A5

A5/wires.h

@@ -0,0 +1,56 @@
+/*
+  Elementary functions for digital logic simulation
+
+  All functions declared here corresponds to wire connections.
+  No "real" computation is being carried out by them.
+
+  A single wire, when used as a control signal, is represented by the type 'bool'
+  Multiple wires, or a single wire not used as a control signal, is represented
+  by the type 'val'
+
+  For control signals (bools) you can use C built-in operators.
+*/
+
+#ifndef WIRES_H
+#define WIRES_H
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+// A generic bitvector - max 64 bits, though. By accident sufficient for our needs :-)
+typedef struct { uint64_t val; } val;
+
+// A pair of bitvectors - used by zip() and unzip()
+typedef struct {
+    val hi;
+    val lo;
+} hilo;
+
+// simple conversion
+val from_int(uint64_t);
+
+// unzip pairwise into two bitvectors holding even/odd bits
+hilo unzip(val);
+
+// zip a pair of bitvectors into one.
+val zip(hilo);
+
+// pick a set of bits from a value
+// lsb: index of least significant bit
+// sz: size
+val pick_bits(int lsb, int sz, val);
+
+// put sz least significant bits from val at position lsb in result.
+// rest of result is 0.
+val put_bits(int lsb, int sz, val);
+
+// pick a single bit from a value
+bool pick_one(int position, val);
+
+// reverse the order of bytes within value
+val reverse_bytes(int num_bytes, val value);
+
+// sign extend by copying a sign bit to all higher positions
+val sign_extend(int sign_position, val value);
+
+#endif