misc: better support for soft halos by openroad-ci · Pull Request #9837 · The-OpenROAD-Project/OpenROAD

openroad-ci · 2026-03-19T17:30:53Z

This PR adds support for DEF soft halos across OpenROAD.

Modifies ODB to add a flag to dbBox to mark it as a soft or hard halo for dbInst
Modifies GPL/CTS to correctly consider halos during placement of instances
- GPL cannot put instances within any halo, CTS can put instances in soft halos
Small bugfix on PDN regarding halo copy from ODB to PDN and use getTransformedHalo
- PDN considers only hard halos
Adjust cutRows function to use getTransformedHalo
- cutRows also is only concerted with hard halos

Signed-off-by: João Mai <jmai@precisioninno.com>

gemini-code-assist

Code Review

This pull request introduces support for soft halos for instances, a feature that is now reflected across various parts of the OpenROAD flow. The changes correctly modify ODB to store a soft flag for halos, update the DEF parser and writer to handle the SOFT keyword, and adjust tools like CTS, GPL, and PDN to respect hard vs. soft halos as per their requirements. The logic seems sound and consistent across all modified components. Additionally, a bug fix for orientation handling in mpl is included. I have one suggestion for a minor performance and style improvement in src/odb/src/zutil/util.cpp.

gemini-code-assist · 2026-03-19T17:37:36Z

src/odb/src/zutil/util.cpp

  if (blockage->getOwnerType() == odb::dbBoxOwner::INST) {
    halo = static_cast<odb::dbInst*>(blockage->getBoxOwner())->getHalo();
+    transformed_halo = static_cast<odb::dbInst*>(blockage->getBoxOwner())
+                           ->getTransformedHalo();
  }


This block of code has a couple of minor inefficiencies:

static_cast<odb::dbInst*>(blockage->getBoxOwner()) is performed twice.

getTransformedHalo() is called even if the halo is null or soft. This call is unnecessary in those cases.

Consider refactoring to store the instance pointer and only call getTransformedHalo() when it's confirmed to be a hard halo. Note that for dbBoxOwner::INST, getBoxOwner() is guaranteed to return a valid instance.

Suggested change

if (blockage->getOwnerType() == odb::dbBoxOwner::INST) {

halo = static_cast<odb::dbInst*>(blockage->getBoxOwner())->getHalo();

transformed_halo = static_cast<odb::dbInst*>(blockage->getBoxOwner())

->getTransformedHalo();

}

if (blockage->getOwnerType() == odb::dbBoxOwner::INST) {

auto* inst = static_cast<odb::dbInst*>(blockage->getBoxOwner());

halo = inst->getHalo();

if (halo != nullptr && !halo->isSoft()) {

transformed_halo = inst->getTransformedHalo();

}

}

References

A dbBox with owner type dbBoxOwner::INST will always have a valid owner instance; getBoxOwner() will not return null.

github-actions · 2026-03-19T17:49:40Z

clang-tidy review says "All clean, LGTM! 👍"

Signed-off-by: João Mai <jmai@precisioninno.com>

github-actions · 2026-03-19T18:17:29Z

clang-tidy review says "All clean, LGTM! 👍"

gadfort · 2026-03-19T18:55:38Z

src/odb/src/db/dbBox.h

 {
  dbBoxOwner::Value owner_type : 4;
-  uint32_t visited : 1;
+  uint32_t soft : 1;


is this a safe change for the DB? or should this require a version bump?

The visited flag is unused, so I think it is safe.

gadfort · 2026-03-19T18:59:21Z

src/pdn/src/grid.cpp

-
-    odb::Rect inst_box = inst->getBBox()->getBox();
+  if (halo != nullptr && !halo->isSoft()) {
+    odb::Rect halo_box = inst->getTransformedHalo();


somethings off about this.
What is actually stored in the halo_? It was the deltaX, and deltaY of the instance (ie. the halo), but looking at the getTransformedHalo that seems to be doing something completely different

halo_ stores the values of left, bottom, right and top spacing as positive values in xMin, yMin, xMax and yMax respectively. getTransformedHalo returns the halo re-oriented considering the instance orientation.

AcKoucher · 2026-03-19T20:31:05Z

src/gui/src/renderThread.cpp

+    odb::Rect halobox = inst->getTransformedHalo();
+    Rect instbox = inst->getBBox()->getBox();


Why removing the check?

AcKoucher · 2026-03-19T20:33:57Z

src/mpl/src/object.cpp

  switch (getOrientation().getValue()) {
    case odb::dbOrientType::Value::R180:
-    case odb::dbOrientType::Value::MX:
+    case odb::dbOrientType::Value::MY:


It would have been good to include this bug fix in the description as well.

joaomai added 14 commits March 19, 2026 16:24

mpl: fix getRealLocation

e60d363

Signed-off-by: João Mai <jmai@precisioninno.com>

odb: support for soft halo

2b95439

Signed-off-by: João Mai <jmai@precisioninno.com>

odb/gui: write and draw halo correctly

b61faf3

Signed-off-by: João Mai <jmai@precisioninno.com>

mpl: create inst halo for all macros

c3149f7

Signed-off-by: João Mai <jmai@precisioninno.com>

cts: support macro halos

79eccff

Signed-off-by: João Mai <jmai@precisioninno.com>

odb: cutRows correctly uses halo orientation

e9a8d36

Signed-off-by: João Mai <jmai@precisioninno.com>

pdn: correctly use macro halos

eaa4bbc

Signed-off-by: João Mai <jmai@precisioninno.com>

gpl: consider macro halos as blockages

8e74559

Signed-off-by: João Mai <jmai@precisioninno.com>

formatting

2c31283

Signed-off-by: João Mai <jmai@precisioninno.com>

mpl: create blockages for halos

0dea6b8

Signed-off-by: João Mai <jmai@precisioninno.com>

formatting

8f941d4

Signed-off-by: João Mai <jmai@precisioninno.com>

pdn: consider only hard halos

7bae9e2

Signed-off-by: João Mai <jmai@precisioninno.com>

mpl: remove blockage creation in MPL

6c9fd47

Signed-off-by: João Mai <jmai@precisioninno.com>

formatting

e2771bb

Signed-off-by: João Mai <jmai@precisioninno.com>

openroad-ci assigned joaomai Mar 19, 2026

gemini-code-assist bot reviewed Mar 19, 2026

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update PDN doc

38ea719

Signed-off-by: João Mai <jmai@precisioninno.com>

joaomai requested review from AcKoucher and maliberty March 19, 2026 18:07

gadfort reviewed Mar 19, 2026

View reviewed changes

AcKoucher reviewed Mar 19, 2026

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misc: better support for soft halos#9837

misc: better support for soft halos#9837
openroad-ci wants to merge 15 commits intoThe-OpenROAD-Project:masterfrom
The-OpenROAD-Project-staging:mpl-halo-blockages

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		odb::Rect halobox = inst->getTransformedHalo();
		Rect instbox = inst->getBBox()->getBox();

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