yosys/passes/pmgen/ice40_dsp.pmg

419 lines
9.8 KiB
Plaintext

pattern ice40_dsp
state <SigBit> clock
state <bool> clock_pol cd_signed o_lo
state <SigSpec> sigA sigB sigCD sigH sigO
state <Cell*> add mux
state <IdString> addAB muxAB
state <Cell*> ffA ffB ffCD
state <Cell*> ffFJKG ffH ffO
// subpattern
state <bool> argSdff
state <SigSpec> argQ argD
udata <SigSpec> dffD dffQ
udata <SigBit> dffclock
udata <Cell*> dff
udata <bool> dffclock_pol
match mul
select mul->type.in($mul, \SB_MAC16)
select GetSize(mul->getPort(\A)) + GetSize(mul->getPort(\B)) > 10
endmatch
code sigA sigB sigH
auto unextend = [](const SigSpec &sig) {
int i;
for (i = GetSize(sig)-1; i > 0; i--)
if (sig[i] != sig[i-1])
break;
// Do not remove non-const sign bit
if (sig[i].wire)
++i;
return sig.extract(0, i);
};
sigA = unextend(port(mul, \A));
sigB = unextend(port(mul, \B));
SigSpec O;
if (mul->type == $mul)
O = mul->getPort(\Y);
else if (mul->type == \SB_MAC16)
O = mul->getPort(\O);
else log_abort();
if (GetSize(O) <= 10)
reject;
// Only care about those bits that are used
int i;
for (i = 0; i < GetSize(O); i++) {
if (nusers(O[i]) <= 1)
break;
sigH.append(O[i]);
}
// This sigM could have no users if downstream sinks (e.g. $add) is
// narrower than $mul result, for example
if (i == 0)
reject;
log_assert(nusers(O.extract_end(i)) <= 1);
endcode
code argQ ffA sigA clock clock_pol
if (mul->type != \SB_MAC16 || !param(mul, \A_REG).as_bool()) {
argQ = sigA;
subpattern(in_dffe);
if (dff) {
ffA = dff;
clock = dffclock;
clock_pol = dffclock_pol;
sigA = dffD;
}
}
endcode
code argQ ffB sigB clock clock_pol
if (mul->type != \SB_MAC16 || !param(mul, \B_REG).as_bool()) {
argQ = sigB;
subpattern(in_dffe);
if (dff) {
ffB = dff;
clock = dffclock;
clock_pol = dffclock_pol;
sigB = dffD;
}
}
endcode
code argD argSdff ffFJKG sigH clock clock_pol
if (nusers(sigH) == 2 &&
(mul->type != \SB_MAC16 ||
(!param(mul, \TOP_8x8_MULT_REG).as_bool() && !param(mul, \BOT_8x8_MULT_REG).as_bool() && !param(mul, \PIPELINE_16x16_MULT_REG1).as_bool() && !param(mul, \PIPELINE_16x16_MULT_REG1).as_bool()))) {
argD = sigH;
argSdff = false;
subpattern(out_dffe);
if (dff) {
// F/J/K/G do not have a CE-like (hold) input
if (dff->hasPort(\EN))
goto reject_ffFJKG;
// Reset signal of F/J (IRSTTOP) and K/G (IRSTBOT)
// shared with A and B
if (ffA) {
if (ffA->hasPort(\ARST) != dff->hasPort(\ARST))
goto reject_ffFJKG;
if (ffA->hasPort(\ARST)) {
if (port(ffA, \ARST) != port(dff, \ARST))
goto reject_ffFJKG;
if (param(ffA, \ARST_POLARITY) != param(dff, \ARST_POLARITY))
goto reject_ffFJKG;
}
}
if (ffB) {
if (ffB->hasPort(\ARST) != dff->hasPort(\ARST))
goto reject_ffFJKG;
if (ffB->hasPort(\ARST)) {
if (port(ffB, \ARST) != port(dff, \ARST))
goto reject_ffFJKG;
if (param(ffB, \ARST_POLARITY) != param(dff, \ARST_POLARITY))
goto reject_ffFJKG;
}
}
ffFJKG = dff;
clock = dffclock;
clock_pol = dffclock_pol;
sigH = dffQ;
reject_ffFJKG: ;
}
}
endcode
code argD argSdff ffH sigH sigO clock clock_pol
if (ffFJKG && nusers(sigH) == 2 &&
(mul->type != \SB_MAC16 || !param(mul, \PIPELINE_16x16_MULT_REG2).as_bool())) {
argD = sigH;
argSdff = false;
