Commit Graph

306 Commits

Author SHA1 Message Date
Clifford Wolf f806b95ed6 Improve handling of and-with-1 and or-with-0 in opt_expr, fixes #327
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2019-03-14 20:52:00 +01:00
Clifford Wolf e847690bda Fix multiple issues in wreduce FF handling, fixes #835
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2019-02-28 17:24:46 -08:00
Clifford Wolf cd722f26a5 Cleanups in ARST handling in wreduce
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2019-02-24 20:34:23 +01:00
Keith Rothman 25680f6a07 Fix WREDUCE on FF not fixing ARST_VALUE parameter.
Adds test case that fails without code change.

Signed-off-by: Keith Rothman <537074+litghost@users.noreply.github.com>
2019-02-22 10:30:42 -08:00
Clifford Wolf 0e371109b0
Merge pull request #818 from YosysHQ/clifford/dffsrfix
Fix opt_rmdff handling of $_DFFSR_???_ and $_DLATCHSR_???_, fixes #816
2019-02-21 18:58:44 +01:00
Clifford Wolf 2da4c9c8f0 Fix opt_rmdff handling of $_DFFSR_???_ and $_DLATCHSR_???_, fixes #816
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2019-02-21 13:49:45 +01:00
Clifford Wolf 246391200e Add FF support to wreduce
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2019-02-20 16:36:42 +01:00
Clifford Wolf 8a63fc51d3 Bugfix in $memrd sharing
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2019-01-07 10:04:47 +01:00
Clifford Wolf d98fe8ce1f
Merge pull request #775 from whitequark/opt_flowmap
flowmap: new techmap pass
2019-01-03 17:03:18 +01:00
whitequark 07af772a72 flowmap: new techmap pass. 2019-01-03 14:28:19 +00:00
Clifford Wolf 0fc6e2bfcf
Merge pull request #770 from whitequark/opt_expr_cmp
opt_expr: refactor and improve simplification of comparisons
2019-01-02 17:34:04 +01:00
whitequark bf8db55ef3 opt_expr: improve simplification of comparisons with large constants.
The idea behind this simplification is that a N-bit signal X being
compared with an M-bit constant where M>N and the constant has Nth
or higher bit set, it either always succeeds or always fails.

However, the existing implementation only worked with one-hot signals
for some reason. It also printed incorrect messages.

This commit adjusts the simplification to have as much power as
possible, and fixes other bugs.
2019-01-02 15:45:28 +00:00
Clifford Wolf 2e606b1802
Merge pull request #773 from whitequark/opt_lut_elim_fixes
opt_lut: elimination fixes
2019-01-02 15:45:29 +01:00
whitequark efa278e232 Fix typographical and grammatical errors and inconsistencies.
The initial list of hits was generated with the codespell command
below, and each hit was evaluated and fixed manually while taking
context into consideration.

    DIRS="kernel/ frontends/ backends/ passes/ techlibs/"
    DIRS="${DIRS} libs/ezsat/ libs/subcircuit"
    codespell $DIRS -S *.o -L upto,iff,thru,synopsys,uint

