01:00 <litghost> kgugala: https://github.com/SymbiFlow/symbiflow-arch-defs/pull/404 This helps with the carry pack test, but picosoc never packs. Some sort of infinite loop in the packer?

01:00 <tpb> Title: Remove second chain from each CLB. by litghost · Pull Request #404 · SymbiFlow/symbiflow-arch-defs · GitHub (at github.com)

03:11 <sf-slack> <kgugala> I think the hang is happening in the prepacking

03:12 <sf-slack> <kgugala> @litghost does it happen with the current chain_pack test (8 counters, 8 bit each)?

03:12 <litghost> It is

03:12 <sf-slack> <kgugala> I'm traveling today, @acomodi can you take a look on that?

08:34 <sf-slack> <acomodi> kgugala, litghost: Sure, I have found out the problem is in the pattern selection, the prepacker fails to create a molecule of the carrychain

08:34 <sf-slack> <acomodi> I'll keep you updated

13:09 <sf-slack> <acomodi> I have found what is the issue in the with the infinite loop. Basically the carry atoms are not packed in order into the molecule (e.g. `cur_molecule->atom_ids = {id = 1944, id = 1955, id = 1966, id = 1975}`)

13:16 <sf-slack> <acomodi> I am currently using VPR from PR https://github.com/SymbiFlow/vtr-verilog-to-routing/pull/9. in function `alloc_and_load_pack_molecules` when there is a chain the `do - while` will jump with the `blk_iter` of the number of atoms that have been packed ahead and continue the loop until the chain is completed. The problem here is that this jump will get the iterator pointing to a block which is not a carry0 root block,

13:16 <sf-slack> making the creation of the next molecule unfeasible

13:16 <tpb> Title: Sign in to GitHub · GitHub (at github.com)

13:49 <sf-slack> <kgugala> So maybe if we get a chain atom we should always find it's root and pack the whole molecule

15:36 <sf-slack> <acomodi> @litghost, @kgugala: So, I found a solution that gets past the infinite loop. Basically, when packing a chain molecule, I inserted a mechanism to find the next block of the chain (which should be a root one) and continue packing the molecule with the same `pack_pattern` until the no further block is found for the chain.

15:36 <sf-slack> https://github.com/SymbiFlow/vtr-verilog-to-routing/pull/9/commits/9c69b83408714340a0b3bd1b6cc2b9187ca02c73

15:36 <tpb> Title: [WIP] round robin packing by kgugala · Pull Request #9 · SymbiFlow/vtr-verilog-to-routing · GitHub (at github.com)

15:41 <sf-slack> <kgugala> @acomodi the change looks fine

15:42 <sf-slack> <kgugala> Can you try building the picosoc with this one and @litghost's changes

15:43 <sf-slack> <acomodi> Yep, I have been trying that right away and got into an issue in the following step which is the cluster creation I suppose. I'll get back to you with further info in a bit

15:45 <sf-slack> <kgugala> Can you try building the chain test, but with 24 bit long counters?

15:45 <sf-slack> <kgugala> The chain_test after litghost modification

15:46 <sf-slack> <kgugala> Where we have 8 counters

15:46 <sf-slack> <acomodi> Sure

15:47 <sf-slack> <acomodi> For now these are some examples of the packing that was done with my modifications with the `picosoc` test: https://pastebin.com/7GGucpsx

15:47 <tpb> Title: molecule type: BLK_TI-CLBLL_R.BLK_IG-SLICEL0.CARRYCHAIN pattern index 0 - Pastebin.com (at pastebin.com)

15:49 <sf-slack> <kgugala> Can you also paste prepack echo file?

15:54 <sf-slack> <acomodi> Here is the picosoc prepack echo file

15:54 <sf-slack> <kgugala> Please use pastebin

15:56 <sf-slack> <acomodi> Right, the problem is that it exceeds 512kb, give me a sec

15:59 <sf-slack> <acomodi> https://pastebin.com/sQLBHCJG there are all the carrychains molecules here

15:59 <tpb> Title: molecule type: BLK_TI-CLBLL_R.BLK_IG-SLICEL0.CARRYCHAIN pattern index 0: atom - Pastebin.com (at pastebin.com)

16:01 <sf-slack> <acomodi> And this is the one obtained with the `chain_packing` test: https://pastebin.com/0wPeyTfC (which is still computing though)

16:01 <tpb> Title: # of pack patterns 16 pack pattern index 0 block count 7 name LUT5toLUT7 root B - Pastebin.com (at pastebin.com)

16:04 <sf-slack> <acomodi> `chain_packing` with 24 bit counter and 8 different counters has been routed, I'll check it on HW now

16:13 <sf-slack> <acomodi> update: 8 counters with 24 bit each work on HW

16:14 <sf-slack> <kgugala> Great

16:18 <sf-slack> <acomodi> This is the picosoc build fail error message: `Can not find any logic block that can implement molecule. Atom soc.cpu.cpuregs.regs.22.0.1.stub (DRAM_2_OUTPUT_STUB)`

16:30 <mithro> litghost / kgugala: https://docs.google.com/document/d/1LQ0H2C9IFnCVtSuaniCs1dDmBoMBWwBQLKAGuo_kSc0/edit#heading=h.sjrs4z6k5261

16:30 <tpb> Title: VPR Proposal for supporting equivalent placement types - Google Docs (at docs.google.com)

16:40 <sf-slack> <kgugala> @mithro the tile concept sounds interesting

19:37 <elms> litghost: have you run into eblif .param statements with don't x (unknown/don't care)?

19:38 <litghost> Yes, had to modify setundef to set parameters

19:39 <elms> ahh thanks

19:50 <litghost> https://github.com/SymbiFlow/symbiflow-arch-defs/blob/master/xc7/yosys/synth.tcl#L16

19:50 <tpb> Title: symbiflow-arch-defs/synth.tcl at master · SymbiFlow/symbiflow-arch-defs · GitHub (at github.com)

20:34 <litghost> acomodi: There is a bug now after https://github.com/SymbiFlow/vtr-verilog-to-routing/pull/9/commits/9c69b83408714340a0b3bd1b6cc2b9187ca02c73 , testing with non-multiple of 4 carry chains

20:34 <tpb> Title: [WIP] round robin packing by kgugala · Pull Request #9 · SymbiFlow/vtr-verilog-to-routing · GitHub (at github.com)

20:34 <litghost> acomodi: And there is something about https://github.com/SymbiFlow/vtr-verilog-to-routing/pull/9 that breaks the DRAM packing patterns for both murax and picosoc

20:34 <tpb> Title: [WIP] round robin packing by kgugala · Pull Request #9 · SymbiFlow/vtr-verilog-to-routing · GitHub (at github.com)

20:42 <sf-slack> <acomodi> litghost: Yes, I have been seeing the DRAM error, I have an idea on how to solve it. And probably I didn't notice the non-multiple of 4 issue, I will test and solve it tomorrow. Could you open a ticket to keep track of the issue?

20:44 <litghost> https://github.com/SymbiFlow/vtr-verilog-to-routing/issues/10

20:44 <tpb> Title: Round robin packing PR segfaults on chains that are no multiple of molecule · Issue #10 · SymbiFlow/vtr-verilog-to-routing · GitHub (at github.com)

20:46 <sf-slack> <acomodi> Great, thanks