=======================================================
+Yosys 0.8 .. Yosys 0.8-dev
+--------------------------
+
+ * Various
+ - Added $changed support to read_verilog
+ - Added "write_edif -attrprop"
+ - Added "ice40_unlut" pass
+ - Added "opt_lut" pass
+ - Added "synth_ice40 -relut"
+ - Added "synth_ice40 -noabc"
+ - Added "gate2lut.v" techmap rule
+ - Added "rename -src"
+ - Added "equiv_opt" pass
+ - Added "read_aiger" frontend
+ - "synth_xilinx" to now infer hard shift registers, using new "shregmap -tech xilinx"
+
+
+Yosys 0.7 .. Yosys 0.8
+----------------------
+
+ * Various
+ - Many bugfixes and small improvements
+ - Strip debug symbols from installed binary
+ - Replace -ignore_redef with -[no]overwrite in front-ends
+ - Added write_verilog hex dump support, add -nohex option
+ - Added "write_verilog -decimal"
+ - Added "scc -set_attr"
+ - Added "verilog_defines" command
+ - Remeber defines from one read_verilog to next
+ - Added support for hierarchical defparam
+ - Added FIRRTL back-end
+ - Improved ABC default scripts
+ - Added "design -reset-vlog"
+ - Added "yosys -W regex", "yosys -w regex", and "yosys -e regex"
+ - Added Verilog $rtoi and $itor support
+ - Added "check -initdrv"
+ - Added "read_blif -wideports"
+ - Added support for systemVerilog "++" and "--" operators
+ - Added support for SystemVerilog unique, unique0, and priority case
+ - Added "write_edif" options for edif "flavors"
+ - Added support for resetall compiler directive
+ - Added simple C beck-end (bitwise combinatorical only atm)
+ - Added $_ANDNOT_ and $_ORNOT_ cell types
+ - Added cell library aliases to "abc -g"
+ - Added "setundef -anyseq"
+ - Added "chtype" command
+ - Added "design -import"
+ - Added "write_table" command
+ - Added "read_json" command
+ - Added "sim" command
+ - Added "extract_fa" and "extract_reduce" commands
+ - Added "extract_counter" command
+ - Added "opt_demorgan" command
+ - Added support for $size and $bits SystemVerilog functions
+ - Added "blackbox" command
+ - Added "ltp" command
+ - Added support for editline as replacement for readline
+ - Added warnings for driver-driver conflicts between FFs (and other cells) and constants
+ - Added "yosys -E" for creating Makefile dependencies files
+ - Added "synth -noshare"
+ - Added "memory_nordff"
+ - Added "setundef -undef -expose -anyconst"
+ - Added "expose -input"
+ - Added specify/specparam parser support (simply ignore them)
+ - Added "write_blif -inames -iattr"
+ - Added "hierarchy -simcheck"
+ - Added an option to statically link abc into yosys
+ - Added protobuf back-end
+ - Added BLIF parsing support for .conn and .cname
+ - Added read_verilog error checking for reg/wire/logic misuse
+ - Added "make coverage" and ENABLE_GCOV build option
+
+ * Changes in Yosys APIs
+ - Added ConstEval defaultval feature
+ - Added {get,set}_src_attribute() methods on RTLIL::AttrObject
+ - Added SigSpec::is_fully_ones() and Const::is_fully_ones()
+ - Added log_file_warning() and log_file_error() functions
+
+ * Formal Verification
+ - Added "write_aiger"
+ - Added "yosys-smtbmc --aig"
+ - Added "always <positive_int>" to .smtc format
+ - Added $cover cell type and support for cover properties
+ - Added $fair/$live cell type and support for liveness properties
+ - Added smtbmc support for memory vcd dumping
+ - Added "chformal" command
+ - Added "write_smt2 -stbv" and "write_smt2 -stdt"
+ - Fix equiv_simple, old behavior now available with "equiv_simple -short"
+ - Change to Yices2 as default SMT solver (it is GPL now)
+ - Added "yosys-smtbmc --presat" (now default in SymbiYosys)
+ - Added "yosys-smtbmc --smtc-init --smtc-top --noinit"
+ - Added a brand new "write_btor" command for BTOR2
+ - Added clk2fflogic memory support and other improvements
+ - Added "async memory write" support to write_smt2
+ - Simulate clock toggling in yosys-smtbmc VCD output
+ - Added $allseq/$allconst cells for EA-solving
+ - Make -nordff the default in "prep"
+ - Added (* gclk *) attribute
+ - Added "async2sync" pass for single-clock designs with async resets
+
+ * Verific support
+ - Many improvements in Verific front-end
+ - Added proper handling of concurent SVA properties
+ - Map "const" and "rand const" to $anyseq/$anyconst
+ - Added "verific -import -flatten" and "verific -import -extnets"
+ - Added "verific -vlog-incdir -vlog-define -vlog-libdir"
+ - Remove PSL support (because PSL has been removed in upstream Verific)
+ - Improve integration with "hierarchy" command design elaboration
+ - Added YOSYS_NOVERIFIC for running non-verific test cases with verific bin
+ - Added simpilied "read" command that automatically uses verific if available
+ - Added "verific -set-<severity> <msg_id>.."
