PRIVATE_NAMESPACE_BEGIN
#include "passes/pmgen/xilinx_dsp_pm.h"
+#include "passes/pmgen/xilinx_dsp48a_pm.h"
#include "passes/pmgen/xilinx_dsp_CREG_pm.h"
#include "passes/pmgen/xilinx_dsp_cascade_pm.h"
pm.blacklist(cell);
}
+void xilinx_dsp48a_pack(xilinx_dsp48a_pm &pm)
+{
+ auto &st = pm.st_xilinx_dsp48a_pack;
+
+ log("Analysing %s.%s for Xilinx DSP48A/DSP48A1 packing.\n", log_id(pm.module), log_id(st.dsp));
+
+ log_debug("preAdd: %s\n", log_id(st.preAdd, "--"));
+ log_debug("ffA1: %s %s %s\n", log_id(st.ffA1, "--"), log_id(st.ffA1cemux, "--"), log_id(st.ffA1rstmux, "--"));
+ log_debug("ffA0: %s %s %s\n", log_id(st.ffA0, "--"), log_id(st.ffA0cemux, "--"), log_id(st.ffA0rstmux, "--"));
+ log_debug("ffB1: %s %s %s\n", log_id(st.ffB1, "--"), log_id(st.ffB1cemux, "--"), log_id(st.ffB1rstmux, "--"));
+ log_debug("ffB0: %s %s %s\n", log_id(st.ffB0, "--"), log_id(st.ffB0cemux, "--"), log_id(st.ffB0rstmux, "--"));
+ log_debug("ffD: %s %s %s\n", log_id(st.ffD, "--"), log_id(st.ffDcemux, "--"), log_id(st.ffDrstmux, "--"));
+ log_debug("dsp: %s\n", log_id(st.dsp, "--"));
+ log_debug("ffM: %s %s %s\n", log_id(st.ffM, "--"), log_id(st.ffMcemux, "--"), log_id(st.ffMrstmux, "--"));
+ log_debug("postAdd: %s\n", log_id(st.postAdd, "--"));
+ log_debug("postAddMux: %s\n", log_id(st.postAddMux, "--"));
+ log_debug("ffP: %s %s %s\n", log_id(st.ffP, "--"), log_id(st.ffPcemux, "--"), log_id(st.ffPrstmux, "--"));
+
+ Cell *cell = st.dsp;
+ SigSpec &opmode = cell->connections_.at(ID(OPMODE));
+
+ if (st.preAdd) {
+ log(" preadder %s (%s)\n", log_id(st.preAdd), log_id(st.preAdd->type));
+ bool D_SIGNED = st.preAdd->getParam(ID(A_SIGNED)).as_bool();
+ bool B_SIGNED = st.preAdd->getParam(ID(B_SIGNED)).as_bool();
+ st.sigB.extend_u0(18, B_SIGNED);
+ st.sigD.extend_u0(18, D_SIGNED);
+ cell->setPort(ID(B), st.sigB);
+ cell->setPort(ID(D), st.sigD);
+ opmode[4] = State::S1;
+ if (st.preAdd->type == ID($add))
+ opmode[6] = State::S0;
+ else if (st.preAdd->type == ID($sub))
+ opmode[6] = State::S1;
+ else
+ log_assert(!"strange pre-adder type");
+
+ pm.autoremove(st.preAdd);
+ }
+ if (st.postAdd) {
+ log(" postadder %s (%s)\n", log_id(st.postAdd), log_id(st.postAdd->type));
+
+ if (st.postAddMux) {
+ log_assert(st.ffP);
+ opmode[2] = st.postAddMux->getPort(ID(S));
+ pm.autoremove(st.postAddMux);
+ }
+ else if (st.ffP && st.sigC == st.sigP)
+ opmode[2] = State::S0;
+ else
+ opmode[2] = State::S1;
+ opmode[3] = State::S1;
+
+ if (opmode[2] != State::S0) {
+ if (st.postAddMuxAB == ID(A))
+ st.sigC.extend_u0(48, st.postAdd->getParam(ID(B_SIGNED)).as_bool());
+ else
+ st.sigC.extend_u0(48, st.postAdd->getParam(ID(A_SIGNED)).as_bool());
+ cell->setPort(ID(C), st.sigC);
+ }
+
+ pm.autoremove(st.postAdd);
+ }
+
+ if (st.clock != SigBit())
+ {
+ cell->setPort(ID(CLK), st.clock);
+
+ auto f = [&pm,cell](SigSpec &A, Cell* ff, Cell* cemux, bool cepol, IdString ceport, Cell* rstmux, bool rstpol, IdString rstport) {
+ SigSpec D = ff->getPort(ID(D));
+ SigSpec Q = pm.sigmap(ff->getPort(ID(Q)));
+ if (!A.empty())
+ A.replace(Q, D);
+ if (rstmux) {
+ SigSpec Y = rstmux->getPort(ID(Y));
