This was obtained by running the following SED command in passes/opt/
and then using "meld foo.cc foo.cc.orig" to manually fix all resulting
compiler errors.
sed -i.orig -r 's/"\\\\([a-zA-Z0-9_]+)"/ID(\1)/g; s/"(\$[a-zA-Z0-9_]+)"/ID(\1)/g;' *.cc
Signed-off-by: Clifford Wolf <clifford@clifford.at>
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.
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.
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.
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)
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)