Implement "M" parameter for Spice

This implementation is pretty simplistic and
applies "M" the following way:
* R: R(final) = R/M
* L: L(final) = L/M
* C: C(final) = C*M
* M: W(final) = W*M
* D: A(final) = A*M
* Q: AE(final) = AE*M

The other parameters (specifically the other
geometry parameters) are not scaled yet.

src/db/db/dbNetlistSpiceReader.cc

@@ -85,34 +85,73 @@ static db::DeviceClass *make_device_class (db::Circuit *circuit, const std::stri
   return cls;
 }
 
-bool NetlistSpiceReaderDelegate::element (db::Circuit *circuit, const std::string &element, const std::string &name, const std::string &model, double value, const std::vector<db::Net *> &nets, const std::map<std::string, double> &params)
+bool NetlistSpiceReaderDelegate::element (db::Circuit *circuit, const std::string &element, const std::string &name, const std::string &model, double value, const std::vector<db::Net *> &nets, const std::map<std::string, double> &pv)
 {
+  std::map<std::string, double> params = pv;
+
+  double mult = 1.0;
+  std::map<std::string, double>::const_iterator mp = params.find ("M");
+  if (mp != params.end ()) {
+    mult = mp->second;
+  }
+
+  if (mult < 1e-10) {
+    error (tl::sprintf (tl::to_string (tr ("Invalid multiplier value (M=%.12g) - must not be zero or negative")), mult));
+  }
+
   std::string cn = model;
   db::DeviceClass *cls = circuit->netlist ()->device_class_by_name (cn);
 
   if (cls) {
+
     //  use given class
+
   } else if (element == "R") {
+
     if (cn.empty ()) {
       cn = "RES";
     }
     cls = make_device_class<db::DeviceClassResistor> (circuit, cn);
+
+    //  Apply multiplier
+    value /= mult;
+
   } else if (element == "L") {
+
     if (cn.empty ()) {
       cn = "IND";
     }
     cls = make_device_class<db::DeviceClassInductor> (circuit, cn);
+
+    //  Apply multiplier
+    value /= mult;
+
   } else if (element == "C") {
+
     if (cn.empty ()) {
       cn = "CAP";
     }
     cls = make_device_class<db::DeviceClassCapacitor> (circuit, cn);
+
+    //  Apply multiplier
+    value *= mult;
+
   } else if (element == "D") {
+
     if (cn.empty ()) {
       cn = "DIODE";
     }
     cls = make_device_class<db::DeviceClassDiode> (circuit, cn);
+
+    //  Apply multiplier to "A"
+    std::map<std::string, double>::iterator p;
+    p = params.find ("A");
+    if (p != params.end ()) {
+      p->second *= mult;
+    }
+
   } else if (element == "Q") {
+
     if (nets.size () == 3) {
       if (cn.empty ()) {
         cn = "BJT3";
@@ -126,12 +165,29 @@ bool NetlistSpiceReaderDelegate::element (db::Circuit *circuit, const std::strin
     } else {
       error (tl::to_string (tr ("'Q' element needs to have 3 or 4 terminals")));
     }
+
+    //  Apply multiplier to "AE"
+    std::map<std::string, double>::iterator p;
+    p = params.find ("AE");
+    if (p != params.end ()) {
+      p->second *= mult;
+    }
+
   } else if (element == "M") {
+
     if (nets.size () == 4) {
       if (cn.empty ()) {
         cn = "MOS4";
       }
       cls = make_device_class<db::DeviceClassMOS4Transistor> (circuit, cn);
+
+      //  Apply multiplier to "W"
+      std::map<std::string, double>::iterator p;
+      p = params.find ("W");
+      if (p != params.end ()) {
+        p->second *= mult;
+      }
+
     } else {
       error (tl::to_string (tr ("'M' element needs to have 4 terminals")));
     }

src/db/unit_tests/dbNetlistReaderTests.cc

@@ -333,3 +333,29 @@ TEST(8_Include)
   );
 }
 
+TEST(9_DeviceMultipliers)
+{
+  db::Netlist nl;
+
+  std::string path = tl::combine_path (tl::combine_path (tl::combine_path (tl::testsrc (), "testdata"), "algo"), "nreader9.cir");
+
+  db::NetlistSpiceReader reader;
+  tl::InputStream is (path);
+  reader.read (is, nl);
+
+  EXPECT_EQ (nl.to_string (),
+    "circuit .TOP ();\n"
+    "  device RES $1 (A='1',B='2') (R=850,L=0,W=0,A=0,P=0);\n"
+    "  device RES $2 (A='3',B='4') (R=1700,L=0,W=0,A=0,P=0);\n"
+    "  device NMOS $1 (S='1',G='2',D='3',B='4') (L=7,W=4,AS=0,AD=0,PS=0,PD=0);\n"
+    "  device PMOS $2 (S='1',G='2',D='3',B='4') (L=7,W=2,AS=0,AD=0,PS=0,PD=0);\n"
+    "  device CAP $1 (A='1',B='2') (C=2e-09,A=0,P=0);\n"
+    "  device CAP $2 (A='3',B='4') (C=1e-09,A=0,P=0);\n"
+    "  device DIODE $1 (A='1',C='2') (A=20,P=0);\n"
+    "  device DIODE $2 (A='3',C='4') (A=10,P=0);\n"
+    "  device BIP $1 (C='1',B='2',E='3',S='4') (AE=20,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
+    "  device BIP $2 (C='1',B='2',E='3',S='4') (AE=10,PE=0,AB=0,PB=0,AC=0,PC=0,NE=1);\n"
+    "end;\n"
+  );
+}
+

testdata/algo/nreader9.cir

@@ -0,0 +1,12 @@
+
+R$1 1 2 1.7k M=2
+R$2 3 4 1.7k
+M$1 1 2 3 4 NMOS W=2u L=7u M=2
+M$2 1 2 3 4 PMOS W=2u L=7u 
+C$1 1 2 1e-9 M=2 
+C$2 3 4 1e-9 
+D$1 1 2 DIODE A=10P M=2 
+D$2 3 4 DIODE A=10P
+Q$1 1 2 3 4 BIP AE=10P M=2 
+Q$2 1 2 3 4 BIP AE=10P
+