subpattern(out_dffe);
if (dff) {
// H does not have a CE-like (hold) input
if (dff->hasPort(\EN))
goto reject_ffH;
// Reset signal of H (IRSTBOT) shared with B
if (ffB->hasPort(\ARST) != dff->hasPort(\ARST))
goto reject_ffH;
if (ffB->hasPort(\ARST)) {
if (port(ffB, \ARST) != port(dff, \ARST))
goto reject_ffH;
if (param(ffB, \ARST_POLARITY) != param(dff, \ARST_POLARITY))
goto reject_ffH;
}
ffH = dff;
clock = dffclock;
clock_pol = dffclock_pol;
sigH = dffQ;
reject_ffH: ;
}
}
sigO = sigH;
endcode
match add
if mul->type != \SB_MAC16 || (param(mul, \TOPOUTPUT_SELECT).as_int() == 3 && param(mul, \BOTOUTPUT_SELECT).as_int() == 3)
select add->type.in($add)
choice <IdString> AB {\A, \B}
select nusers(port(add, AB)) == 2
index <SigBit> port(add, AB)[0] === sigH[0]
filter GetSize(port(add, AB)) <= GetSize(sigH)
filter port(add, AB) == sigH.extract(0, GetSize(port(add, AB)))
filter nusers(sigH.extract_end(GetSize(port(add, AB)))) <= 1
set addAB AB
optional
endmatch
code sigCD sigO cd_signed
if (add) {
sigCD = port(add, addAB == \A ? \B : \A);
cd_signed = param(add, addAB == \A ? \B_SIGNED : \A_SIGNED).as_bool();
int natural_mul_width = GetSize(sigA) + GetSize(sigB);
int actual_mul_width = GetSize(sigH);
int actual_acc_width = GetSize(sigCD);
if ((actual_acc_width > actual_mul_width) && (natural_mul_width > actual_mul_width))
reject;
// If accumulator, check adder width and signedness
if (sigCD == sigH && (actual_acc_width != actual_mul_width) && (param(mul, \A_SIGNED).as_bool() != param(add, \A_SIGNED).as_bool()))
reject;
sigO = port(add, \Y);
}
endcode
match mux
select mux->type == $mux
choice <IdString> AB {\A, \B}
select nusers(port(mux, AB)) == 2
index <SigSpec> port(mux, AB) === sigO
set muxAB AB
optional
endmatch
code sigO
if (mux)
sigO = port(mux, \Y);
endcode
code argD argSdff ffO sigO sigCD clock clock_pol cd_signed o_lo
if (mul->type != \SB_MAC16 ||
// Ensure that register is not already used
((param(mul, \TOPOUTPUT_SELECT).as_int() != 1 && param(mul, \BOTOUTPUT_SELECT).as_int() != 1) &&
// Ensure that OLOADTOP/OLOADBOT is unused or zero
(port(mul, \OLOADTOP, State::S0).is_fully_zero() && port(mul, \OLOADBOT, State::S0).is_fully_zero()))) {
dff = nullptr;
// First try entire sigO
if (nusers(sigO) == 2) {
argD = sigO;
argSdff = !mux;
subpattern(out_dffe);
}
// Otherwise try just its least significant 16 bits
if (!dff && GetSize(sigO) > 16) {
argD = sigO.extract(0, 16);
if (nusers(argD) == 2) {
argSdff = !mux;
subpattern(out_dffe);
o_lo = dff;
}
}
if (dff) {
ffO = dff;
clock = dffclock;
clock_pol = dffclock_pol;
sigO.replace(sigO.extract(0, GetSize(dffQ)), dffQ);
}
// Loading value into output register is not
// supported unless using accumulator
if (mux) {
if (sigCD != sigO)
reject;
sigCD = port(mux, muxAB == \B ? \A : \B);
cd_signed = add && param(add, \A_SIGNED).as_bool() && param(add, \B_SIGNED).as_bool();
} else if (dff && dff->hasPort(\SRST)) {
if (sigCD != sigO)
reject;
sigCD = param(dff, \SRST_VALUE);
cd_signed = add && param(add, \A_SIGNED).as_bool() && param(add, \B_SIGNED).as_bool();
}
}
endcode
code argQ ffCD sigCD clock clock_pol
