Merge pull request #11 from jakobj/feat/basic-adders

Add carry save adder

Author: rmanohar

math/Makefile

@@ -15,7 +15,7 @@
 # limitations under the License.
 # 
 #-------------------------------------------------------------------------
-TARGETACT=_all_.act fxp.act misc.act sint.act
+TARGETACT=_all_.act adders.act fxp.act misc.act sint.act
 TARGETACTSUBDIR=math
 
 include $(ACT_HOME)/scripts/Makefile.std

math/_all_.act

@@ -19,6 +19,7 @@
  **************************************************************************
  */
 
+import "math/adders.act";
 import "math/fxp.act";
 import "math/misc.act";
 import "math/sint.act";

math/adders.act

@@ -0,0 +1,41 @@
+/*************************************************************************
+ *
+ * This file is part of ACT standard library
+ *
+ * Copyright (c) 2025 Jakob Jordan
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ **************************************************************************
+ */
+
+namespace math {
+
+export
+template<pint N>
+defproc carry_save_adder(chan?(int<N>) a_in, b_in, c_in; chan!(int<N>) s_out, d_out) {
+ int<N> a, b, c;
+ int<1> s[N], d[N];
+ int<N> st, dt;
+
+ chp {
+ *[ a_in?a, b_in?b, c_in?c;
+ (, i : N : s[i] := (a{i} ^ b{i} ^ c{i}), d[i] := (a{i} & b{i} | ((a{i} ^ b{i}) & c{i})));
+ st := (| i : N : s[i] << i),
+ dt := (| i : N : d[i] << i);
+ s_out!st, d_out!(dt << 1)
+ ]
+ }
+}
+
+}