+ - Added "verific -work <libname>"
+
+ * New back-ends
+ - Added initial Coolrunner-II support
+ - Added initial eASIC support
+ - Added initial ECP5 support
+
+ * GreenPAK Support
+ - Added support for GP_DLATCH, GP_SPI, GP_DCMx, GP_COUNTx, etc.
+
+ * iCE40 Support
+ - Add "synth_ice40 -vpr"
+ - Add "synth_ice40 -nodffe"
+ - Add "synth_ice40 -json"
+ - Add Support for UltraPlus cells
+
+ * MAX10 and Cyclone IV Support
+ - Added initial version of metacommand "synth_intel".
+ - Improved write_verilog command to produce VQM netlist for Quartus Prime.
+ - Added support for MAX10 FPGA family synthesis.
+ - Added support for Cyclone IV family synthesis.
+ - Added example of implementation for DE2i-150 board.
+ - Added example of implementation for MAX10 development kit.
+ - Added LFSR example from Asic World.
+ - Added "dffinit -highlow" for mapping to Intel primitives
+
+
+Yosys 0.6 .. Yosys 0.7
+----------------------
+
+ * Various
+ - Added "yosys -D" feature
+ - Added support for installed plugins in $(DATDIR)/plugins/
+ - Renamed opt_const to opt_expr
+ - Renamed opt_share to opt_merge
+ - Added "prep -flatten" and "synth -flatten"
+ - Added "prep -auto-top" and "synth -auto-top"
+ - Using "mfs" and "lutpack" in ABC lut mapping
+ - Support for abstract modules in chparam
+ - Cleanup abstract modules at end of "hierarchy -top"
+ - Added tristate buffer support to iopadmap
+ - Added opt_expr support for div/mod by power-of-two
+ - Added "select -assert-min <N> -assert-max <N>"
+ - Added "attrmvcp" pass
+ - Added "attrmap" command
+ - Added "tee +INT -INT"
+ - Added "zinit" pass
+ - Added "setparam -type"
+ - Added "shregmap" pass
+ - Added "setundef -init"
+ - Added "nlutmap -assert"
+ - Added $sop cell type and "abc -sop -I <num> -P <num>"
+ - Added "dc2" to default ABC scripts
+ - Added "deminout"
+ - Added "insbuf" command
+ - Added "prep -nomem"
+ - Added "opt_rmdff -keepdc"
+ - Added "prep -nokeepdc"
+ - Added initial version of "synth_gowin"
+ - Added "fsm_expand -full"
+ - Added support for fsm_encoding="user"
+ - Many improvements in GreenPAK4 support
+ - Added black box modules for all Xilinx 7-series lib cells
+ - Added synth_ice40 support for latches via logic loops
+ - Fixed ice40_opt lut unmapping, added "ice40_opt -unlut"
+
+ * Build System
+ - Added ABCEXTERNAL and ABCURL make variables
+ - Added BINDIR, LIBDIR, and DATDIR make variables
+ - Added PKG_CONFIG make variable
+ - Added SEED make variable (for "make test")
+ - Added YOSYS_VER_STR make variable
+ - Updated min GCC requirement to GCC 4.8
+ - Updated required Bison version to Bison 3.x
+
+ * Internal APIs
+ - Added ast.h to exported headers
+ - Added ScriptPass helper class for script-like passes
+ - Added CellEdgesDatabase API
+
+ * Front-ends and Back-ends
+ - Added filename glob support to all front-ends
+ - Added avail (black-box) module params to ilang format
+ - Added $display %m support
+ - Added support for $stop Verilog system task
+ - Added support for SystemVerilog packages
+ - Fixed procedural assignments to non-unique lvalues, e.g. {y,y} = {a,b}
+ - Added support for "active high" and "active low" latches in read_blif and write_blif
+ - Use init value "2" for all uninitialized FFs in BLIF back-end
+ - Added "read_blif -sop"
+ - Added "write_blif -noalias"
+ - Added various write_blif options for VTR support
+ - write_json: also write module attributes.
