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peepopt: Remove now-redundant dffmux pattern.

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This commit is contained in:
Marcelina Kościelnicka 2020-07-15 02:37:43 +02:00
parent acd8c5c205
commit a0e99a9f3f
5 changed files with 129 additions and 318 deletions
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1
passes/pmgen/Makefile.inc
View file

@ -36,7 +36,6 @@ $(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_dffmux.pmg
passes/pmgen/peepopt_pm.h: passes/pmgen/pmgen.py $(PEEPOPT_PATTERN)
$(P) mkdir -p passes/pmgen && $(PYTHON_EXECUTABLE) $< -o $@ -p peepopt $(filter-out $<,$^)

3
passes/pmgen/peepopt.cc
View file

@ -67,8 +67,6 @@ struct PeepoptPass : public Pass {
GENERATE_PATTERN(peepopt_pm, shiftmul);
else if (genmode == "muldiv")
GENERATE_PATTERN(peepopt_pm, muldiv);
else if (genmode == "dffmux")
GENERATE_PATTERN(peepopt_pm, dffmux);
else
log_abort();
return;
@ -106,7 +104,6 @@ struct PeepoptPass : public Pass {
pm.run_shiftmul();
pm.run_muldiv();
pm.run_dffmux();
for (auto w : module->wires()) {
auto it = w->attributes.find(ID::init);

171
passes/pmgen/peepopt_dffmux.pmg
View file

@ -1,171 +0,0 @@
pattern dffmux
state <IdString> cemuxAB rstmuxBA
state <SigSpec> sigD
match dff
select dff->type == $dff
select GetSize(port(dff, \D)) > 1
endmatch
code sigD
sigD = port(dff, \D);
endcode
match rstmux
select rstmux->type == $mux
select GetSize(port(rstmux, \Y)) > 1
index <SigSpec> port(rstmux, \Y) === sigD
choice <IdString> BA {\B, \A}
select port(rstmux, BA).is_fully_const()
set rstmuxBA BA
semioptional
endmatch
code sigD
if (rstmux)
sigD = port(rstmux, rstmuxBA == \B ? \A : \B);
endcode
match cemux
select cemux->type == $mux
select GetSize(port(cemux, \Y)) > 1
index <SigSpec> port(cemux, \Y) === sigD
choice <IdString> AB {\A, \B}
index <SigSpec> port(cemux, AB) === port(dff, \Q)
set cemuxAB AB
semioptional
endmatch
code
if (!cemux && !rstmux)
reject;
endcode
code
Const rst;
SigSpec D;
if (cemux) {
D = port(cemux, cemuxAB == \A ? \B : \A);
if (rstmux)
rst = port(rstmux, rstmuxBA).as_const();
else
rst = Const(State::Sx, GetSize(D));
}
else {
log_assert(rstmux);
D = port(rstmux, rstmuxBA == \B ? \A : \B);
rst = port(rstmux, rstmuxBA).as_const();
}
SigSpec Q = port(dff, \Q);
int width = GetSize(D);
SigSpec dffD = dff->getPort(\D);
SigSpec dffQ = dff->getPort(\Q);
Const initval;
for (auto b : Q) {
auto it = initbits.find(b);
initval.bits.push_back(it == initbits.end() ? State::Sx : it->second);
}
auto cmpx = [=](State lhs, State rhs) {
if (lhs == State::Sx || rhs == State::Sx)
return true;
return lhs == rhs;
};
int i = width-1;
while (i > 1) {
if (D[i] != D[i-1])
break;
if (!cmpx(rst[i], rst[i-1]))
break;
if (!cmpx(initval[i], initval[i-1]))
break;
if (!cmpx(rst[i], initval[i]))
break;
rminitbits.insert(Q[i]);
module->connect(Q[i], Q[i-1]);
i--;
}
if (i < width-1) {
did_something = true;
if (cemux) {
SigSpec ceA = cemux->getPort(\A);
SigSpec ceB = cemux->getPort(\B);
SigSpec ceY = cemux->getPort(\Y);
ceA.remove(i, width-1-i);
ceB.remove(i, width-1-i);
ceY.remove(i, width-1-i);
cemux->setPort(\A, ceA);
cemux->setPort(\B, ceB);
cemux->setPort(\Y, ceY);
cemux->fixup_parameters();
blacklist(cemux);
}
if (rstmux) {
SigSpec rstA = rstmux->getPort(\A);
SigSpec rstB = rstmux->getPort(\B);
SigSpec rstY = rstmux->getPort(\Y);
rstA.remove(i, width-1-i);
rstB.remove(i, width-1-i);
rstY.remove(i, width-1-i);
rstmux->setPort(\A, rstA);
rstmux->setPort(\B, rstB);
rstmux->setPort(\Y, rstY);
rstmux->fixup_parameters();
blacklist(rstmux);
}
dffD.remove(i, width-1-i);
dffQ.remove(i, width-1-i);
dff->setPort(\D, dffD);
dff->setPort(\Q, dffQ);
dff->fixup_parameters();
blacklist(dff);
log("dffcemux pattern in %s: dff=%s, cemux=%s, rstmux=%s; removed top %d bits.\n", log_id(module), log_id(dff), log_id(cemux, "n/a"), log_id(rstmux, "n/a"), width-1-i);
width = i+1;
}
if (cemux) {
SigSpec ceA = cemux->getPort(\A);
SigSpec ceB = cemux->getPort(\B);
SigSpec ceY = cemux->getPort(\Y);
int count = 0;
for (int i = width-1; i >= 0; i--) {
if (D[i].wire)
continue;
if (cmpx(rst[i], D[i].data) && cmpx(initval[i], D[i].data)) {
count++;
rminitbits.insert(Q[i]);
module->connect(Q[i], D[i]);
ceA.remove(i);
ceB.remove(i);
ceY.remove(i);
dffD.remove(i);
dffQ.remove(i);
}
}
if (count > 0)
{
did_something = true;
cemux->setPort(\A, ceA);
cemux->setPort(\B, ceB);
cemux->setPort(\Y, ceY);
cemux->fixup_parameters();
blacklist(cemux);
dff->setPort(\D, dffD);
dff->setPort(\Q, dffQ);
dff->fixup_parameters();
blacklist(dff);
log("dffcemux pattern in %s: dff=%s, cemux=%s, rstmux=%s; removed %d constant bits.\n", log_id(module), log_id(dff), log_id(cemux), log_id(rstmux, "n/a"), count);
}
}
if (did_something)
accept;
endcode