Where is PA pattern generation in FlexPA::main in TritonRoute? How to dump out AP info for TA?

[Raynchowkw]

Hi, I want to find the step of "pin access pattern generation" in the TritonRoute/src/pa code and dump out the pattern information after pin access analysis. I don't see pin access pattern generation function in FlexPA::main(). Could anyone tell me where is this step?
Is there template or sample of extracting pin access points information for TA? Thanks.

[maliberty]

The calls to init() and prep() do the work of computing the access points. If you just want to dump the result you would do so after those steps finish. You can just look at frInstTerm::getAccessPoints() for the result.

[Raynchowkw]

Thanks. I think I just got the local build of only openroad, following openroad.git, not the openroad flow following openroad-flow-scripts.git. I think only in the flow can I test with provided sample designs easily, ie. make will run the flow of a specific design. In openroad, I think that is not that easy.

[maliberty]

OpenROAD-flow-scripts just points to the OpenROAD as a submodule. If you can build it in one place you can build it in the other. Its the same program.

[Raynchowkw]

Yes, I understand that OpenROAD is included in OpenROAD-flow-scripts, but successfully building OpenROAD doesn't mean successfully building OpenROAD-flow-scripts. I will try to build the flow again to see if the previous issues are gone after I solve building OpenROAD.
If not, I think my specific plan is to find the equivalent command in OpenROAD to cd flow, make in OpenROAD-flow-scripts, to run the same sample design.

[Raynchowkw]

How to use openroad tool to run the flow? I notice the description of code organization in README of openroad-flow-scripts say that flow contains scripts and reference recipes, so I believe I still can run the flow with openroad tool even though I fail to build openroad flow locally. I want to get the input for TritonRoute by running flow with sample designs, and then run TritonRoute to test the added print out script provided by @Stephanommg before. Am I supposed to copy the 'Makefile' in the openroad-flow-scripts/flow' directory as a .tcl file and use the command './openroad xxx.tcl' to run corresponding steps?

[Raynchowkw]

Hi, I have built the flow locally and made modification to the FlexPA_prep.cpp to add the "cout" code provided by @Stephanommg in previous reply and rebuilt only the openroad tool.
I run 'make' for a sample design, and from the output scripts in terminal, I cannot find any information which is assumed to be produced by 'cout'. I look through the part from '[INFO DRT-0194] start detail routing ...' to '[INFO DRT-0198] complete detail routing', also use "Ctrl+Shift+F" to find "layerNum ", but fail to find any aps information.
Am I supposed to run TritonRoute individually to output the message?

[maliberty]

Btw, what is your high level goal?

[Raynchowkw]

I want to use Openroad flow all the way down until TA. So I want to dump out APs info and put it into other detailed router beginning from TA and see if there is a better way to do detailed routing. I am a student doing a project to graduate.

[maliberty]

Anything on stdout will be copied to the log file in 5_2_TritonRoute.log. Matt

…

On Tue, May 18, 2021 at 2:02 PM Raynchowkw ***@***.***> wrote: Hi, I have built the flow locally and made modification to the FlexPA_prep.cpp to add the "cout" code provided by @Stephanommg <https://github.com/Stephanommg> in previous reply <#625 (reply in thread)> and rebuilt only the openroad tool. I run 'make' for a sample design, and from the output scripts in terminal, I cannot find any information which is assumed to be produced by 'cout'. I look through the part from '[INFO DRT-0194] start detail routing ...' to '[INFO DRT-0198] complete detail routing', also use "Ctrl+Shift+F" to find "layerNum ", but fail to find any aps information. Am I supposed to run TritonRoute individually to output the message? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#625 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAFZ5KTE4I5VLZTMWONFAT3TOLIYFANCNFSM43GD6SBA> .

[Raynchowkw]

Thanks. I rebuild the flow and get the information in the log. I realize I cannot get the change in code function when I only rebuild the openroad tool.