+ SigSpec AB = rstmux->getPort(rstpol ? ID(A) : ID(B));
+ if (!A.empty())
+ A.replace(Y, AB);
+ if (rstport != IdString()) {
+ SigSpec S = rstmux->getPort(ID(S));
+ cell->setPort(rstport, rstpol ? S : pm.module->Not(NEW_ID, S));
+ }
+ }
+ else if (rstport != IdString())
+ cell->setPort(rstport, State::S0);
+ if (cemux) {
+ SigSpec Y = cemux->getPort(ID(Y));
+ SigSpec BA = cemux->getPort(cepol ? ID(B) : ID(A));
+ SigSpec S = cemux->getPort(ID(S));
+ if (!A.empty())
+ A.replace(Y, BA);
+ cell->setPort(ceport, cepol ? S : pm.module->Not(NEW_ID, S));
+ }
+ else
+ cell->setPort(ceport, State::S1);
+
+ for (auto c : Q.chunks()) {
+ auto it = c.wire->attributes.find(ID(init));
+ if (it == c.wire->attributes.end())
+ continue;
+ for (int i = c.offset; i < c.offset+c.width; i++) {
+ log_assert(it->second[i] == State::S0 || it->second[i] == State::Sx);
+ it->second[i] = State::Sx;
+ }
+ }
+ };
+
+ if (st.ffA0 || st.ffA1) {
+ SigSpec A = cell->getPort(ID(A));
+ if (st.ffA1) {
+ f(A, st.ffA1, st.ffA1cemux, st.ffAcepol, ID(CEA), st.ffA1rstmux, st.ffArstpol, ID(RSTA));
+ cell->setParam(ID(A1REG), 1);
+ }
+ if (st.ffA0) {
+ f(A, st.ffA0, st.ffA0cemux, st.ffAcepol, ID(CEA), st.ffA0rstmux, st.ffArstpol, ID(RSTA));
+ cell->setParam(ID(A0REG), 1);
+ }
+ pm.add_siguser(A, cell);
+ cell->setPort(ID(A), A);
+ }
+ if (st.ffB0 || st.ffB1) {
+ SigSpec B = cell->getPort(ID(B));
+ if (st.ffB1) {
+ f(B, st.ffB1, st.ffB1cemux, st.ffBcepol, ID(CEB), st.ffB1rstmux, st.ffBrstpol, ID(RSTB));
+ cell->setParam(ID(B1REG), 1);
+ }
+ if (st.ffB0) {
+ f(B, st.ffB0, st.ffB0cemux, st.ffBcepol, ID(CEB), st.ffB0rstmux, st.ffBrstpol, ID(RSTB));
+ cell->setParam(ID(B0REG), 1);
+ }
+ pm.add_siguser(B, cell);
+ cell->setPort(ID(B), B);
+ }
+ if (st.ffD) {
+ SigSpec D = cell->getPort(ID(D));
+ f(D, st.ffD, st.ffDcemux, st.ffDcepol, ID(CED), st.ffDrstmux, st.ffDrstpol, ID(RSTD));
+ pm.add_siguser(D, cell);
+ cell->setPort(ID(D), D);
+ cell->setParam(ID(DREG), 1);
+ }
+ if (st.ffM) {
+ SigSpec M; // unused
+ f(M, st.ffM, st.ffMcemux, st.ffMcepol, ID(CEM), st.ffMrstmux, st.ffMrstpol, ID(RSTM));
+ st.ffM->connections_.at(ID(Q)).replace(st.sigM, pm.module->addWire(NEW_ID, GetSize(st.sigM)));
+ cell->setParam(ID(MREG), State::S1);
+ }
+ if (st.ffP) {
+ SigSpec P; // unused
+ f(P, st.ffP, st.ffPcemux, st.ffPcepol, ID(CEP), st.ffPrstmux, st.ffPrstpol, ID(RSTP));
+ st.ffP->connections_.at(ID(Q)).replace(st.sigP, pm.module->addWire(NEW_ID, GetSize(st.sigP)));
+ cell->setParam(ID(PREG), State::S1);
+ }
+
+ log(" clock: %s (%s)", log_signal(st.clock), "posedge");
+
+ if (st.ffA0)
+ log(" ffA0:%s", log_id(st.ffA0));
+ if (st.ffA1)
+ log(" ffA1:%s", log_id(st.ffA1));
+
+ if (st.ffB0)
+ log(" ffB0:%s", log_id(st.ffB0));
+ if (st.ffB1)
+ log(" ffB1:%s", log_id(st.ffB1));
+
+ if (st.ffD)
+ log(" ffD:%s", log_id(st.ffD));
+
+ if (st.ffM)
+ log(" ffM:%s", log_id(st.ffM));
+
+ if (st.ffP)
+ log(" ffP:%s", log_id(st.ffP));
+ }
+ log("\n");
+
+ SigSpec P = st.sigP;
+ if (GetSize(P) < 48)
+ P.append(pm.module->addWire(NEW_ID, 48-GetSize(P)));
+ cell->setPort(ID(P), P);
+
+ pm.blacklist(cell);
+}
+
void xilinx_dsp_packC(xilinx_dsp_CREG_pm &pm)
{
