Implement barrel shifter LPM for BLIF target

tgt-blif/Makefile.in

@@ -44,7 +44,8 @@ CXXFLAGS = @WARNING_FLAGS@ @WARNING_FLAGS_CXX@ @CXXFLAGS@
 LDFLAGS = @LDFLAGS@
 
 O = blif.o constants.o logic_gate.o lpm.o lpm_add.o lpm_cmp_eq.o lpm_cmp_gt.o \
-    lpm_ff.o lpm_mux.o lpm_part_vp.o lpm_re_logic.o lpm_sign_ext.o nex_data.o
+    lpm_ff.o lpm_mux.o lpm_part_vp.o lpm_re_logic.o lpm_shift.o lpm_sign_ext.o \
+    nex_data.o
 
 all: dep blif.tgt
 

tgt-blif/lpm.cc

@@ -67,8 +67,9 @@ static int print_concat(FILE*fd, ivl_lpm_t net)
 int print_lpm(FILE*fd, ivl_lpm_t net)
 {
       int rc = 0;
+      ivl_lpm_type_t type = ivl_lpm_type(net);
 
-      switch (ivl_lpm_type(net)) {
+      switch (type) {
 	  case IVL_LPM_ADD:
 	    rc += print_lpm_add(fd, net);
 	    break;
@@ -108,6 +109,10 @@ int print_lpm(FILE*fd, ivl_lpm_t net)
 	  case IVL_LPM_SUB:
 	    rc += print_lpm_sub(fd, net);
 	    break;
+	  case IVL_LPM_SHIFTL:
+	  case IVL_LPM_SHIFTR:
+	    rc += print_lpm_shift(fd, net, type == IVL_LPM_SHIFTL);
+	    break;
 	  case IVL_LPM_SIGN_EXT:
 	    rc += print_lpm_sign_ext(fd, net);
 	    break;

tgt-blif/lpm_shift.cc

@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2016 Yury Gribov (tetra2005@gmail.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form under the terms of the GNU
+ *    General Public License as published by the Free Software
+ *    Foundation; either version 2 of the License, or (at your option)
+ *    any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+
+# include  "priv.h"
+# include  "nex_data.h"
+# include  <cassert>
+
+/*
+ * Implement IVL_LPM_SHIFT devices (via standard layered barrel shifter design)
+ */
+int print_lpm_shift(FILE*fd, ivl_lpm_t net, bool left)
+{
+      fprintf(fd, "# %s:%u: IVL_LPM_SHIFT%c: width=%u\n",
+	      ivl_lpm_file(net), ivl_lpm_lineno(net), left ? 'L' : 'R',
+	      ivl_lpm_width(net));
+
+      ivl_nexus_t q_nex = ivl_lpm_q(net);
+      ivl_nexus_t d_nex = ivl_lpm_data(net,0);
+      ivl_nexus_t s_nex = ivl_lpm_data(net,1);
+
+      blif_nex_data_t*q_ned = blif_nex_data_t::get_nex_data(q_nex);
+      blif_nex_data_t*d_ned = blif_nex_data_t::get_nex_data(d_nex);
+      blif_nex_data_t*s_ned = blif_nex_data_t::get_nex_data(s_nex);
+
+      unsigned dataw = ivl_lpm_width(net);
+      size_t shiftw = s_ned->get_width();
+      bool signed_ = ivl_lpm_signed(net);
+
+      assert(dataw == q_ned->get_width());
+      assert(dataw == d_ned->get_width());
+
+      // TODO: output width can be larger than data
+
+      // TODO: optimizations:
+      // * too large shift widths (more than data size)
+      // * shift width of 1
+      // * data width of 1
+
+      for (size_t lvl = 0 ; lvl < shiftw ; lvl += 1) {
+	    for (unsigned idx = 0 ; idx < dataw ; idx += 1) {
+		  unsigned idx_2 = left ? idx - (1 << lvl) : idx + (1 << lvl);
+		  bool borrow = idx_2 >= dataw;
+		  bool signed_borrow = borrow && !left && signed_;
+
+		  // First arg (shift)
+		  fprintf(fd, ".names %s%s",
+			  s_ned->get_name(), s_ned->get_name_index(lvl));
+
+		  // Multiplexed bits
+		  if (!borrow) {
+			if (lvl == 0) {
+			      fprintf(fd, " %s%s %s%s",
+				      d_ned->get_name(), d_ned->get_name_index(idx),
+				      d_ned->get_name(), d_ned->get_name_index(idx_2));
+			} else {
+			      fprintf(fd, " %s/%zu/%u %s/%zu/%u",
+				      q_ned->get_name(), lvl - 1, idx,
+				      q_ned->get_name(), lvl - 1, idx_2);
+			}
+		  } else if (signed_borrow) {
+			if (lvl == 0) {
+			      fprintf(fd, " %s%s %s%s",
+				      d_ned->get_name(), d_ned->get_name_index(idx),
+				      d_ned->get_name(), d_ned->get_name_index(dataw - 1));
+			} else {
+			      fprintf(fd, " %s/%zu/%u %s%s",
+				      q_ned->get_name(), lvl - 1, idx,
+				      d_ned->get_name(), d_ned->get_name_index(dataw - 1));
+			}
+		  } else {
+			if (lvl == 0) {
+			      fprintf(fd, " %s%s",
+				      d_ned->get_name(), d_ned->get_name_index(idx));
+			} else {
+			      fprintf(fd, " %s/%zu/%u",
+				      q_ned->get_name(), lvl - 1, idx);
+			}
+		  }
+
+		  // Output
+		  if (lvl == shiftw - 1) {
+			fprintf(fd, " %s%s\n",
+				q_ned->get_name(), q_ned->get_name_index(idx));
+		  } else {
+			fprintf(fd, " %s/%zu/%u\n",
+				q_ned->get_name(), lvl, idx);
+		  }
+
+		  if (!borrow || signed_borrow)
+			fputs("1-1 1\n"
+			      "01- 1\n",
+			      fd);
+		  else
+			fputs("01 1\n", fd);
+	    }
+      }
+
+      return 0;
+}
+

tgt-blif/priv.h

@@ -40,6 +40,7 @@ extern int print_lpm_cmp_ne(FILE*fd, ivl_lpm_t net);
 extern int print_lpm_mux(FILE*fd, ivl_lpm_t net);
 extern int print_lpm_part_vp(FILE*fd, ivl_lpm_t net);
 extern int print_lpm_re_logic(FILE*fd, ivl_lpm_t net);
+extern int print_lpm_shift(FILE*fd, ivl_lpm_t net, bool left);
 extern int print_lpm_sign_ext(FILE*fd, ivl_lpm_t net);
 
 /*