[Raynchowkw]

How to interpret the aps info printed by 'cout << bp << "layerNum " << ap->getLayerNum() << "\n";'?
It looks like: ( the first paragraph)

( ( ( ( ( 84550 23940 )layerNum 2
( 84550 9025072770 23940 )75810layerNum (  ( ( 86450883502 68590 70490 23940
 )239402394023800  )( 23940 )layerNum  23940 )layerNum 272770  )layerNum 
( 86450238002layerNum   )23940layerNum 23800 )2layerNum 
 )2
(  )
( layerNum 70490 23800layerNum 222
( 90250
 )2
( 86450 24080 )68590
layerNum  layerNum ( layerNum ( ( 238002275810 23800

It's not something like (X,Y,Z).
Which part of code should I read to understand this data structure?
How can I know the net_id, pin_id, pin_x, pin_y, pin_layer according to this?
Thanks.

[Stephanommg]

1. The getPins() method called in the for returns some container of pins, you just need to get the size of this container (probably size() method)

2. You can re-implement the operator >> of frPoint in global.cpp or manually print the x and y field of the frPoint separately.

Function definitions are usually on .cpp files.

You need to iterate over the frNets and then iterate over their frInstTerms and frTerms (similar to the for I placed here before). Do this after pin access and before DR. You can do this inf FlexDR::main() before the searchRepair functions. To get all nets, use design_->getTopBlock()->getNets().

I also think you should improve you C++ skills in order to mess with the code.

[Raynchowkw]

Thanks for your reply. They are beyond my understanding now, but I will try to understand them.

1. what's containers? 2. when you say "operator >> of frPoint in global.cpp", do you mean this one?
2. Asking advice on C++ practice and development
   My workflow is: Now I am mostly working on my Windows laptop to do code analysis and editing using sublime text 3 or VSC. Only after careful thinking and making sure there are no mistakes I can find (based on my bare c++ knowledge), will I put it into my another old laptop with centos 7 installed to run the flow.
   Unfortunately, I lost my Windows boot option after I installed centos 7 in my old laptop because of some complicated reasons and I haven't fixed it. So I cannot go back to Windows to assign more disk space for centos 7. It's very constrained in disk space now and it cannot run VSC with unknown reasons. Vim is not efficient in navigation and editing.
   I am too afraid of messing with the code and too meticulous. I just test out my added codes from the print-out information after I run the flow on the old laptop.
   Do you think it is enough for me to practice with c++ to achieve my goal?

[Raynchowkw]

You need to iterate over the frNets and then iterate over their frInstTerms and frTerms (similar to the for I placed here before). Do this after pin access and before DR. You can do this inf FlexDR::main() before the searchRepair functions. To get all nets, use design_->getTopBlock()->getNets().

Is this all for getting the total number of nets? Do I do this "design_->getTopBlock()->getNets()" in the innermost loop for the iteration over frNets->frInstTernms->frTerms or just do it outside the iteration? If it is the latter case, what should I do in the iteration?

[Stephanommg]

By container I meant something that contains things. For instance: a vector.

Yes this operator.

Learning C++ will surely help you. After that you will be better able to understand the code.

I really cant code for you right now, and I think my previous comment already answered you last question (at least in part). You will have to use the first code to iterate the access points in combination with the last code to iterate over the nets.

for each net
for each instTerm
get access points like the 1st code
for each term
get access points like the 1st code (with differences that it is up to up to check)

[Raynchowkw]

You need to iterate over the frNets and then iterate over their frInstTerms and frTerms (similar to the for I placed here before). Do this after pin access and before DR. You can do this inf FlexDR::main() before the searchRepair functions. To get all nets, use design_->getTopBlock()->getNets().

Hi, I want to dump out aps before TA. I check TritonRoute::main. dr is later than ta. So I want to dump out at the end of FlexPA::main. Would that incur unexpected problems?

[Raynchowkw]

Thanks.