auto &st = pm.st_xilinx_dsp_packC;
log("P output implementing the operation \"(P >= <power-of-2>)\" will be transformed\n");
log("into using the DSP48E1's pattern detector feature for overflow detection.\n");
log("\n");
+ log(" -family {xcup|xcu|xc7|xc6v|xc5v|xc4v|xc6s|xc3sda}\n");
+ log(" select the family to target\n");
+ log(" default: xc7\n");
+ log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
log_header(design, "Executing XILINX_DSP pass (pack resources into DSPs).\n");
+ std::string family = "xc7";
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++)
{
- // if (args[argidx] == "-singleton") {
- // singleton_mode = true;
- // continue;
- // }
+ if ((args[argidx] == "-family" || args[argidx] == "-arch") && argidx+1 < args.size()) {
+ family = args[++argidx];
+ continue;
+ }
break;
}
extra_args(args, argidx, design);
+ // Don't bother distinguishing between those.
+ if (family == "xc6v")
+ family = "xc7";
+ if (family == "xcup")
+ family = "xcu";
+
for (auto module : design->selected_modules()) {
// Experimental feature: pack $add/$sub cells with
// (* use_dsp48="simd" *) into DSP48E1's using its
// SIMD feature
- xilinx_simd_pack(module, module->selected_cells());
+ if (family == "xc7")
+ xilinx_simd_pack(module, module->selected_cells());
// Match for all features ([ABDMP][12]?REG, pre-adder,
// post-adder, pattern detector, etc.) except for CREG
- {
+ if (family == "xc7") {
xilinx_dsp_pm pm(module, module->selected_cells());
pm.run_xilinx_dsp_pack(xilinx_dsp_pack);
+ } else if (family == "xc6s" || family == "xc3sda") {
+ xilinx_dsp48a_pm pm(module, module->selected_cells());
+ pm.run_xilinx_dsp48a_pack(xilinx_dsp48a_pack);
}
// Separating out CREG packing is necessary since there
// is no guarantee that the cell ordering corresponds
--- /dev/null
+// This file describes the main pattern matcher setup (of three total) that
+// forms the `xilinx_dsp` pass described in xilinx_dsp.cc — version for
+// DSP48A/DSP48A1 (Spartan 3A DSP, Spartan 6).
+// At a high level, it works as follows:
+// ( 1) Starting from a DSP48A/DSP48A1 cell
+// ( 2) Match the driver of the 'B' input to a possible $dff cell (B1REG)
+// (attached to at most two $mux cells that implement clock-enable or
+// reset functionality, using a subpattern discussed below)
+// If B1REG matched, treat 'B' input as input of B1REG
+// ( 3) Match the driver of the 'B' and 'D' inputs for a possible $add cell
+// (pre-adder)
+// ( 4) Match 'B' input for B0REG
+// ( 5) Match 'A' input for A1REG
+// If A1REG, then match 'A' input for A0REG
+// ( 6) Match 'D' input for DREG
+// ( 7) Match 'P' output that exclusively drives an MREG
+// ( 8) Match 'P' output that exclusively drives one of two inputs to an $add
+// cell (post-adder).
+// The other input to the adder is assumed to come in from the 'C' input
+// (note: 'P' -> 'C' connections that exist for accumulators are
+// recognised in xilinx_dsp.cc).
+// ( 9) Match 'P' output that exclusively drives a PREG
+// (10) If post-adder and PREG both present, match for a $mux cell driving
+// the 'C' input, where one of the $mux's inputs is the PREG output.
