micron = tech->getDbUnitsPerMicron();
const double lef_area
= static_cast<double>(master->getWidth()) * master->getHeight()
/ (dbu_per_micron * dbu_per_micron);
const double liberty_area = liberty_cell->area();
const double area_tolerance = std::max(1e-6, lef_area * 1e-3);

if (std::abs(lef_area - liberty_area) > area_tolerance) {
logger_->warn(utl::CHK,
122,
"Master {} area mismatch between LEF ({:.6f}) and "
"Liberty ({:.6f})",
master_name,
lef_area,
liberty_area);
warning_count_++;
}
Comment on lines +798 to +814

@gemini-code-assist gemini-code-assist Bot Oct 3, 2026

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medium

If dbu_per_micron is 0 (which can happen if the database units are not properly initialized or defined in the LEF), dividing by it will result in a division-by-zero error, producing inf or nan values. Adding a guard to ensure dbu_per_micron > 0 before performing the division is a safer and more robust approach.

    const double dbu_per_micron = tech->getDbUnitsPerMicron();
    if (dbu_per_micron > 0) {
      const double lef_area
          = static_cast<double>(master->getWidth()) * master->getHeight()
            / (dbu_per_micron * dbu_per_micron);
      const double liberty_area = liberty_cell->area();
      const double area_tolerance = std::max(1e-6, lef_area * 1e-3);

      if (std::abs(lef_area - liberty_area) > area_tolerance) {
        logger_->warn(utl::CHK,
                      122,
                      "Master {} area mismatch between LEF ({:.6f}) and "
                      "Liberty ({:.6f})",
                      master_name,
                      lef_area,
                      liberty_area);
        warning_count_++;
      }
    }

}

for (odb::dbMTerm* mterm : master->getMTerms()) {
if (mterm->getSigType().isSupply()) {
continue;
Expand Down
23 changes: 23 additions & 0 deletions src/dbSta/test/check_ip_liberty_pins.lef
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Expand Up @@ -135,4 +135,27 @@ MACRO lef_lib_direction_mismatch
END VDD
END lef_lib_direction_mismatch

MACRO lef_lib_area_mismatch
CLASS BLOCK ;
ORIGIN 0 0 ;
SIZE 1.000 BY 1.000 ;
PIN A
DIRECTION INPUT ;
USE SIGNAL ;
ANTENNAMODEL OXIDE1 ;
PORT
LAYER M1 ;
RECT 0.100 0.100 0.300 0.300 ;
END
END A
PIN VDD
DIRECTION INOUT ;
USE POWER ;
PORT
LAYER M1 ;
RECT 0.000 0.000 1.000 0.200 ;
END
END VDD
END lef_lib_area_mismatch

END LIBRARY
12 changes: 12 additions & 0 deletions src/dbSta/test/check_ip_liberty_pins.lib
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Expand Up @@ -45,4 +45,16 @@ library (check_ip_liberty_pins) {
voltage_name : VDD;
}
}

cell (lef_lib_area_mismatch) {
area : 2;
pin (A) {
capacitance : 0.001;
direction : input;
}
pg_pin (VDD) {
pg_type : primary_power;
voltage_name : VDD;
}
}
}
1 change: 1 addition & 0 deletions src/dbSta/test/check_ip_liberty_pins.tcl
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Expand Up @@ -27,5 +27,6 @@ expect_check_ip_pass lef_lib_pins_match
expect_check_ip_fail lef_lib_pin_missing
expect_check_ip_fail lef_lib_cell_missing
expect_check_ip_fail lef_lib_direction_mismatch
expect_check_ip_fail lef_lib_area_mismatch

puts "pass"
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