+ - Added "write_verilog -nodec -nostr -defparam"
+ - Added "read_verilog -norestrict -assume-asserts"
+ - Added support for bus interfaces to "read_liberty -lib"
+ - Added liberty parser support for types within cell decls
+ - Added "write_verilog -renameprefix -v"
+ - Added "write_edif -nogndvcc"
+
+ * Formal Verification
+ - Support for hierarchical designs in smt2 back-end
+ - Yosys-smtbmc: Support for hierarchical VCD dumping
+ - Added $initstate cell type and vlog function
+ - Added $anyconst and $anyseq cell types and vlog functions
+ - Added printing of code loc of failed asserts to yosys-smtbmc
+ - Added memory_memx pass, "memory -memx", and "prep -memx"
+ - Added "proc_mux -ifx"
+ - Added "yosys-smtbmc -g"
+ - Deprecated "write_smt2 -regs" (by default on now)
+ - Made "write_smt2 -bv -mem" default, added "write_smt2 -nobv -nomem"
+ - Added support for memories to smtio.py
+ - Added "yosys-smtbmc --dump-vlogtb"
+ - Added "yosys-smtbmc --smtc --dump-smtc"
+ - Added "yosys-smtbmc --dump-all"
+ - Added assertpmux command
+ - Added "yosys-smtbmc --unroll"
+ - Added $past, $stable, $rose, $fell SVA functions
+ - Added "yosys-smtbmc --noinfo and --dummy"
+ - Added "yosys-smtbmc --noincr"
+ - Added "yosys-smtbmc --cex <filename>"
+ - Added $ff and $_FF_ cell types
+ - Added $global_clock verilog syntax support for creating $ff cells
+ - Added clk2fflogic
+
+
+Yosys 0.5 .. Yosys 0.6
+----------------------
+
+ * Various
+ - Added Contributor Covenant Code of Conduct
+ - Various improvements in dict<> and pool<>
+ - Added hashlib::mfp and refactored SigMap
+ - Improved support for reals as module parameters
+ - Various improvements in SMT2 back-end
+ - Added "keep_hierarchy" attribute
+ - Verilog front-end: define `BLACKBOX in -lib mode
+ - Added API for converting internal cells to AIGs
+ - Added ENABLE_LIBYOSYS Makefile option
+ - Removed "techmap -share_map" (use "-map +/filename" instead)
+ - Switched all Python scripts to Python 3
+ - Added support for $display()/$write() and $finish() to Verilog front-end
+ - Added "yosys-smtbmc" formal verification flow
+ - Added options for clang sanitizers to Makefile
+
+ * New commands and options
+ - Added "scc -expect <N> -nofeedback"
+ - Added "proc_dlatch"
+ - Added "check"
+ - Added "select %xe %cie %coe %M %C %R"
+ - Added "sat -dump_json" (WaveJSON format)
+ - Added "sat -tempinduct-baseonly -tempinduct-inductonly"
+ - Added "sat -stepsize" and "sat -tempinduct-step"
+ - Added "sat -show-regs -show-public -show-all"
+ - Added "write_json" (Native Yosys JSON format)
+ - Added "write_blif -attr"
+ - Added "dffinit"
+ - Added "chparam"
+ - Added "muxcover"
+ - Added "pmuxtree"
+ - Added memory_bram "make_outreg" feature
+ - Added "splice -wires"
+ - Added "dff2dffe -direct-match"
+ - Added simplemap $lut support
+ - Added "read_blif"
+ - Added "opt_share -share_all"
+ - Added "aigmap"
+ - Added "write_smt2 -mem -regs -wires"
+ - Added "memory -nordff"
