Add signed 64-bit integer support.

src/UInt64.c

@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2022-2023 Jordan Bancino <@jordan:bancino.net>
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <UInt64.h>
+
+#include <stddef.h>
+#include <signal.h>
+
+size_t
+UInt64Str(UInt64 x, int base, char *out, size_t len)
+{
+    static const char symbols[] = "0123456789ABCDEF";
+
+    size_t i = len - 1;
+    size_t j = 0;
+
+    UInt64 base64 = UInt64Create(0, base);
+
+    /* We only have symbols up to base 16 */
+    if (base < 2 || base > 16)
+    {
+        return 0;
+    }
+
+    do
+    {
+        UInt64 mod = UInt64Rem(x, base64);
+        UInt32 low = UInt64Low(mod);
+
+        out[i] = symbols[low];
+        i--;
+        x = UInt64Div(x, base64);
+    } while (UInt64Gt(x, UInt64Create(0, 0)));
+
+    while (++i < len)
+    {
+        out[j++] = out[i];
+    }
+
+    out[j] = '\0';
+
+    return j;
+}
+
+#ifndef UINT64_NATIVE
+
+/* No native 64-bit support, add our own */
+
+UInt64
+UInt64Create(UInt32 high, UInt32 low)
+{
+    UInt64 x;
+
+    x.i[0] = low;
+    x.i[1] = high;
+
+    return x;
+}
+
+UInt64
+UInt64Add(UInt64 x, UInt64 y)
+{
+    UInt64 z = UInt64Create(0, 0);
+    int carry;
+
+    z.i[0] = x.i[0] + y.i[0];
+    carry = z.i[0] < x.i[0];
+    z.i[1] = x.i[1] + y.i[1] + carry;
+
+    return z;
+}
+
+UInt64
+UInt64Sub(UInt64 x, UInt64 y)
+{
+    UInt64 twosCompl = UInt64Add(UInt64Not(y), UInt64Create(0, 1));
+
+    return UInt64Add(x, twosCompl);
+}
+
+UInt64
+UInt64Mul(UInt64 x, UInt64 y)
+{
+    UInt64 z = UInt64Create(0, 0);
+
+    /* while (y > 0) */
+    while (UInt64Gt(y, UInt64Create(0, 0)))
+    {
+        /* if (y & 1 != 0) */
+        if (UInt64Neq(UInt64And(y, UInt64Create(0, 1)), UInt64Create(0, 0)))
+        {
+            z = UInt64Add(z, x);
+        }
+
+        x = UInt64Sll(x, 1);
+        y = UInt64Srl(y, 1);
+    }
+
+    return z;
+}
+
+typedef struct
+{
+    UInt64 q;
+    UInt64 r;
+} UInt64Ldiv;
+
+static UInt64Ldiv
+UInt64LongDivision(UInt64 n, UInt64 d)
+{
+    UInt64Ldiv o;
+
+    int i;
+
+    o.q = UInt64Create(0, 0);
+    o.r = UInt64Create(0, 0);
+
+    if (UInt64Eq(d, UInt64Create(0, 0)))
+    {
+        raise(SIGFPE);
+        return o;
+    }
+
+    for (i = 63; i >= 0; i--)
+    {
+        UInt64 bit = UInt64And(UInt64Srl(n, i), UInt64Create(0, 1));
+        o.r = UInt64Sll(o.r, 1);
+        o.r = UInt64Or(o.r, bit);
+
+        if (UInt64Geq(o.r, d))
+        {
+            o.r = UInt64Sub(o.r, d);
+            o.q = UInt64Or(o.q, UInt64Sll(UInt64Create(0, 1), i));
+        }
+    }
+
+    return o;
+}
+
+UInt64
+UInt64Div(UInt64 x, UInt64 y)
+{
+    return UInt64LongDivision(x, y).q;
+}
+
+UInt64
+UInt64Rem(UInt64 x, UInt64 y)
+{
+    return UInt64LongDivision(x, y).r;
+}
+
+UInt64
+UInt64Sll(UInt64 x, int y)
+{
+    UInt64 z;
+
+    if (!y)
+    {
+        return x;
+    }
+
+    z = UInt64Create(0, 0);
+
+    if (y < 32)
+    {
+        z.i[1] = (x.i[0] >> (32 - y)) | (x.i[1] << y);
+        z.i[0] = x.i[0] << y;
+    }
+    else
+    {
+        z.i[1] = x.i[0] << (y - 32);
+    }
+
+    return z;
+}
+
+UInt64
+UInt64Srl(UInt64 x, int y)
+{
+    UInt64 z;
+
+    if (!y)
+    {
+        return x;
+    }
+
+    z = UInt64Create(0, 0);
+
+    if (y < 32)
+    {
+        z.i[0] = (x.i[1] << (32 - y)) | (x.i[0] >> y);
+        z.i[1] = x.i[1] >> y;
+    }
+    else
+    {
+        z.i[0] = x.i[1] >> (y - 32);
+    }
+
+    return z;
+}
+
+UInt64
+UInt64And(UInt64 x, UInt64 y)
+{
+    return UInt64Create(x.i[1] & y.i[1], x.i[0] & y.i[0]);
+}
+
+UInt64
+UInt64Or(UInt64 x, UInt64 y)
+{
+    return UInt64Create(x.i[1] | y.i[1], x.i[0] | y.i[0]);
+}
+
+UInt64
+UInt64Xor(UInt64 x, UInt64 y)
+{
+    return UInt64Create(x.i[1] ^ y.i[1], x.i[0] ^ y.i[0]);
+}
+
+UInt64
+UInt64Not(UInt64 x)
+{
+    return UInt64Create(~(x.i[1]), ~(x.i[0]));
+}
+
+int
+UInt64Eq(UInt64 x, UInt64 y)
+{
+    return x.i[0] == y.i[0] && x.i[1] == y.i[1];
+}
+
+int
+UInt64Lt(UInt64 x, UInt64 y)
+{
+    return x.i[1] < y.i[1] || (x.i[1] == y.i[1] && x.i[0] < y.i[0]);
+}
+
+int
+UInt64Gt(UInt64 x, UInt64 y)
+{
+    return x.i[1] > y.i[1] || (x.i[1] == y.i[1] && x.i[0] > y.i[0]);
+}
+
+#endif