PSM power grid check lists false-positive disconnected nodes inside macros

[donn]

Describe the bug

Trying a smoke-test multi-macro design with core rings: check_power_grid -net VPWR reports a multitude of disconnected PDN nets. Key is, the nets are not in fact disconnected there are vias at the claimed location: see this example

When disabling the check, the design does indeed pass LVS.

Expected Behavior

A design passing LVS should not fail the PSM power grid check.

Environment

Git commit: 75f2f325b7a42e56a92404f33af8e96530d9b202
kernel: Darwin 23.1.0
os: macOS 14.1.1
cmake version 3.27.7
CMake Deprecation Warning at third-party/abc/CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.5 will be removed from a future version of
  CMake.

  Update the VERSION argument <min> value or use a ...<max> suffix to tell
  CMake that the project does not need compatibility with older versions.


CMake Warning:
  Manually-specified variables were not used by the project:

    VERBOSE


-- The CXX compiler identification is Clang 16.0.6
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-- boost: 1.83.0
-- Found Python3: /nix/store/7b0rz3bnx7msw2wawkv1hhn5lqf1b0wi-python3-3.11.6/include/python3.11 (found version "3.11.6") found components: Development Development.Module Development.Embed 
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-- spdlog: 1.12.0
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-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE) 
-- STA version: 2.4.0
-- STA git sha: 5b374dd36ad345c9fcd5224e9fc20484393568ab
-- System name: Darwin
-- Compiler: Clang 16.0.6
-- Build type: RELEASE
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-- Found re2: /nix/store/hpdlfnhcp4xpc0y2kn2z7644ksy46mz6-re2-2023-11-01-dev/lib/cmake/re2/re2Config.cmake (found version "11.0.0") 
-- Found GLPK: /nix/store/xh65x0zq6ni7dkb1dymdrahxll81ma8m-glpk-5.0/lib/libglpk.dylib  
-- Found OpenMP_CXX: -fopenmp=libomp (found version "5.0") 
-- Found OpenMP: TRUE (found version "5.0")  
-- GPU is not enabled
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-- GUI is enabled
-- Charts widget is not enabled
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-- Found Boost: /nix/store/vf1zzbfy97i3awvva9yb2559vii2vc47-boost-1.83.0-dev/lib/cmake/Boost-1.83.0/BoostConfig.cmake (found suitable version "1.83.0", minimum required is "1.78")  
-- TCL library: /nix/store/l1rhkhykl3vzqipkk1c7wm6qanswxnrk-tcl-8.6.13/lib/libtcl.dylib
-- TCL header: /nix/store/l1rhkhykl3vzqipkk1c7wm6qanswxnrk-tcl-8.6.13/include/tcl.h
-- Found Boost: /nix/store/vf1zzbfy97i3awvva9yb2559vii2vc47-boost-1.83.0-dev/lib/cmake/Boost-1.83.0/BoostConfig.cmake (found version "1.83.0") found components: serialization system thread 
-- Removing MPL2 and PAR to avoid run time fatal error.
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-- Python3 enabled
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-- Configuring done (12.0s)
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-- Build files have been written to: /tmp/tmp.iWDflSEtcm

To Reproduce

You may use the very short ./run.sh or load the odb into the GUI:

repro.tgz

Relevant log output

No response

Screenshots

No response

Additional Context

No response

[maliberty]

I believe LVS passes but the design is oddly constructed. The instance has pins: while at the top level you have: They shapes are connected only through the instance pin shapes. Is this intended? How was this grid constructed?

[donn]

@maliberty Apologies for the late response. Here's the reproducible for the top-level PDN generation:

repro.tgz

Fully expecting something here to not make sense given your confusion 😅

[maliberty]

any response to "Is this intended? How was this grid constructed?"

[maliberty]

nvm

[maliberty]

@gadfort any thoughts on this? It appears to be trying to connect the shapes that in the ring pin of the instance. Oddly it doesn't happen in both rings.

[maliberty]

@gadfort your shape merging idea would fix the psm issue here.

[gadfort]

@maliberty Ill take a look tomorrow if I can