More hits were found by looking through comments and strings manually.
2019-01-02 13:12:17 +00:00
whitequark c55dfb8369 opt_lut: reflect changes in sigmap.
Otherwise, some LUTs will be missed during elimination.
2019-01-02 10:21:58 +00:00
whitequark 06143ab33f opt_lut: use a worklist, and revisit cells affected by elimination. 2019-01-02 09:36:32 +00:00
whitequark f7363ac508 opt_lut: count eliminated cells, and set opt.did_something for them. 2019-01-02 09:14:43 +00:00
whitequark 4fd458290c opt_expr: refactor simplification of unsigned X<onehot and X>=onehot. NFCI. 2019-01-02 05:11:29 +00:00
whitequark 9e9846a6ea opt_expr: refactor simplification of signed X>=0 and X<0. NFCI. 2019-01-02 03:01:25 +00:00
whitequark 8e53d2e0bf opt_expr: simplify any unsigned comparisons with all-0 and all-1.
Before this commit, only unsigned comparisons with all-0 would be
simplified. This commit also makes the code handling such comparisons
to be more rigorous and not abort on unexpected input.
2019-01-02 02:45:49 +00:00
whitequark 42c356c49c opt_lut: eliminate LUTs evaluating to constants or inputs. 2018-12-31 23:55:40 +00:00
Clifford Wolf 0a840dd883 Fix handling of (* keep *) wires in wreduce
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2018-12-31 16:37:40 +01:00
Clifford Wolf 556341a77f
Merge pull request #720 from whitequark/master
lut2mux: handle 1-bit INIT constant in $lut cells
2018-12-16 15:27:23 +01:00
whitequark 7ec740b7ad opt_lut: leave intact LUTs with cascade feeding module outputs. 2018-12-07 17:13:52 +00:00
whitequark 9eb03d458d opt_lut: show original truth table for both cells. 2018-12-07 17:04:41 +00:00
whitequark a8ab722824 opt_lut: add -limit option, for debugging misoptimizations. 2018-12-07 16:36:26 +00:00
Clifford Wolf 643f858acf Bugfix in opt_expr handling of a<0 and a>=0
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2018-12-06 07:29:21 +01:00
whitequark 88217d0157 opt_lut: simplify type conversion. NFC. 2018-12-05 19:12:02 +00:00
Clifford Wolf 2d98db73e3 Rename opt_lut.cpp to opt_lut.cc
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2018-12-05 18:03:58 +01:00
whitequark 45cb6200af opt_lut: add -dlogic, to avoid disturbing logic such as carry chains. 2018-12-05 16:30:37 +00:00
whitequark e603484070 opt_lut: always prefer to eliminate 1-LUTs.
These are always either buffers or inverters, and keeping the larger
LUT preserves more source-level information about the design.
2018-12-05 16:30:37 +00:00
whitequark 59eea0183f opt_lut: collect and display statistics. 2018-12-05 16:30:37 +00:00
whitequark e54c7e951c opt_lut: refactor to use a worker. NFC. 2018-12-05 16:30:37 +00:00
whitequark 9e072ec21f opt_lut: new pass, to combine LUTs for tighter packing. 2018-12-05 16:30:37 +00:00
Clifford Wolf ab97eddee9 Add iteration limit to "opt_muxtree"
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2018-11-20 17:56:47 +01:00
Henner Zeller 3aa4484a3c Consistent use of 'override' for virtual methods in derived classes.
o Not all derived methods were marked 'override', but it is a great
  feature of C++11 that we should make use of.
o While at it: touched header files got a -*- c++ -*- for emacs to
  provide support for that language.
o use YS_OVERRIDE for all override keywords (though we should probably
  use the plain keyword going forward now that C++11 is established)
2018-07-20 23:51:06 -07:00
Clifford Wolf 587056447e Add optimization of tristate buffer with constant control input
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2018-05-12 15:18:27 +02:00
Clifford Wolf fba499b866 Fix opt_rmdff handling of $dlatchsr
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2018-02-26 11:46:05 +01:00
Clifford Wolf eb67a7532b Add $allconst and $allseq cell types
Signed-off-by: Clifford Wolf <clifford@clifford.at>
2018-02-23 13:14:47 +01:00
Clifford Wolf ca2adc30c9 Add warnings for driver-driver conflicts between FFs (and other cells) and constants 2017-12-12 17:13:27 +01:00
Clifford Wolf c238f45ecf Fix memory corruption bug in opt_rmdff 2017-10-26 18:02:15 +02:00
Clifford Wolf 1e502ef5a0 Fix typo in opt_clean log message 2017-10-26 18:01:48 +02:00
Clifford Wolf 716dbc9274 Revert 90be0d8 as it causes endless loops for some designs 2017-10-14 11:57:25 +02:00
Kaj Tuomi 90be0d800b Fix input vector for reduce cells. 2017-10-12 13:05:10 +03:00
Andrew Zonenberg 66e8986ae7 Minor changes to opt_demorgan requested during code review 2017-09-14 10:35:25 -07:00
Andrew Zonenberg 6da5d36968 Initial version of opt_demorgan is functioning for AND/OR gates. Not the prettiest results for bus inputs, but this can be improved 2017-09-12 18:47:46 -07:00
Clifford Wolf 68c42f3a19 Don't track , ... contradictions through x/z-bits 2017-08-25 16:18:17 +02:00
Clifford Wolf db6d78a186 Add removing of redundant pairs of bits in ==, ===, !=, and !== to opt_expr 2017-08-25 16:02:15 +02:00
Clifford Wolf 88983f5012 Mostly coding style related fixes in rmports pass 2017-08-15 11:32:35 +02:00
Andrew Zonenberg 15e41d6363 rmports: Now remove ports from cell instances if we optimized them out of that cell 2017-08-14 11:44:05 -07:00