…

On Fri, May 28, 2021 at 5:36 PM Stephanommg ***@***.***> wrote: By container I meant something that contains things. For instance: a vector. Yes this operator. Learning C++ will surely help you. After that you will be better able to understand the code. I really cant code for you right now, and I think my previous comment already answered you last question (at least in part). You will have to use the first code to iterate the access points in combination with the last code to iterate over the nets. for each net for each instTerm get access points like the 1st code for each term get access points like the 1st code (with differences that it is up to up to check) — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#625 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANTC4GJTDN2RNSJW4YS7Z43TQALHXANCNFSM43GD6SBA> .

-- Best, Raynchow

[Raynchowkw]

Here is my new version of modification of FlexDR.cpp (Line 1983 to 2023), with error that make my build failing.

int FlexDR::main()
{
  ProfileTask profile("DR:main");
  init();
  frTime t;
  if (VERBOSE > 0) {
    logger_->info(DRT, 194, "start detail routing ...");
  }

  //dump out PA in Labyrinth format
  ////get total # of nets in design
  cout << "start dumping out aps";
  int net_id = 0;
  //cout<<"net num "<<net_num<<"\n";
  cout<<"net num "<<getDesign()->getTopBlock()->getNets().size()<<"\n";//may need int()

  for (auto& net : getDesign()->getTopBlock()->getNets()) {
    //pin_num_in_net = ?
    int pin_num_in_net = 0;
    //consider to calculate "pin_num_in_net" earlier
    cout<< net->getName() << " "<< net_id++ << " " << "pin_num_in_net " << "min_wid";
    for (auto& instTerm : net->getInstTerms()) {
      if (isSkipInstTerm(instTerm.get())) {
        continue;
      }   
      //get pin size in each Term, accumulate it to get pin # in each Net
      int pin_size_in_Term=(int) (instTerm->getTerm()->getPins().size());
      pin_num_in_net += pin_size_in_Term;

      //first code
      frTransform shiftXform;
       inst->getTransform(shiftXform);
       shiftXform.set(frOrient(frcR0));
       if (!instTerm->hasNet())
           continue;
       for (auto& pin : instTerm->getTerm()->getPins()) {
           if (!pin->hasPinAccess()) {
             continue;
           }
           
           //print pin name, pin_id
           for (auto& ap : pin->getPinAccess(inst->getPinAccessIdx())->getAccessPoints()) {
             frPoint bp;
             ap->getPoint(bp);
             bp.transform(shiftXform);
             cout << bp << "layerNum " << ap->getLayerNum() << " " << design_->getTech()->getLayer(ap->getLayerNum())->getName() <<"\n";
           }
       }       
    }
    cout << "pin_num_in_net" <<net_id - 1<<"=" << pin_num_in_net;
  }

[Raynchowkw]

I copy the error when I build here.

/home/rayncc/my_opr/OpenROAD-flow-scripts/tools/OpenROAD/src/TritonRoute/src/dr/FlexDR.cpp: In member function ‘int fr::FlexDR::main()’:
/home/rayncc/my_opr/OpenROAD-flow-scripts/tools/OpenROAD/src/TritonRoute/src/dr/FlexDR.cpp:1996:35: error: request for member ‘get’ in ‘instTerm’, which is of pointer type ‘fr::frInstTerm* const’ (maybe you meant to use ‘->’ ?)
       if (isSkipInstTerm(instTerm.get())) {
                                   ^~~
/home/rayncc/my_opr/OpenROAD-flow-scripts/tools/OpenROAD/src/TritonRoute/src/dr/FlexDR.cpp:1996:11: error: ‘isSkipInstTerm’ was not declared in this scope
       if (isSkipInstTerm(instTerm.get())) {
           ^~~~~~~~~~~~~~
/home/rayncc/my_opr/OpenROAD-flow-scripts/tools/OpenROAD/src/TritonRoute/src/dr/FlexDR.cpp:1996:11: note: suggested alternative: ‘instTerm’
       if (isSkipInstTerm(instTerm.get())) {
           ^~~~~~~~~~~~~~
           instTerm
/home/rayncc/my_opr/OpenROAD-flow-scripts/tools/OpenROAD/src/TritonRoute/src/dr/FlexDR.cpp:2005:8: error: ‘inst’ was not declared in this scope
        inst->getTransform(shiftXform);
        ^~~~
/home/rayncc/my_opr/OpenROAD-flow-scripts/tools/OpenROAD/src/TritonRoute/src/dr/FlexDR.cpp:2005:8: note: suggested alternative: ‘init’
        inst->getTransform(shiftXform);
        ^~~~
        init

I think the "isSkipInstTerm" is not defined in FlexDR.cpp. It's defined in L1807 in FlexPA_prep.cpp. Do I need to include it or just comment it out here?

