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Refactor peepopt_dffmux and be sensitive to \init when trimming

This commit is contained in:
Eddie Hung 2019-10-02 17:53:42 -07:00
parent e730a595ee
commit d99810ad8a
1 changed files with 63 additions and 32 deletions
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95
passes/pmgen/peepopt_dffmux.pmg
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@ -8,21 +8,23 @@ match 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) === port(dff, \D)
index <SigSpec> port(rstmux, \Y) === sigD
choice <IdString> BA {\B, \A}
select port(rstmux, BA).is_fully_const()
set rstmuxBA BA
optional
semioptional
endmatch
code sigD
if (rstmux)
sigD = port(rstmux, rstmuxBA == \B ? \A : \B);
else
sigD = port(dff, \D);
endcode
match cemux
@ -32,45 +34,70 @@ match cemux
choice <IdString> AB {\A, \B}
index <SigSpec> port(cemux, AB) === port(dff, \Q)
set cemuxAB AB
semioptional
endmatch
code
SigSpec D = port(cemux, cemuxAB == \A ? \B : \A);
SigSpec Q = port(dff, \Q);
if (!cemux && !rstmux)
reject;
endcode
code
Const rst;
if (rstmux)
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 &ceA = cemux->connections_.at(\A);
SigSpec &ceB = cemux->connections_.at(\B);
SigSpec &ceY = cemux->connections_.at(\Y);
SigSpec &dffD = dff->connections_.at(\D);
SigSpec &dffQ = dff->connections_.at(\Q);
Const init;
for (const auto &b : Q) {
auto it = b.wire->attributes.find(\init);
init.bits.push_back(it == b.wire->attributes.end() ? State::Sx : it->second[b.offset]);
}
if (D[width-1] == D[width-2]) {
auto cmpx = [=](State lhs, State rhs) {
if (lhs == State::Sx || rhs == State::Sx)
return true;
return lhs == rhs;
};
int i = width;
while (i > 2) {
i--;
if (D[i] != D[i-1])
break;
if (!cmpx(rst[i], rst[i-1]))
break;
if (!cmpx(init[i], init[i-1]))
break;
if (!cmpx(rst[i], init[i]))
break;
module->connect(Q[i], Q[i-1]);
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 || (rst.size() && rst[i-1] != rst[width-1]))
break;
}
else {
module->connect(Q[i], Q[i-1]);
if (D[i-2] != sign || (rst.size() && rst[i-1] != rst[width-1]))
break;
}
}
if (i < width-1) {
if (cemux) {
SigSpec &ceA = cemux->connections_.at(\A);
SigSpec &ceB = cemux->connections_.at(\B);
SigSpec &ceY = cemux->connections_.at(\Y);
ceA.remove(i, width-i);
ceB.remove(i, width-i);
ceY.remove(i, width-i);
cemux->fixup_parameters();
}
ceA.remove(i, width-i);
ceB.remove(i, width-i);
ceY.remove(i, width-i);
cemux->fixup_parameters();
dffD.remove(i, width-i);
dffQ.remove(i, width-i);
dff->fixup_parameters();
@ -78,7 +105,11 @@ code
log("dffcemux pattern in %s: dff=%s, cemux=%s; removed top %d bits.\n", log_id(module), log_id(dff), log_id(cemux), width-i);
accept;
}
else {
else if (cemux) {
SigSpec &ceA = cemux->connections_.at(\A);
SigSpec &ceB = cemux->connections_.at(\B);
SigSpec &ceY = cemux->connections_.at(\Y);
int count = 0;
for (int i = width-1; i >= 0; i--) {
if (D[i].wire)