+// This indicates an accumulator situation, and one where a $mux exists
+// to override the accumulated value:
+// +--------------------------------+
+// | ____ |
+// +--| \ |
+// |$mux|-+ |
+// 'C' ---|____/ | |
+// | /-------\ +----+ |
+// +----+ +-| post- |___|PREG|---+ 'P'
+// |MREG|------ | adder | +----+
+// +----+ \-------/
+// Notes: see the notes in xilinx_dsp.pmg
+
+pattern xilinx_dsp48a_pack
+
+state <SigBit> clock
+state <SigSpec> sigA sigB sigC sigD sigM sigP
+state <IdString> postAddAB postAddMuxAB
+state <bool> ffAcepol ffBcepol ffDcepol ffMcepol ffPcepol
+state <bool> ffArstpol ffBrstpol ffDrstpol ffMrstpol ffPrstpol
+state <Cell*> ffA0 ffA0cemux ffA0rstmux ffA1 ffA1cemux ffA1rstmux
+state <Cell*> ffB0 ffB0cemux ffB0rstmux ffB1 ffB1cemux ffB1rstmux
+state <Cell*> ffD ffDcemux ffDrstmux ffM ffMcemux ffMrstmux ffP ffPcemux ffPrstmux
+
+// Variables used for subpatterns
+state <SigSpec> argQ argD
+state <bool> ffcepol ffrstpol
+state <int> ffoffset
+udata <SigSpec> dffD dffQ
+udata <SigBit> dffclock
+udata <Cell*> dff dffcemux dffrstmux
+udata <bool> dffcepol dffrstpol
+
+// (1) Starting from a DSP48A/DSP48A1 cell
+match dsp
+ select dsp->type.in(\DSP48A, \DSP48A1)
+endmatch
+
+code sigA sigB sigC sigD sigM clock
+ 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(dsp, \A));
+ sigB = unextend(port(dsp, \B));
+
+ sigC = port(dsp, \C, SigSpec());
+ sigD = port(dsp, \D, SigSpec());
+
+ SigSpec P = port(dsp, \P);
+ // Only care about those bits that are used
+ int i;
+ for (i = GetSize(P)-1; i >= 0; i--)
+ if (nusers(P[i]) > 1)
+ break;
+ i++;
+ log_assert(nusers(P.extract_end(i)) <= 1);
+ // This sigM could have no users if downstream sinks (e.g. $add) is
+ // narrower than $mul result, for example
+ if (i == 0)
+ reject;
+ sigM = P.extract(0, i);
+
+ clock = port(dsp, \CLK, SigBit());
+endcode
+
+// (2) Match the driver of the 'B' input to a possible $dff cell (B1REG)
+// (attached to at most two $mux cells that implement clock-enable or
+// reset functionality, using a subpattern discussed above)
+// If matched, treat 'B' input as input of B1REG
+code argQ ffB1 ffB1cemux ffB1rstmux ffBcepol ffBrstpol sigB clock
+ if (param(dsp, \B1REG).as_int() == 0 && param(dsp, \B0REG).as_int() == 0 && port(dsp, \OPMODE, SigSpec()).extract(4, 1).is_fully_zero()) {
+ argQ = sigB;
+ subpattern(in_dffe);
+ if (dff) {
+ ffB1 = dff;
+ clock = dffclock;
+ if (dffrstmux) {
+ ffB1rstmux = dffrstmux;
+ ffBrstpol = dffrstpol;
+ }
+ if (dffcemux) {
+ ffB1cemux = dffcemux;
+ ffBcepol = dffcepol;
+ }
+ sigB = dffD;
+ }
+ }
+endcode
+
+// (3) Match the driver of the 'B' and 'D' inputs for a possible $add cell
+// (pre-adder)
+match preAdd
+ if sigD.empty() || sigD.is_fully_zero()
+ if param(dsp, \B0REG).as_int() == 0
+ // Ensure that preAdder not already used
+ if port(dsp, \OPMODE, SigSpec()).extract(4, 1).is_fully_zero()
+
+ select preAdd->type.in($add, $sub)
+ // Output has to be 18 bits or less
+ select GetSize(port(preAdd, \Y)) <= 18
+ select nusers(port(preAdd, \Y)) == 2
+ // D port has to be 18 bits or less
+ select GetSize(port(preAdd, \A)) <= 18
+ // B port has to be 18 bits or less
+ select GetSize(port(preAdd, \B)) <= 18
+ index <SigSpec> port(preAdd, \Y) === sigB