[Raynchowkw]

I have no idea how to get inst here. In the first code, Inst is got from Insts in the argument. And InstTerm is got from Inst. Here I just get InstTerm from net.
As you said, after looping InstTerm, loop Term. But I don't know of of get rid of inst for the "first code".

[Stephanommg]

Please, if you have basic knowledge of EDA then search a little in the classes related to what you want. For example, you want an inst, and you have an instTerm. An instTerm is related to an inst so it is intuitive to look in frInstTerm for a getInst() method (or something like). And, in fact, there is such method.

I am not sure whether skipInstTerm is necessary here. Just commentit for now.

If you want to access a method of an object through a point, then you should use -> instead of . (dot). (C/C++ basics)

If you want the total number of real pins in the net, just:
net.getInstTerms() + net.getTerms()

The instTerms of a net are the std cell and macro block pins, and the terms of a net are the IO pins. I said before "real pins" because what TritonRoute calls pins is not necessarily the real pins.

[Raynchowkw]

Thank you so much. I not an EDA person. I am a hardware designer. But I know your meaning from analyzing the code. I know the logic to see their class to find "getter" to get one from another and if it is a pointer, I need to use ->.
However, I don't know the relationship between inst, instTerm, Term, as they can "get" one another. So I don't know the order to loop over them.
For example, in FlexPA::genInstPattern_print, it get inst by auto& inst = insts[currIdx1], and then you do

for (auto& instTerm : inst->getInstTerms()) {
  for (auto& pin : instTerm->getTerm()->getPins()) {
    for (auto& ap : pin->getPinAccess(inst->getPinAccessIdx())->getAccessPoints()) {
...

to loop over ap.
So I think inst > instTerm > Term > pin > ap. By ">" I mean inst contains multiple InstTerm, forexample. I don't know it's container relationship or one-to-one mapping relationship.
In FlexDR::main, I getNets first. In class frNet, there is only getInstTerms, no getInst, so I getInstTerm first. So I am not sure whether to flip the loop order, for example, to transfer for (auto& instTerm : inst->getInstTerms()) into for (auto &inst: insTerm->getInst())?
From your description of the loop order before:
for each net
for each instTerm
get access points like the 1st code
for each term
get access points like the 1st code (with differences that it is up to up to check)
You means I don't need to loop inst back from InstTerm, right?
And because term and instTerm are different unrelated things, they should be looped over separately, right?
But in your first code,

for (auto& instTerm : inst->getInstTerms()) {
  for (auto& pin : instTerm->getTerm()->getPins()) {

you just get access points in Terms, right?
Thanks.

[maliberty]

@Raynchowkw the project has limited resources and I think you need to put in more effort to solve your issues before requesting help. Many of the requests don't require in depth knowledge of OpenRoad and are basic software development skills you need to develop.

[Raynchowkw]

Yes, I know. Thanks for your advice. I really appreciate your time and effort on maintaining this project. I have been improving my software development skills everyday. I will only ask when I am stuck with the concepts in the code (like the meaning of pin is a little confused if I understand it traditionally).
I think I almost get it. Just two weeks left for me. I will try my best before I ask.
Thanks for the long-term help.

[maliberty]

You can think of a term as a port of a verilog module; an instance as an instance of a verilog module; and an instTerm as the connection point on the instance reflecting the port of the module instantiated.

[Raynchowkw]

Thanks.

[Raynchowkw]

Can I use net.getInstTerms()->getTerms()->getpins().size() + net.getTerms()->getpins().size() to get the number of pin in a net?

