Add 64-bit emulation for platforms that don't have a native 64-bit type.

src/Int64.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 <Int64.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

src/include/Int.h

@@ -55,10 +55,9 @@
 
 #include <limits.h>
 
-#define BIT64_MAX 18446744073709551615
+#define BIT32_MAX 4294967295UL
-#define BIT32_MAX 4294967295
+#define BIT16_MAX 65535UL
-#define BIT16_MAX 65535
+#define BIT8_MAX 255UL
-#define BIT8_MAX 255
 
 #ifndef UCHAR_MAX
 #error Size of char data type is unknown. Define UCHAR_MAX.
@@ -120,6 +119,4 @@ typedef unsigned char UInt32;
 #error Unable to determine suitable data type for 32-bit integers.
 #endif
 
-/* The ANSI C standard only guarantees a data size of up to 32 bits. */
+#endif /* CYTOPLASM_INT_H */
-
-#endif

src/include/Int64.h

@@ -0,0 +1,249 @@
+/*
+ * 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.
+ */
+#ifndef CYTOPLASM_INT64_H
+#define CYTOPLASM_INT64_H
+
+/***
+ * @Nm Int64
+ * @Nd Fixed-width 64 bit integers.
+ * @Dd August 11, 2023
+ *
+ * .Pp
+ * ANSI C89 (or C99 for that matter) provides no required mechanism
+ * for 64 bit integers. Nevertheless, many compilers provide them as
+ * extensions. However, since it is not a gaurantee, and to be fully
+ * standards-compliant and thus portable, a platform-agnostic interface
+ * is required. This header provides such an interface. If the platform
+ * has a 64 bit integer type, that is used, and native operations are
+ * performed by C preprocessor macro expansion. Otherwise, a
+ * compatibility layer is provided, which implements 64-bit
+ * arithmetic on an array of 2 32-bit numbers which are provided by
+ * .Xr Int 3 .
+ * .Pp
+ * Note that 64-bit emulation is certainly not as performant as using
+ * native 64-bit operations, so whenever possible, the native
+ * operations should be preferred. However, since C provides no required
+ * 64 bit integer on 32-bit and less platforms, this API can be used as
+ * a "good enough" fallback mechanism.
+ * .Pp
+ * Also note that this implementation, both in the native and
+ * non-native forms, makes some assumptions:
+ * .Bl -bullet -width Ds
+ * .It
+ * When a cast from a larger integer to a smaller integer is performed,
+ * the upper bits are truncated, not the lower bits.
+ * .It
+ * Negative numbers are represented in memory and in registers in two's
+ * compliment form.
+ * .El
+ * .Pp
+ * This API may provide unexpected output if these assumptions are
+ * false for a given platform.
+ *
+ * @ignore-typedefs
+ */
+
+#include <Int.h>
+
+#include <stddef.h>
+
+#define BIT64_MAX 18446744073709551615UL
+
+/* TODO: Implement signed arithmetic */
+
+#if UINT_MAX == BIT64_MAX
+/* typedef signed int Int64; */
+typedef unsigned int UInt64;
+
+#define UINT64_NATIVE
+
+#elif ULONG_MAX == BIT64_MAX
+/* typedef signed int Int64; */
+typedef unsigned long UInt64;
+
+#define UINT64_NATIVE
+
+#endif
+
+#ifdef UINT64_NATIVE
+
+#define UInt64Create(high, low) (((UInt64) (high) << 32) | (low))
+#define UInt64Low(a) ((UInt32) ((a) & 0x00000000FFFFFFFF))
+#define UInt64High(a) ((UInt32) ((a) >> 32))
+
+#define UInt64Add(a, b) ((a) + (b))
+#define UInt64Sub(a, b) ((a) - (b))
+#define UInt64Mul(a, b) ((a) * (b))
+#define UInt64Div(a, b) ((a) / (b))
+#define UInt64Rem(a, b) ((a) % (b))
+
+#define UInt64Bsl(a, b) ((a) << (b))
+#define UInt64Bsr(a, b) ((a) >> (b))
+
+#define UInt64And(a, b) ((a) & (b))
+#define UInt64Or(a, b) ((a) | (b))
+#define UInt64Xor(a, b) ((a) ^ (b))
+#define UInt64Not(a) (~(a))
+
+#define UInt64Eq(a, b) ((a) == (b))
+#define UInt64Lt(a, b) ((a) < (b))
+#define UInt64Gt(a, b) ((a) > (b))
+
+#define UInt64Neq(a, b) ((a) != (b))
+#define UInt64Leq(a, b) ((a) <= (b))
+#define UInt64Geq(a, b) ((a) >= (b))
+
+#else
+
+/**
+ * For platforms that do not have a native integer large enough to
+ * store a 64 bit integer, this struct is used. i[0] contains the low
+ * bits of integer, and i[1] contains the high bits of the integer.
+ * .Pp
+ * This struct should not be accessed directly, because UInt64 may not
+ * actually be this struct, it might be an actual integer type. For
+ * maximum portability, only use the functions defined here to
