diff --git a/tgt-blif/Makefile.in b/tgt-blif/Makefile.in index 4cc7c0c27..57acc083d 100644 --- a/tgt-blif/Makefile.in +++ b/tgt-blif/Makefile.in @@ -44,7 +44,7 @@ CPPFLAGS = $(INCLUDE_PATH) @CPPFLAGS@ @DEFS@ @PICFLAG@ CXXFLAGS = @WARNING_FLAGS@ @CXXFLAGS@ LDFLAGS = @LDFLAGS@ -O = blif.o constants.o logic_gate.o lpm.o nex_data.o +O = blif.o constants.o logic_gate.o lpm.o lpm_add.o nex_data.o all: dep blif.tgt diff --git a/tgt-blif/lpm.cc b/tgt-blif/lpm.cc index 72ec6aedc..e9a616bf1 100644 --- a/tgt-blif/lpm.cc +++ b/tgt-blif/lpm.cc @@ -100,6 +100,9 @@ int print_lpm(FILE*fd, ivl_lpm_t net) int rc = 0; switch (ivl_lpm_type(net)) { + case IVL_LPM_ADD: + rc += print_lpm_add(fd, net); + break; case IVL_LPM_CONCAT: case IVL_LPM_CONCATZ: rc += print_concat(fd, net); diff --git a/tgt-blif/lpm_add.cc b/tgt-blif/lpm_add.cc new file mode 100644 index 000000000..0b70cbb73 --- /dev/null +++ b/tgt-blif/lpm_add.cc @@ -0,0 +1,96 @@ +/* + * Copyright (c) 2013 Stephen Williams (steve@icarus.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 + +/* + * assign Q = A ^ B ^ Cin; + * assign Cout = A&B | A&Cin | B&Cin; + */ +int print_lpm_add(FILE*fd, ivl_lpm_t net) +{ + fprintf(fd, "# %s:%u: IVL_LPM_ADD: 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 a_nex = ivl_lpm_data(net,0); + ivl_nexus_t b_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*a_ned = blif_nex_data_t::get_nex_data(a_nex); + blif_nex_data_t*b_ned = blif_nex_data_t::get_nex_data(b_nex); + + assert(ivl_lpm_width(net) == q_ned->get_width()); + assert(ivl_lpm_width(net) == a_ned->get_width()); + assert(ivl_lpm_width(net) == b_ned->get_width()); + + // Q[0] = A[0] ^ B[0] + fprintf(fd, ".names %s%s %s%s %s%s\n" + "10 1\n" + "01 1\n", + a_ned->get_name(), a_ned->get_name_index(0), + b_ned->get_name(), b_ned->get_name_index(0), + q_ned->get_name(), q_ned->get_name_index(0)); + + // Special case: If this is a 1-bit adder, then all we need is + // the XOR above. We're done. + if (ivl_lpm_width(net) == 1) + return 0; + + // Cout[0] = A[0] & B[0] + fprintf(fd, ".names %s%s %s%s %s%s/cout\n" + "11 1\n", + a_ned->get_name(), a_ned->get_name_index(0), + b_ned->get_name(), b_ned->get_name_index(0), + q_ned->get_name(), q_ned->get_name_index(0)); + + for (unsigned idx = 1 ; idx < ivl_lpm_width(net) ; idx += 1) { + char cin[128]; + snprintf(cin, sizeof cin, "%s%s/cout", + q_ned->get_name(), q_ned->get_name_index(idx-1)); + + // Q[idx] = A[idx] ^ B[idx] ^ cin + fprintf(fd, ".names %s%s %s%s %s %s%s\n" + "001 1\n" + "010 1\n" + "100 1\n" + "111 1\n", + a_ned->get_name(), a_ned->get_name_index(idx), + b_ned->get_name(), b_ned->get_name_index(idx), + cin, + q_ned->get_name(), q_ned->get_name_index(idx)); + + if ((idx+1) == ivl_lpm_width(net)) + continue; + + // Cout[idx] = A[idx]&B[idx] | A[idx]&Cin | B[idx]&Cin + fprintf(fd, ".names %s%s %s%s %s %s%s/cout\n" + "011 1\n" + "101 1\n" + "11- 1\n", + a_ned->get_name(), a_ned->get_name_index(idx), + b_ned->get_name(), b_ned->get_name_index(idx), + cin, + q_ned->get_name(), q_ned->get_name_index(idx)); + } + + return 0; +} diff --git a/tgt-blif/priv.h b/tgt-blif/priv.h index 55a765a71..2cc3812ff 100644 --- a/tgt-blif/priv.h +++ b/tgt-blif/priv.h @@ -31,6 +31,7 @@ extern int blif_errors; extern int print_logic_gate(FILE*fd, ivl_net_logic_t net); extern int print_lpm(FILE*fd, ivl_lpm_t net); +extern int print_lpm_add(FILE*fd, ivl_lpm_t net); /* * Emit all the constants for a model. This works by scanning the