[maliberty]

there is no getTerm()->getPins() as the first is a collection which you need to iterate over.

[maliberty]

Your question suggests you aren't even looking at the code or trying your ideas before asking. Again please make more of an effort yourself.

[Raynchowkw]

OK.

[Raynchowkw]

Hi, After working hard on learning C++, I still have some questions.
One that blocks my understanding is pin.get() etc.
What's the .get() here and where's its definition? I cannot find one in their class def.

[Raynchowkw]

Does FlexPA::genInstPattern also generate aps for IO Terms?
In FlexPA::genInstPattern_commit, in //update instTerm ap, I just see it gets InstTerms.
Does frNet.getTerms() get IO terms and frNet.getInstTerms() get standard cells terms?

[Raynchowkw]

Stephan's first code also just considers cell instances, so I think the cell instances's Pin access is the interest of the PAAF in TritonRoute, right? IO Terms' pins' aps are handled in another way, not by dynamic-based scheme, right?

[maliberty]

The top level terminals are generally just simple rects that we use planar access to. There isn't much need for complex analysis.

Does frNet.getTerms() get IO terms and frNet.getInstTerms() get standard cells terms? Yes

[Raynchowkw]

Thanks. Could you help me understand a little bit about the usage of frTransform and frPoint? I think they are to get the coordinate of points in an instance. In the first code:

 frTransform shiftXform;
 inst->getTransform(shiftXform);
 shiftXform.set(frOrient(frcR0));
///iterate over pin of instTerm->Term
    for (auto& ap : pin->getPinAccess(inst->getPinAccessIdx())->getAccessPoints()) {
       frPoint bp;
       ap->getPoint(bp);
       bp.transform(shiftXform);
///cout

Does this kind of Transform of point location message only work in the unit of Inst?
From net, it can directly get InstTerm. For each InstTerm I can get Inst.
Do I need to get Inst for each InstTerm in order to dump out their aps information in form of "aps.x aps.y aps_layer"?
In my understand, a net connects some InstTerms, and each InstTerm belong to its own Inst, and aps information should be dumped out based on Inst, right?

[maliberty]

If you have a copy of the OpenAccess docs they have a good description of transforms. The transform mechanism is generic but it is generally used with instances.

APs are per instance.

[maliberty]

No problem

…

On Thu, Jun 10, 2021 at 11:48 AM Raynchowkw ***@***.***> wrote: You need to iterate over the frNets and then iterate over their frInstTerms and frTerms (similar to the for I placed here before). Do this after pin access and before DR. You can do this inf FlexDR::main() before the searchRepair functions. To get all nets, use design_->getTopBlock()->getNets(). Hi, I want to dump out aps before TA. I check TritonRoute::main. dr is later than ta. So I want to dump out at the end of FlexPA::main. Would that incur unexpected problems? — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#625 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAFZ5KQZ53CPKQFIDDJZWCLTSECHPANCNFSM43GD6SBA> .

[maliberty]

a smart pointer is just a wrapper around a regular pointer. If you have the regular pointer you don't need to use .get().

[Raynchowkw]

OK I see. So I just do isSkipInstTerm(instTerm).

[Raynchowkw]

Does one pin has multiple pin access points after pa?
For nangate45/gcd, when I print out aps information in each pin in each net, for each pin, it has 3 aps.
I think it is because this line in the first code.
for (auto& ap : pin->getPinAccess(inst->getPinAccessIdx())->getAccessPoints()) {
getPinAccess returns frPinAccess* aps_[idx], then getAccessPoints() returns vector aps_.
While in FlexPA::genInstPattern_commit, it just set one ap_ for each pin by instTerm->setAccessPoint(pinIdx, accessPoint);.
In the paper, it also says after pattern selection, it has one ap for each pin.
I am confused about this.
Could you help me? Thanks.

