A5

A5/wires.c

@@ -0,0 +1,98 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "wires.h"
+
+hilo unzip(val value) {
+    uint64_t hi, lo, val;
+    val = value.val;
+    hi = lo = 0;
+    for (int i=0; i<32; i++) {
+	lo |= (val & 1) << i;
+	val >>= 1;
+	hi |= (val & 1) << i;
+	val >>= 1;
+    }
+    hilo result;
+    result.hi = from_int(hi);
+    result.lo = from_int(lo);
+    return result;
+}
+
+val zip(hilo values) {
+    uint64_t hi = values.hi.val;
+    uint64_t lo = values.lo.val;
+    uint64_t result = 0;
+    for (int i=0; i<32; i++) {
+	result |= (hi & 1) << (2*i+1);
+	hi >>= 1;
+	result |= (lo & 1) << (2*i);
+	lo >>= 1;
+    }
+    return from_int(result);
+}
+
+val pick_bits(int lsb, int sz, val value) {
+    uint64_t v = value.val;
+    v >>= lsb;
+    if (sz < 64) {
+        uint64_t mask = 1;
+        mask <<= sz;
+        mask -= 1;
+        v &= mask;
+    }
+    return from_int(v);
+}
+
+val put_bits(int lsb, int sz, val value) {
+    val masked = pick_bits(0,sz,value);
+    masked.val <<= lsb;
+    return masked;
+}
+
+val pick_bits_arr(int msb, int sz, val arr[]) {
+    if (sz > 64) {
+        fprintf(stderr, "error: pick_bits_arr called with sz > 64");
+        exit(EXIT_FAILURE);
+    }
+
+    int offset = msb % 8;
+    int start_byte = msb / 8;
+    int covered_bytes = sz / 8;
+
+    uint64_t retval = 0;
+    for(int i = start_byte; i < covered_bytes; i++) {
+        retval += ((uint64_t) (arr[i].val)) >> (offset + i * 8);
+    }
+
+    uint64_t mask = ((uint64_t)-1) >> (64 - offset);
+    retval &= mask;
+    return from_int(retval);
+}
+
+
+bool pick_one(int position, val value) {
+  return ((value.val >> position) & 1) == 1;
+}
+
+val from_int(uint64_t v) {
+    val val;
+    val.val = v;
+    return val;
+}
+
+val reverse_bytes(int num_bytes, val value) {
+    uint64_t val = value.val;
+    uint64_t res = 0;
+    while (num_bytes--) {
+        res <<= 8;
+        res |= val & 0xFF;
+        val >>= 8;
+    }
+    return from_int(res);
+}
+
+val sign_extend(int sign_position, val value) {
+    uint64_t sign = value.val & (((uint64_t)1) << sign_position);
+    return from_int(value.val - (sign << 1));
+}
+