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4250 commits 97 branches 53 tags 41 MiB
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21 commits

Author SHA1 Message Date
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
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
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 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 649bb9374f Add "opt_expr -fine" feature to remove neutral bits from reduce and logic operators 2017-07-26 18:28:55 +02:00
Clifford Wolf 0a02cdb93b Fix and_or_buffer optimization in opt_expr for signed operators 2017-07-01 16:05:26 +02:00
Larry Doolittle 2021ddecb3 Squelch trailing whitespace 2017-04-12 15:11:09 +02:00
Clifford Wolf 95dae6d416 Fixed some "used uninitialized" warnings in opt_expr 2017-02-11 10:50:48 +01:00
Clifford Wolf a5bfeb9e07 Add optimization of (a && 1'b1) and (a || 1'b0) 2017-02-11 10:05:00 +01:00
C-Elegans 94b272077d Fix issue #306, "Bug in opt -full" 
Add check for whether the high bit in the constant expression is greater
than the width of the variable, and optimizes that to a constant 1 or
0
 2017-02-10 10:38:02 -05:00
Clifford Wolf ffbe8d41f3 Fix indenting and log messages in code merged from opt_compare_pr 2017-01-31 16:20:56 +01:00
C-Elegans a94c3694d7 Refactor and generalize the comparision optimization 
Generalizes the optimization to:
a < C,
a >= C,
C > a,
C <= a
 2017-01-30 17:52:16 -05:00
C-Elegans 2fa0fd4a37 Do not use b.as_int() in calculation of bit set 2017-01-21 12:58:26 -05:00
C-Elegans 84f9cd0025 Optimize compares to powers of 2 
Remove opt_compare and put comparison pass in opt_expr

assuming a [7:0] is unsigned
a >= (1<<x) becomes |a[7:x]
a <  (1<<x) becomes !a[7:x]

Additionally:
a >= 0 becomes constant true,
a < 0 becomes constant false

delete opt_compare.cc
revert opt.cc to commit b7cfb7dbd (remove opt_compare step)
 2017-01-16 13:45:50 -05:00
Clifford Wolf 11f7b8a2a1 Added opt_expr support for div/mod by power-of-two 2016-05-29 12:17:36 +02:00
Clifford Wolf 0bc95f1e04 Added "yosys -D" feature 2016-04-21 23:28:37 +02:00
Clifford Wolf f38ca3e18f Improvements in opt_expr 2016-04-21 14:23:04 +02:00
Clifford Wolf e2f6d61c00 Typo fixes in opt_expr and opt_merge 2016-03-31 09:56:56 +02:00
Clifford Wolf 1d0f0d668a Renamed opt_const to opt_expr 2016-03-31 08:46:56 +02:00
Renamed from passes/opt/opt_const.cc (Browse further)