[Raynchowkw]

I read FlexPA::prep()'s prepPattern and its genPattern, genInstPattern.
Is genPattern_commit doing selection of pattern and getting one AccessPoint for each pin?
Is this snippet of code doing this job?

    for (int idx1 = 0; idx1 < (int) pins.size(); idx1++) {
      auto idx2 = accessPattern[idx1];
      auto& [pin, instTerm] = pins[idx1];
      auto inst = instTerm->getInst();
      targetObj = inst;
      int paIdx = unique2paidx_[inst];
      auto pa = pin->getPinAccess(paIdx);
      auto accessPoint = pa->getAccessPoint(idx2);
      pin2AP[pin] = accessPoint;

Thanks.

[Raynchowkw]

I see similar snippets in genPatterns_print and genPatterns_print_debug.
In my understanding, it takes selected pattern in unique instances to map a specific instance, and then get the selected ap by auto pa = pin->getPinAccess(paIdx), and then frPoint pt(pa->getAccessPoint(currIdx2)->getPoint()); gets the point's location.
Do I understand correctly?

[Raynchowkw]

After one week of understanding code, I find the logic of assigning one ap to one pin by this line in genInstPattern_commit.
The code @Stephanommg wrote to get aps is for (auto& ap : pin->getPinAccess(inst->getPinAccessIdx())->getAccessPoints()). I had a hard time understanding what frPinAccess is doing. I just find its uses in the FlexPA::initPinAccess in and FlexPA::prepPoint in FlexPA::prepPattern and revertAccessPoints and prepPattern_inst.
It looks like these are before genInstPattern_commit and just for coord manipulation purpose. So I think frPinAccess doesn't filter ap selected for each pin.
So in order to get ap for each pin in each net, can I do loop through net -> instTerms ->getAccessPoints() ?
I am not sure the meaning of "net" and what's relationship between pin and net. Can I understand as this: a net connects some instTerms, each instTerm has some pins, so instTerms' pins are linked to that one net exclusively? Or pins in one instTerm can be linked to
different nets?
Thanks.

[Stephanommg]

Yes each pin may have more than 1 ap.

A net is the element that interconnect the pins, and is implemented by wires connecting the pins.
"Can I understand as this: a net connects some instTerms, each instTerm has some pins, so instTerms' pins are linked to that one net exclusively? "
Yes. instTerm and possibly terms.
"Or pins in one instTerm can be linked to different nets?"
No.

I think the answer on how to get the aps was already given.

[Raynchowkw]

Thanks a lot.
I am still confused why each pin may have multiple aps.
In the Tao of PAO paper, it says: "for each unique instance, an access pattern consists of one access point per pin.
After cluster-based access pattern selection, only one access pattern is remained for each inst.
The corresponding code part is FlexPA::genInstPattern.
In genInstPattern_perform, it gets one access pattern for each inst. In genInstPattern_commit, it set ap for each pin by this snippet:

      // update instTerm ap
      for (auto& instTerm : inst->getInstTerms()) {
        if (isSkipInstTerm(instTerm.get())) {
          continue;
        }

        int pinIdx = 0;
        // to avoid unused variable warning in GCC
        for (int i = 0; i < (int) (instTerm->getTerm()->getPins().size());
             i++) {
          auto& accessPoint = accessPoints[accessPointIdx];
          instTerm->setAccessPoint(pinIdx, accessPoint);
          pinIdx++;
          accessPointIdx++;
        }
      }

It seems in one instTerm, one pin id corresponds to one ap.
If one pin is not shared by different instTerm, it should be one ap for one pin, right?

---

For understanding of net, as it's wires connecting different pins, why "pin_1 in instTerm1 connects net1, pin_2 in instTerm1 connects net2" won't happen? I also hope this won't happen because this simplifies the problem.

[maliberty]

In the paper that is referring to an "Access Pattern" which is a set of compatible APs. Each pin may have many access points (see III.A) from which one is selected per access pattern (see III.B).

[Raynchowkw]

I know that in III.A there are aps (access points) for each pin and after III.B there are multiple access patterns for one inst. I just want to dump out the only ap (access point) of each pin in the only one access pattern of inst it belongs to, selected in III.C, in a form of grouping by net.

[Raynchowkw]

Am I right?