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Rename dffmuxext -> dffmux, also remove constants in dff+mux

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This commit is contained in:
Eddie Hung 2019-09-11 00:56:38 -07:00
parent 3a8582081e
commit edf90afd20
4 changed files with 91 additions and 57 deletions
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2
passes/pmgen/Makefile.inc
View file

@ -27,7 +27,7 @@ $(eval $(call add_extra_objs,passes/pmgen/peepopt_pm.h))
PEEPOPT_PATTERN = passes/pmgen/peepopt_shiftmul.pmg
PEEPOPT_PATTERN += passes/pmgen/peepopt_muldiv.pmg
PEEPOPT_PATTERN += passes/pmgen/peepopt_dffmuxext.pmg
PEEPOPT_PATTERN += passes/pmgen/peepopt_dffmux.pmg
passes/pmgen/peepopt_pm.h: passes/pmgen/pmgen.py $(PEEPOPT_PATTERN)
$(P) mkdir -p passes/pmgen && python3 $< -o $@ -p peepopt $(filter-out $<,$^)

2
passes/pmgen/peepopt.cc
View file

@ -60,7 +60,7 @@ struct PeepoptPass : public Pass {
peepopt_pm pm(module, module->selected_cells());
pm.run_shiftmul();
pm.run_muldiv();
pm.run_dffmuxext();
pm.run_dffmux();
}
}
}

89
passes/pmgen/peepopt_dffmux.pmg Normal file
View file

@ -0,0 +1,89 @@
pattern dffmux
state <IdString> muxAB
match dff
select dff->type == $dff
select GetSize(port(dff, \D)) > 1
endmatch
match mux
select mux->type == $mux
select GetSize(port(mux, \Y)) > 1
choice <IdString> AB {\A, \B}
//select port(mux, AB)[GetSize(port(mux, \Y))-1].wire
index <SigSpec> port(mux, \Y) === port(dff, \D)
define <IdString> BA (AB == \A ? \B : \A)
index <SigSpec> port(mux, BA) === port(dff, \Q)
set muxAB AB
endmatch
code
SigSpec &D = mux->connections_.at(muxAB);
SigSpec &Q = dff->connections_.at(\Q);
int width = GetSize(D);
SigSpec AB = port(mux, muxAB);
if (AB[width-1] == AB[width-2]) {
did_something = true;
SigBit sign = D[width-1];
bool is_signed = sign.wire;
int i;
for (i = width-1; i >= 2; i--) {
if (!is_signed) {
module->connect(Q[i], sign);
if (D[i-1] != sign)
break;
}
else {
module->connect(Q[i], Q[i-1]);
if (D[i-2] != sign)
break;
}
}
mux->connections_.at(\A).remove(i, width-i);
mux->connections_.at(\B).remove(i, width-i);
mux->connections_.at(\Y).remove(i, width-i);
mux->fixup_parameters();
dff->connections_.at(\D).remove(i, width-i);
dff->connections_.at(\Q).remove(i, width-i);
dff->fixup_parameters();
log("dffmux pattern in %s: dff=%s, mux=%s; removed top %d bits.\n", log_id(module), log_id(dff), log_id(mux), width-i);
accept;
}
else {
int count = 0;
for (int i = width-1; i >= 0; i--) {
if (AB[i].wire)
continue;
Wire *w = Q[i].wire;
auto it = w->attributes.find(\init);
State init;
if (it != w->attributes.end())
init = it->second[Q[i].offset];
else
init = State::Sx;
if (init == State::Sx || init == AB[i].data) {
count++;
module->connect(Q[i], AB[i]);
mux->connections_.at(\A).remove(i);
mux->connections_.at(\B).remove(i);
mux->connections_.at(\Y).remove(i);
dff->connections_.at(\D).remove(i);
dff->connections_.at(\Q).remove(i);
}
}
if (count > 0) {
did_something = true;
mux->fixup_parameters();
dff->fixup_parameters();
}
log("dffmux pattern in %s: dff=%s, mux=%s; removed %d constant bits.\n", log_id(module), log_id(dff), log_id(mux), count);
accept;
}
endcode

55
passes/pmgen/peepopt_dffmuxext.pmg
View file

@ -1,55 +0,0 @@
pattern dffmuxext
state <IdString> muxAB
match dff
select dff->type == $dff
select GetSize(port(dff, \D)) > 1
endmatch
match mux
select mux->type == $mux
select GetSize(port(mux, \Y)) > 1
choice <IdString> AB {\A, \B}
//select port(mux, AB)[GetSize(port(mux, \Y))-1].wire
index <SigSpec> port(mux, \Y) === port(dff, \D)
define <IdString> BA (AB == \A ? \B : \A)
index <SigSpec> port(mux, BA) === port(dff, \Q)
filter port(mux, AB)[GetSize(port(mux, \Y))-1] == port(mux, AB)[GetSize(port(mux, \Y))-2]
set muxAB AB
endmatch
code
did_something = true;
SigSpec &D = mux->connections_.at(muxAB);
SigSpec &Q = dff->connections_.at(\Q);
int width = GetSize(D);
SigBit sign = D[width-1];
bool is_signed = sign.wire;
int i;
for (i = width-1; i >= 2; i--) {
if (!is_signed) {
module->connect(Q[i], sign);
if (D[i-1] != sign)
break;
}
else {
module->connect(Q[i], Q[i-1]);
if (D[i-2] != sign)
break;
}
}
mux->connections_.at(\A).remove(i, width-i);
mux->connections_.at(\B).remove(i, width-i);
mux->connections_.at(\Y).remove(i, width-i);
mux->fixup_parameters();
dff->connections_.at(\D).remove(i, width-i);
dff->connections_.at(\Q).remove(i, width-i);
dff->fixup_parameters();
log("dffmuxext pattern in %s: dff=%s, mux=%s; removed top %d bits.\n", log_id(module), log_id(dff), log_id(mux), width-i);
accept;
endcode