Comparing two SDC (Synopsys Design Constraint) files
NAME:
aid_diff_sdc diff two sdc files
SYNTAX:
command aid_diff_sdc
[-product product]
[-compile_log compilelog]
file1
file2
Data Types
product string
compilelog string
file1 string
file2 string
ARGUMENTS
-product product
Synopsys product name. Only "dcrt" and "icc2" are supported. If this option is omitted,
its value will be inferred from $synopsys_program_name. If $synopsys_program_name is also
missing, option value defaults to "dcrt".
-compile_log compilelog
Path to the compile log file. This option is designed for the "constraint preservation"
project in Descartes only. Please skip this option if you don't need it. If this option is
specified, the compile log would be considered during verification, and verify result may
be different from when this option is omitted.
file1
SDC file 1
file2
SDC file 2
This command is used to differentiate two SDC files.
SDC files are exported by the write_sdc command in DC/Descartes/ICC/ICC2 or other Synopsys products. A typical SDC file is a list of flattened SDC commands. It would only contain SDC commands like create_clock or set_input_delay, and netlist query commands like get_cells or get_pins. No logic control commands such as if, foreach, switch are expected in an SDC file.
Many SDC commands involves a collection of design objects so it can be structured as one command that constraints a large collection, or can be sturctured as several commands and each of them constraints a small collection. For example, following two SDC files are literally different but indeed have the same effect.
File 1:
group_path -name group_1 -from [get_cells {A B}] -to [get_cells {C D}]
File 2:
group_path -name group_1 -from [get_cells A] -to [get_cells C]
group_path -name group_1 -from [get_cells A] -to [get_cells D]
group_path -name group_1 -from [get_cells B] -to [get_cells C]
group_path -name group_1 -from [get_cells B] -to [get_cells D]
sdcdiff will first decompose all SDC commands in both input SDC files into atomic SDC commands, then sort the atomic commands, and finally differentiate two SDC files. An atomic SDC command is an SDC command in which all arguments that are collections have the length of one. All group_path commands as presented in File 2 in above example are atomic SDC commands.
To parse a normal SDC command and decompose it into atomic SDC commands, some information of option configuration for each SDC command is recorded along this AID command. The supported command list differs among products, and can be reviewed at lib/cmd.${p}.list, where $p can be either icc2 or dcrt.
|-- README
|-- aid_diff_sdc
| `-- aid_diff_sdc.tcl
|-- bin
| |-- comparator.py
| |-- extractor.py
| |-- getcmds
| |-- sdcdiff
| `-- sdcflat
|-- lib
| |-- cmd.dc.list
| |-- cmd.dcrt.list
| |-- cmd.icc2.list
| |-- cmdopts.dc.cfg
| |-- cmdopts.dcrt.cfg
| `-- cmdopts.icc2.cfg
`-- misc
|-- diff_st_and_mt.py
`-- getoptions.tcl
bin/comparator.py- A Python Process module to compare command pools for file 1 and file 2, and remove common commands if there are any.
bin/extractor.py- A Python Process module to extract flattened commands from SDC file into a command pool which is shared with comparator.
bin/getcmds- A tclparser script to get command statistics from SDC file. Very slow. Will be replaced by Python codes in coming version.
bin/sdcdiff- Program entrance.
bin/sdcflat- A tclparser script to flatten tcl commands in SDC file and output flattened commands in stream.
bin/aid_diff_sdc.tcl- A PV AID command implementation. A wrapper of sdcdiff.
lib/cmd.*.list- A text file of command list in synopsys products.
lib/cmdopts.*.cfg- A database in tcl syntax that definies all command configurations.
misc/diff_st_and_mt.py- Compare runtime performance of single core and multi core solutions.
misc/getoptions.tcl- Parse command configuration from command help page.