if (!sigCD.empty() && sigCD != sigO &&
(mul->type != \SB_MAC16 || (!param(mul, \C_REG).as_bool() && !param(mul, \D_REG).as_bool()))) {
argQ = sigCD;
subpattern(in_dffe);
if (dff) {
// Reset signal of C (IRSTTOP) and D (IRSTBOT)
// shared with A and B
if (ffA) {
if (ffA->hasPort(\ARST) != dff->hasPort(\ARST))
goto reject_ffCD;
if (ffA->hasPort(\ARST)) {
if (port(ffA, \ARST) != port(dff, \ARST))
goto reject_ffCD;
if (param(ffA, \ARST_POLARITY) != param(dff, \ARST_POLARITY))
goto reject_ffCD;
}
}
if (ffB) {
if (ffB->hasPort(\ARST) != dff->hasPort(\ARST))
goto reject_ffCD;
if (ffB->hasPort(\ARST)) {
if (port(ffB, \ARST) != port(dff, \ARST))
goto reject_ffCD;
if (param(ffB, \ARST_POLARITY) != param(dff, \ARST_POLARITY))
goto reject_ffCD;
}
}
ffCD = dff;
clock = dffclock;
clock_pol = dffclock_pol;
sigCD = dffD;
reject_ffCD: ;
}
}
endcode
code sigCD
sigCD.extend_u0(32, cd_signed);
endcode
code
accept;
endcode
// #######################
subpattern in_dffe
arg argD argQ clock clock_pol
code
dff = nullptr;
if (argQ.empty())
reject;
for (auto c : argQ.chunks()) {
if (!c.wire)
reject;
if (c.wire->get_bool_attribute(\keep))
reject;
Const init = c.wire->attributes.at(\init, State::Sx);
if (!init.is_fully_undef() && !init.is_fully_zero())
reject;
}
endcode
match ff
select ff->type.in($dff, $dffe)
// DSP48E1 does not support clock inversion
select param(ff, \CLK_POLARITY).as_bool()
slice offset GetSize(port(ff, \D))
index <SigBit> port(ff, \Q)[offset] === argQ[0]
// Check that the rest of argQ is present
filter GetSize(port(ff, \Q)) >= offset + GetSize(argQ)
filter port(ff, \Q).extract(offset, GetSize(argQ)) == argQ
endmatch
code argQ argD
{
if (clock != SigBit()) {
if (port(ff, \CLK) != clock)
reject;
if (param(ff, \CLK_POLARITY).as_bool() != clock_pol)
reject;
}
SigSpec Q = port(ff, \Q);
dff = ff;
dffclock = port(ff, \CLK);
dffclock_pol = param(ff, \CLK_POLARITY).as_bool();
dffD = argQ;
argD = port(ff, \D);
argQ = Q;
dffD.replace(argQ, argD);
}
endcode
// #######################
subpattern out_dffe
arg argD argSdff argQ clock clock_pol
code
dff = nullptr;
for (auto c : argD.chunks())
if (c.wire->get_bool_attribute(\keep))
reject;
endcode
match ff
select ff->type.in($dff, $dffe, $sdff, $sdffce)
// SB_MAC16 does not support clock inversion
select param(ff, \CLK_POLARITY).as_bool()
slice offset GetSize(port(ff, \D))
index <SigBit> port(ff, \D)[offset] === argD[0]
// Only allow sync reset if requested.
filter argSdff || ff->type.in($dff, $dffe)
// Check that the rest of argD is present
filter GetSize(port(ff, \D)) >= offset + GetSize(argD)
filter port(ff, \D).extract(offset, GetSize(argD)) == argD
endmatch
code argQ
if (ff) {
if (clock != SigBit()) {
if (port(ff, \CLK) != clock)
reject;
if (param(ff, \CLK_POLARITY).as_bool() != clock_pol)
reject;
}
SigSpec D = port(ff, \D);
SigSpec Q = port(ff, \Q);
argQ = argD;
argQ.replace(D, Q);
for (auto c : argQ.chunks()) {
Const init = c.wire->attributes.at(\init, State::Sx);
if (!init.is_fully_undef() && !init.is_fully_zero())
reject;
}
dff = ff;
dffQ = argQ;
dffclock = port(ff, \CLK);
dffclock_pol = param(ff, \CLK_POLARITY).as_bool();
}
endcode