+ - Added "write_smv"
+ - Added "synth -nordff -noalumacc"
+ - Added "rename -top new_name"
+ - Added "opt_const -clkinv"
+ - Added "synth -nofsm"
+ - Added "miter -assert"
+ - Added "read_verilog -noautowire"
+ - Added "read_verilog -nodpi"
+ - Added "tribuf"
+ - Added "lut2mux"
+ - Added "nlutmap"
+ - Added "qwp"
+ - Added "test_cell -noeval"
+ - Added "edgetypes"
+ - Added "equiv_struct"
+ - Added "equiv_purge"
+ - Added "equiv_mark"
+ - Added "equiv_add -try -cell"
+ - Added "singleton"
+ - Added "abc -g -luts"
+ - Added "torder"
+ - Added "write_blif -cname"
+ - Added "submod -copy"
+ - Added "dffsr2dff"
+ - Added "stat -liberty"
+
+ * Synthesis metacommands
+ - Various improvements in synth_xilinx
+ - Added synth_ice40 and synth_greenpak4
+ - Added "prep" metacommand for "synthesis lite"
+
+ * Cell library changes
+ - Added cell types to "help" system
+ - Added $meminit cell type
+ - Added $assume cell type
+ - Added $_MUX4_, $_MUX8_, and $_MUX16_ cells
+ - Added $tribuf and $_TBUF_ cell types
+ - Added read-enable to memory model
+
+ * YosysJS
+ - Various improvements in emscripten build
+ - Added alternative webworker-based JS API
+ - Added a few example applications
+
+
Yosys 0.4 .. Yosys 0.5
----------------------
* Changes for simple synthesis flows
- There is now a "synth" command with a recommended default script
- Many improvements in synthesis of arithmetic functions to gates
- - Multiplieres and adders with many operands are using carry-save adder trees
+ - Multipliers and adders with many operands are using carry-save adder trees
- Remaining adders are now implemented using Brent-Kung carry look-ahead adders
- Various new high-level optimizations on RTL netlist
- Various improvements in FSM optimization
- Added macros for code coverage counters
- Added some Makefile magic for pretty make logs
- Added "kernel/yosys.h" with all the core definitions
- - Chanded a lot of code from FILE* to c++ streams
+ - Changed a lot of code from FILE* to c++ streams
- Added RTLIL::Monitor API and "trace" command
- Added "Yosys" C++ namespace
- Added "sat -dump_cnf" feature
- Added "sat -initsteps <N>" feature
- Added "freduce -stop <N>" feature
- - Added "fredure -dump <prefix>" feature
+ - Added "freduce -dump <prefix>" feature
* Integration with ABC:
- Updated ABC rev to 7600ffb9340c
- Added "expose" command
- Added support for @<sel_name> to sat and eval signal expressions
- * Changes in the 'make test' framework and auxilary test tools:
+ * Changes in the 'make test' framework and auxiliary test tools:
- Added autotest.sh -p and -f options
- Replaced autotest.sh ISIM support with XSIM support
- Added test cases for SAT framework
* Added "abbreviated IDs":
- - Now $<something>$foo can be abbriviated as $foo.
+ - Now $<something>$foo can be abbreviated as $foo.
- Usually this last part is a unique id (from RTLIL::autoidx)
- This abbreviated IDs are now also used in "show" output