The report_incremental_reuse command
is available at any stage of the flow after read_checkpoint
-incremental has been used. The report allows the user to compare the
following between the reference and current design runs:
- Examine cell, net, I/O and pin reuse in the current run
- Runtimes
- Timing WNS at each stage of the flow
- Tool options
- Tool versions
-
iphys_opt_designreplaying optimization - QoR suggestions applied with the incremental flow
By examining the cell reuse and the other factors mentioned above, a user can determine the effectiveness of the incremental. Where the flow is judged ineffective, a user would typically update the checkpoint to a newer version of the design or adjust the tool flow. The report is split into seven sections.
Flow Summary
This reports the general information for the current whole incremental flow:
1. Incremental Flow Summary
+--------------------------+----------------+
| Flow Information | Value |
+--------------------------+----------------+
| Synthesis Flow | Default |
| Auto Incremental | No |
| Incremental Directive | TimingClosure |
| Reuse mode | High |
| Target WNS | -0.160 |
| QoR Suggestions | 0 |
+--------------------------+----------------+Reuse Summary
This contains an overview of the cells, nets, pins, and ports that are reused. An example is:
2. Reuse Summary
+------+--------------------+------------------+------------------+--------+
| Type |Matched % (of Total)|Reuse % (of Total)|Fixed % (of Total)| Total |
+------+--------------------+------------------+------------------+--------+
| Cells| 100.00 | 99.82 | 0.38 | 688982 |
| Nets | 99.98 | 99.72 | 0.00 | 795869 |
| Pins | - | 99.11 | - | 2823905|
| Ports| 100.00 | 100.00 | 100.00 | 667 |
+------+--------------------+------------------+------------------+--------+Reference Checkpoint Information
This contains information about the reference checkpoint. From this section you can examine the following:
- Vivado version that generated it
- Stage of the implementation
- Recorded WNS and WHS
- Speedfile version information of both the reference and incremental runs
An example is:
3. Reference Checkpoint Information
+----------------------------------+----------------------------+
| DCP Information | Value |
+----------------------------------+----------------------------+
| Vivado Version | 2020.2 |
| DCP State | POST_ROUTE |
| Recorded WNS | -0.305 |
| Recorded WHS | 0.000 |
| Reference Speed File Version | PRODUCTION 1.27 02-28-2020 |
| Incremental Speed File Version | PRODUCTION 1.27 02-28-2020 |
+----------------------------------+----------------------------+
* Recorded WNS/WHS timing numbers are estimated timing numbers. They may vary slightly from sign-off timing numbers.
Comparison with Reference Run
This contains useful metrics about a comparison with the reference run. From this section you can compare the following:
- Runtime information
- WNS at each stage of the flow
- Tool options at each stage of the flow.
Optimization Comparison with Reference Run
This section contains the iphys_opt_design replaying information which is retrieved from the
reference dcp, along with the RQS suggestions derived, generated, and applied in the
current incremental flow. An example is:
5.1 iphys_opt_replay Optimizations
+-------------------------+--------+------------+
| iphys_opt_design replay | Reused | Not Reused |
+-------------------------+--------+------------+
| hold_fix | 113 | 0 |
| fanout_opt | 2 | 0 |
| critical_cell_opt | 10 | 0 |
| restruct_opt | 4 | 0 |
+-------------------------+--------+------------+
5.2 QoR Suggestion Optimizations
+------------------------------------------+-------+
| QoR Suggestions | Value |
+------------------------------------------+-------+
| QoR Suggestions | 0 |
| Suggestions Included In References | 0 |
| Yet to apply | 0 |
| Applied | 0 |
| Failed to apply | 0 |
| New Suggestions | 0 |
| Yet to apply | 0 |
| Applied | 0 |
| Failed to apply | 0 |
| Non Incremental Friendly New Suggestions | 0 |
+------------------------------------------+-------+
Command Comparison with Reference Run
This section contains the commands executed for flow command comparison. An example is:
6.1 Reference:
-------------------
opt_design -directive Default
place_design -directive ExtraPostPlacementOpt
phys_opt_design -directive AlternateFlowWithRetiming
phys_opt_design -directive AggressiveFanoutOpt
phys_opt_design -directive AggressiveExplore
phys_opt_design -directive AlternateReplication
route_design -directive Explore
phys_opt_design -directive Explore6.2 Incremental:
-------------------
opt_design -directive Default
read_checkpoint -directive TimingClosure -incremental
/group/2020.1/post_route_phys_opt2.dcpNon-reuse Information
This contains metrics about what was not reused and why. The following is an example:
7. Non Reuse Information
+------------------------------------------------------+------+
| Type | % |
+------------------------------------------------------+------+
| Non-Reused Cells | 0.17 |
| Discarded illegal placement due to netlist changes | 0.17 |
| Discarded to improve timing | 0.01 |
| Partially reused nets | 0.00 |
| Non-Reused nets | 0.27 |
| Non-Reused Ports | 0.00 |
+------------------------------------------------------+------+