+
+ optional
+endmatch
+
+code sigB sigD
+ if (preAdd) {
+ sigD = port(preAdd, \A);
+ sigB = port(preAdd, \B);
+ }
+endcode
+
+// (4) Match 'B' input for B0REG
+code argQ ffB0 ffB0cemux ffB0rstmux ffBcepol ffBrstpol sigB clock
+ if (param(dsp, \B0REG).as_int() == 0) {
+ argQ = sigB;
+ subpattern(in_dffe);
+ if (dff) {
+ if (ffB1) {
+ if ((ffB1rstmux != nullptr) ^ (dffrstmux != nullptr))
+ goto ffB0_end;
+ if ((ffB1cemux != nullptr) ^ (dffcemux != nullptr))
+ goto ffB0_end;
+ if (dffrstmux) {
+ if (ffBrstpol != dffrstpol)
+ goto ffB0_end;
+ if (port(ffB1rstmux, \S) != port(dffrstmux, \S))
+ goto ffB0_end;
+ ffB0rstmux = dffrstmux;
+ }
+ if (dffcemux) {
+ if (ffBcepol != dffcepol)
+ goto ffB0_end;
+ if (port(ffB1cemux, \S) != port(dffcemux, \S))
+ goto ffB0_end;
+ ffB0cemux = dffcemux;
+ }
+ }
+ ffB0 = dff;
+ clock = dffclock;
+ if (dffrstmux) {
+ ffB0rstmux = dffrstmux;
+ ffBrstpol = dffrstpol;
+ }
+ if (dffcemux) {
+ ffB0cemux = dffcemux;
+ ffBcepol = dffcepol;
+ }
+ sigB = dffD;
+ }
+ }
+ffB0_end:
+endcode
+
+// (5) Match 'A' input for A1REG
+// If A1REG, then match 'A' input for A0REG
+code argQ ffA1 ffA1cemux ffA1rstmux ffAcepol ffArstpol sigA clock ffA0 ffA0cemux ffA0rstmux
+ if (param(dsp, \A0REG).as_int() == 0 && param(dsp, \A1REG).as_int() == 0) {
+ argQ = sigA;
+ subpattern(in_dffe);
+ if (dff) {
+ ffA1 = dff;
+ clock = dffclock;
+ if (dffrstmux) {
+ ffA1rstmux = dffrstmux;
+ ffArstpol = dffrstpol;
+ }
+ if (dffcemux) {
+ ffA1cemux = dffcemux;
+ ffAcepol = dffcepol;
+ }
+ sigA = dffD;
+
+ // Now attempt to match A0
+ if (ffA1) {
+ argQ = sigA;
+ subpattern(in_dffe);
+ if (dff) {
+ if ((ffA1rstmux != nullptr) ^ (dffrstmux != nullptr))
+ goto ffA0_end;
+ if ((ffA1cemux != nullptr) ^ (dffcemux != nullptr))
+ goto ffA0_end;
+ if (dffrstmux) {
+ if (ffArstpol != dffrstpol)
+ goto ffA0_end;
+ if (port(ffA1rstmux, \S) != port(dffrstmux, \S))
+ goto ffA0_end;
+ ffA0rstmux = dffrstmux;
+ }
+ if (dffcemux) {
+ if (ffAcepol != dffcepol)
+ goto ffA0_end;
+ if (port(ffA1cemux, \S) != port(dffcemux, \S))
+ goto ffA0_end;
+ ffA0cemux = dffcemux;
+ }
+
+ ffA0 = dff;
+ clock = dffclock;
+
+ if (dffcemux) {
+ ffA0cemux = dffcemux;
+ ffAcepol = dffcepol;
+ }
+ sigA = dffD;
+
+ffA0_end: ;
+ }
+ }
+
+ }
+ }
+endcode
+
+// (6) Match 'D' input for DREG
+code argQ ffD ffDcemux ffDrstmux ffDcepol ffDrstpol sigD clock
+ if (param(dsp, \DREG).as_int() == 0) {
+ argQ = sigD;
+ subpattern(in_dffe);
+ if (dff) {
+ ffD = dff;
+ clock = dffclock;
+ if (dffrstmux) {
+ ffDrstmux = dffrstmux;
+ ffDrstpol = dffrstpol;
+ }
+ if (dffcemux) {
+ ffDcemux = dffcemux;
+ ffDcepol = dffcepol;
+ }
+ sigD = dffD;
+ }
+ }
+endcode
+
+// (7) Match 'P' output that exclusively drives an MREG
+code argD ffM ffMcemux ffMrstmux ffMcepol ffMrstpol sigM sigP clock
+ if (param(dsp, \MREG).as_int() == 0 && nusers(sigM) == 2) {
+ argD = sigM;
+ subpattern(out_dffe);
+ if (dff) {
+ ffM = dff;
+ clock = dffclock;
+ if (dffrstmux) {
+ ffMrstmux = dffrstmux;
+ ffMrstpol = dffrstpol;
+ }
+ if (dffcemux) {
+ ffMcemux = dffcemux;
+ ffMcepol = dffcepol;
+ }
+ sigM = dffQ;
+ }
+ }
+ sigP = sigM;
+endcode
+
+// (8) Match 'P' output that exclusively drives one of two inputs to an $add
+// cell (post-adder).
