Implement sign extension LPM for BLIF target

tgt-blif/Makefile.in

@@ -44,7 +44,7 @@ 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 nex_data.o
+    lpm_ff.o lpm_mux.o lpm_part_vp.o lpm_re_logic.o lpm_sign_ext.o nex_data.o
 
 all: dep blif.tgt
 

tgt-blif/lpm.cc

@@ -108,6 +108,9 @@ int print_lpm(FILE*fd, ivl_lpm_t net)
 	  case IVL_LPM_SUB:
 	    rc += print_lpm_sub(fd, net);
 	    break;
+	  case IVL_LPM_SIGN_EXT:
+	    rc += print_lpm_sign_ext(fd, net);
+	    break;
 	  default:
 	    fprintf(fd, "# XXXX ivl_lpm_type(net) --> %d\n", ivl_lpm_type(net));
 	    fprintf(stderr, "%s:%u: sorry: ivl_lpm_type(net)==%d not implemented.\n",

tgt-blif/lpm_sign_ext.cc

@@ -0,0 +1,58 @@
+/*
+ * 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_SIGN_EXT devices
+ */
+int print_lpm_sign_ext(FILE*fd, ivl_lpm_t net)
+{
+      fprintf(fd, "# %s:%u: IVL_LPM_SIGN_EXT: width=%u\n",
+	      ivl_lpm_file(net), ivl_lpm_lineno(net), ivl_lpm_width(net));
+
+      ivl_nexus_t q_nex = ivl_lpm_q(net);
+      ivl_nexus_t d_nex = ivl_lpm_data(net,0);
+
+      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);
+
+      unsigned inw = d_ned->get_width();
+      unsigned outw = ivl_lpm_width(net);
+
+//printf("Shift: LPM width = %u, output width = %zd, input width = %u\n", outw, q_ned->get_width(), inw);
+
+      assert(outw == q_ned->get_width());
+      assert(inw < outw);
+
+      for (unsigned idx = 0 ; idx < outw ; idx += 1) {
+        unsigned idx_in = idx < inw ? idx : inw - 1;
+
+        fprintf(fd, ".names %s%s %s%s\n",
+                d_ned->get_name(), d_ned->get_name_index(idx_in),
+                q_ned->get_name(), q_ned->get_name_index(idx));
+        fprintf(fd, "1 1\n");
+      }
+
+      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_sign_ext(FILE*fd, ivl_lpm_t net);
 
 /*
  * Emit all the constants for a model. This works by scanning the