+// The other input to the adder is assumed to come in from the 'C' input
+// (note: 'P' -> 'C' connections that exist for accumulators are
+// recognised in xilinx_dsp.cc).
+match postAdd
+ // Ensure that Z mux is not already used
+ if port(dsp, \OPMODE, SigSpec()).extract(2,2).is_fully_zero()
+
+ select postAdd->type.in($add)
+ select GetSize(port(postAdd, \Y)) <= 48
+ choice <IdString> AB {\A, \B}
+ select nusers(port(postAdd, AB)) <= 3
+ filter ffMcemux || nusers(port(postAdd, AB)) == 2
+ filter !ffMcemux || nusers(port(postAdd, AB)) == 3
+
+ index <SigBit> port(postAdd, AB)[0] === sigP[0]
+ filter GetSize(port(postAdd, AB)) >= GetSize(sigP)
+ filter port(postAdd, AB).extract(0, GetSize(sigP)) == sigP
+ // Check that remainder of AB is a sign- or zero-extension
+ filter port(postAdd, AB).extract_end(GetSize(sigP)) == SigSpec(sigP[GetSize(sigP)-1], GetSize(port(postAdd, AB))-GetSize(sigP)) || port(postAdd, AB).extract_end(GetSize(sigP)) == SigSpec(State::S0, GetSize(port(postAdd, AB))-GetSize(sigP))
+
+ set postAddAB AB
+ optional
+endmatch
+
+code sigC sigP
+ if (postAdd) {
+ sigC = port(postAdd, postAddAB == \A ? \B : \A);
+ sigP = port(postAdd, \Y);
+ }
+endcode
+
+// (9) Match 'P' output that exclusively drives a PREG
+code argD ffP ffPcemux ffPrstmux ffPcepol ffPrstpol sigP clock
+ if (param(dsp, \PREG).as_int() == 0) {
+ int users = 2;
+ // If ffMcemux and no postAdd new-value net must have three users: ffMcemux, ffM and ffPcemux
+ if (ffMcemux && !postAdd) users++;
+ if (nusers(sigP) == users) {
+ argD = sigP;
+ subpattern(out_dffe);
+ if (dff) {
+ ffP = dff;
+ clock = dffclock;
+ if (dffrstmux) {
+ ffPrstmux = dffrstmux;
+ ffPrstpol = dffrstpol;
+ }
+ if (dffcemux) {
+ ffPcemux = dffcemux;
+ ffPcepol = dffcepol;
+ }
+ sigP = dffQ;
+ }
+ }
+ }
+endcode
+
+// (10) If post-adder and PREG both present, match for a $mux cell driving
+// the 'C' input, where one of the $mux's inputs is the PREG output.
+// This indicates an accumulator situation, and one where a $mux exists
+// to override the accumulated value:
+// +--------------------------------+
+// | ____ |
+// +--| \ |
+// |$mux|-+ |
+// 'C' ---|____/ | |
+// | /-------\ +----+ |
+// +----+ +-| post- |___|PREG|---+ 'P'
+// |MREG|------ | adder | +----+
+// +----+ \-------/
+match postAddMux
+ if postAdd
+ if ffP
+ select postAddMux->type.in($mux)
+ select nusers(port(postAddMux, \Y)) == 2
+ choice <IdString> AB {\A, \B}
+ index <SigSpec> port(postAddMux, AB) === sigP
+ index <SigSpec> port(postAddMux, \Y) === sigC
+ set postAddMuxAB AB
+ optional
+endmatch
+
+code sigC
+ if (postAddMux)
+ sigC = port(postAddMux, postAddMuxAB == \A ? \B : \A);
+endcode
+
+code
+ accept;
+endcode
+
+// #######################
+
+// Subpattern for matching against input registers, based on knowledge of the
+// 'Q' input. Typically, identifying registers with clock-enable and reset
+// capability would be a task would be handled by other Yosys passes such as
+// dff2dffe, but since DSP inference happens much before this, these patterns
+// have to be manually identified.
+// At a high level:
+// (1) Starting from a $dff cell that (partially or fully) drives the given
+// 'Q' argument
+// (2) Match for a $mux cell implementing synchronous reset semantics ---
+// one that exclusively drives the 'D' input of the $dff, with one of its
+// $mux inputs being fully zero
+// (3) Match for a $mux cell implement clock enable semantics --- one that
+// exclusively drives the 'D' input of the $dff (or the other input of
+// the reset $mux) and where one of this $mux's inputs is connected to
+// the 'Q' output of the $dff
+subpattern in_dffe
+arg argD argQ clock
+
+code
+ dff = nullptr;
+ if (GetSize(argQ) == 0)
+ reject;
+ for (const auto &c : argQ.chunks()) {
+ // Abandon matches when 'Q' is a constant
+ if (!c.wire)
+ reject;
+ // Abandon matches when 'Q' has the keep attribute set
+ if (c.wire->get_bool_attribute(\keep))
+ reject;
+ // Abandon matches when 'Q' has a non-zero init attribute set
+ // (not supported by DSP48E1)
+ Const init = c.wire->attributes.at(\init, Const());
+ if (!init.empty())
+ for (auto b : init.extract(c.offset, c.width))
+ if (b != State::Sx && b != State::S0)
+ reject;
+ }
+endcode
+
+// (1) Starting from a $dff cell that (partially or fully) drives the given
+// 'Q' argument
+match ff
+ select ff->type.in($dff)
+ // 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
+
+ filter clock == SigBit() || port(ff, \CLK) == clock
+
+ set ffoffset offset
+endmatch
+
+code argQ argD
+ SigSpec Q = port(ff, \Q);
+ dff = ff;
+ dffclock = port(ff, \CLK);
+ dffD = argQ;
+ argD = port(ff, \D);
+ argQ = Q;
+ dffD.replace(argQ, argD);
+ // Only search for ffrstmux if dffD only
+ // has two (ff, ffrstmux) users
+ if (nusers(dffD) > 2)
+ argD = SigSpec();
+endcode
+
+// (2) Match for a $mux cell implementing synchronous reset semantics ---
+// exclusively drives the 'D' input of the $dff, with one of the $mux
+// inputs being fully zero
+match ffrstmux
+ if !argD.empty()
+ select ffrstmux->type.in($mux)
+ index <SigSpec> port(ffrstmux, \Y) === argD
+
+ choice <IdString> BA {\B, \A}
+ // DSP48E1 only supports reset to zero
+ select port(ffrstmux, BA).is_fully_zero()
+
+ define <bool> pol (BA == \B)
+ set ffrstpol pol
+ semioptional
+endmatch
+
+code argD
+ if (ffrstmux) {
+ dffrstmux = ffrstmux;
+ dffrstpol = ffrstpol;
+ argD = port(ffrstmux, ffrstpol ? \A : \B);
+ dffD.replace(port(ffrstmux, \Y), argD);
+
+ // Only search for ffcemux if argQ has at
+ // least 3 users (ff, <upstream>, ffrstmux) and
+ // dffD only has two (ff, ffrstmux)
+ if (!(nusers(argQ) >= 3 && nusers(dffD) == 2))
+ argD = SigSpec();
+ }
+ else
+ dffrstmux = nullptr;
+endcode
+
+// (3) Match for a $mux cell implement clock enable semantics --- one that
+// exclusively drives the 'D' input of the $dff (or the other input of
+// the reset $mux) and where one of this $mux's inputs is connected to
+// the 'Q' output of the $dff
+match ffcemux
+ if !argD.empty()
+ select ffcemux->type.in($mux)
+ index <SigSpec> port(ffcemux, \Y) === argD
+ choice <IdString> AB {\A, \B}
+ index <SigSpec> port(ffcemux, AB) === argQ
+ define <bool> pol (AB == \A)
+ set ffcepol pol
+ semioptional
+endmatch
+
+code argD
+ if (ffcemux) {
+ dffcemux = ffcemux;
+ dffcepol = ffcepol;
+ argD = port(ffcemux, ffcepol ? \B : \A);
+ dffD.replace(port(ffcemux, \Y), argD);
+ }
+ else
+ dffcemux = nullptr;
+endcode
+
+// #######################
+
+// Subpattern for matching against output registers, based on knowledge of the
+// 'D' input.
+// At a high level:
+// (1) Starting from an optional $mux cell that implements clock enable
+// semantics --- one where the given 'D' argument (partially or fully)
+// drives one of its two inputs
+// (2) Starting from, or continuing onto, another optional $mux cell that
+// implements synchronous reset semantics --- one where the given 'D'
+// argument (or the clock enable $mux output) drives one of its two inputs
+// and where the other input is fully zero
+// (3) Match for a $dff cell (whose 'D' input is the 'D' argument, or the
+// output of the previous clock enable or reset $mux cells)
+subpattern out_dffe
+arg argD argQ clock
+
+code
+ dff = nullptr;
+ for (auto c : argD.chunks())
+ // Abandon matches when 'D' has the keep attribute set
+ if (c.wire->get_bool_attribute(\keep))
+ reject;
+endcode
+
+// (1) Starting from an optional $mux cell that implements clock enable
+// semantics --- one where the given 'D' argument (partially or fully)
+// drives one of its two inputs
+match ffcemux
+ select ffcemux->type.in($mux)
+ // ffcemux output must have two users: ffcemux and ff.D
+ select nusers(port(ffcemux, \Y)) == 2
+
+ choice <IdString> AB {\A, \B}
+ // keep-last-value net must have at least three users: ffcemux, ff, downstream sink(s)
+ select nusers(port(ffcemux, AB)) >= 3
+
+ slice offset GetSize(port(ffcemux, \Y))
+ define <IdString> BA (AB == \A ? \B : \A)
+ index <SigBit> port(ffcemux, BA)[offset] === argD[0]
+
+ // Check that the rest of argD is present
+ filter GetSize(port(ffcemux, BA)) >= offset + GetSize(argD)
+ filter port(ffcemux, BA).extract(offset, GetSize(argD)) == argD
+
+ set ffoffset offset
+ define <bool> pol (AB == \A)
+ set ffcepol pol
+
+ semioptional
+endmatch
+
+code argD argQ
+ dffcemux = ffcemux;
+ if (ffcemux) {
+ SigSpec BA = port(ffcemux, ffcepol ? \B : \A);
+ SigSpec Y = port(ffcemux, \Y);
+ argQ = argD;
+ argD.replace(BA, Y);
+ argQ.replace(BA, port(ffcemux, ffcepol ? \A : \B));
+
+ dffcemux = ffcemux;
+ dffcepol = ffcepol;
+ }
+endcode
+
+// (2) Starting from, or continuing onto, another optional $mux cell that
+// implements synchronous reset semantics --- one where the given 'D'
+// argument (or the clock enable $mux output) drives one of its two inputs
+// and where the other input is fully zero
+match ffrstmux
+ select ffrstmux->type.in($mux)
+ // ffrstmux output must have two users: ffrstmux and ff.D
+ select nusers(port(ffrstmux, \Y)) == 2
+
+ choice <IdString> BA {\B, \A}
+ // DSP48E1 only supports reset to zero
+ select port(ffrstmux, BA).is_fully_zero()
+
+ slice offset GetSize(port(ffrstmux, \Y))
+ define <IdString> AB (BA == \B ? \A : \B)
+ index <SigBit> port(ffrstmux, AB)[offset] === argD[0]
+
+ // Check that offset is consistent
+ filter !ffcemux || ffoffset == offset
+ // Check that the rest of argD is present
+ filter GetSize(port(ffrstmux, AB)) >= offset + GetSize(argD)
+ filter port(ffrstmux, AB).extract(offset, GetSize(argD)) == argD
+
+ set ffoffset offset
+ define <bool> pol (AB == \A)
+ set ffrstpol pol
+
+ semioptional
+endmatch
+
+code argD argQ
+ dffrstmux = ffrstmux;
+ if (ffrstmux) {
+ SigSpec AB = port(ffrstmux, ffrstpol ? \A : \B);
+ SigSpec Y = port(ffrstmux, \Y);
+ argD.replace(AB, Y);
+
+ dffrstmux = ffrstmux;
+ dffrstpol = ffrstpol;
+ }
+endcode
+
+// (3) Match for a $dff cell (whose 'D' input is the 'D' argument, or the
+// output of the previous clock enable or reset $mux cells)
+match ff
+ select ff->type.in($dff)
+ // DSP48E1 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]
+
+ // Check that offset is consistent
+ filter (!ffcemux && !ffrstmux) || ffoffset == offset
+ // 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
+ // Check that FF.Q is connected to CE-mux
+ filter !ffcemux || port(ff, \Q).extract(offset, GetSize(argQ)) == argQ
+
+ filter clock == SigBit() || port(ff, \CLK) == clock
+
+ set ffoffset offset
+endmatch
+
+code argQ
+ SigSpec D = port(ff, \D);
+ SigSpec Q = port(ff, \Q);
+ if (!ffcemux) {
+ argQ = argD;
+ argQ.replace(D, Q);
+ }
+
+ // Abandon matches when 'Q' has a non-zero init attribute set
+ // (not supported by DSP48E1)
+ for (auto c : argQ.chunks()) {
+ Const init = c.wire->attributes.at(\init, Const());
+ if (!init.empty())
+ for (auto b : init.extract(c.offset, c.width))
+ if (b != State::Sx && b != State::S0)
+ reject;
+ }
+
+ dff = ff;
+ dffQ = argQ;
+ dffclock = port(ff, \CLK);
+endcode
projects / yosys.git / commitdiff