+ * manipulate 64 bit integers.
+ */
+typedef struct
+{
+    UInt32 i[2];
+} UInt64;
+
+/**
+ * Create a new unsigned 64 bit integer using the given high and low
+ * bits.
+ */
+extern UInt64 UInt64Create(UInt32, UInt32);
+
+/**
+ * Add two unsigned 64 bit integers together.
+ */
+extern UInt64 UInt64Add(UInt64, UInt64);
+
+/**
+ * Subtract the second 64 bit integer from the first.
+ */
+extern UInt64 UInt64Sub(UInt64, UInt64);
+
+/**
+ * Multiply two 64 bit integers together. The non-native version of
+ * this function uses the Russian Peasant method of multiplication,
+ * which should afford more performance than a naive multiplication by
+ * addition, but it is still rather slow and depends on the size of
+ * the integers being multiplied.
+ */
+extern UInt64 UInt64Mul(UInt64, UInt64);
+
+/**
+ * Divide the first 64 bit integer by the second and return the
+ * quotient. The non-native version of this function uses naive binary
+ * long division, which is slow, but gauranteed to finish in constant
+ * time.
+ */
+extern UInt64 UInt64Div(UInt64, UInt64);
+
+/**
+ * Divide the first 64 bit integer by the second and return the
+ * remainder. The non-native version of this function uses naive binary
+ * long division, which is slow, but gauranteed to finish in constant
+ * time.
+ */
+extern UInt64 UInt64Rem(UInt64, UInt64);
+
+/**
+ * Perform a left logical bit shift of a 64 bit integer. The second
+ * parameter is how many places to shift, and is declared as a regular
+ * integer because anything more than 64 does not make sense.
+ */
+extern UInt64 UInt64Sll(UInt64, int);
+
+/**
+ * Perform a right logical bit shift of a 64 bit integer. The second
+ * parameter is how many places to shift, and is declared as a regular
+ * integer because anything more than 64 does not make sense.
+ */
+extern UInt64 UInt64Srl(UInt64, int);
+
+/**
+ * Perform a bitwise AND (&) of the provided 64 bit integers.
+ */
+extern UInt64 UInt64And(UInt64, UInt64);
+
+/**
+ * Perform a bitwise OR (|) of the provided 64 bit integers.
+ */
+extern UInt64 UInt64Or(UInt64, UInt64);
+
+/**
+ * Perform a bitwise XOR (^) of the provided 64 bit integers.
+ */
+extern UInt64 UInt64Xor(UInt64, UInt64);
+
+/**
+ * Perform a bitwise NOT (~) of the provided 64 bit integer.
+ */
+extern UInt64 UInt64Not(UInt64);
+
+/**
+ * Perform a comparison of the provided 64 bit integers and return a C
+ * boolean that is true if and only if they are equal.
+extern int UInt64Eq(UInt64, UInt64);
+
+/**
+ * Perform a comparison of the provided 64 bit integers and return a C
+ * boolean that is true if and only if the second operand is strictly
+ * less than the first.
+ */
+extern int UInt64Lt(UInt64, UInt64);
+
+/**
+ * Perform a comparison of the provided 64 bit integers and return a C
+ * boolean that is true if and only if the second operand is strictly
+ * greater than the first.
+ */
+extern int UInt64Gt(UInt64, UInt64);
+
+#define UInt64Low(a) ((a).i[0])
+#define UInt64High(a) ((a).i[1])
+
+#define UInt64Neq(a, b) (!UInt64Eq(a, b))
+#define UInt64Leq(a, b) (UInt64Eq(a, b) || UInt64Lt(a, b))
+#define UInt64Geq(a, b) (UInt64Eq(a, b) || UInt64Gt(a, b))
+
+#endif
+
+#define UINT64_STRBUF 65 /* Base 2 representation with '\0' */
+
+/**
+ * Convert a 64 bit integer to a string in an arbitrary base
+ * representation specified by the second parameter, using the provided
+ * buffer and length specified by the third and fourth parameters. To
+ * guarantee that the string will fit in the buffer, allocate it of
+ * size UINT64_STRBUF or larger. Note that a buffer size smaller than
+ * UINT64_STRBUF will invoke undefined behavior.
+ */
+extern size_t UInt64Str(UInt64, int, char *, size_t);
+
+#endif /* CYTOPLASM_INT64_H */

tools/int64.c

@@ -0,0 +1,117 @@
+#include <Int64.h>
+
+#include <Log.h>
+
+/* AssertEquals(actual, expected) */
+int AssertEquals(char *msg, UInt64 x, UInt64 y)
+{
+    if (!UInt64Eq(x, y))
+    {
+        Log(LOG_ERR, "%s: Expected 0x%X 0x%X, got 0x%X 0x%X", msg,
+            UInt64High(y), UInt64Low(y),
+            UInt64High(x), UInt64Low(x));
+
+        return 0;
+    }
+
+    return 1;
+}
+
+int Main(void)
+{
+	UInt64 x, y;
+
+    Log(LOG_INFO, "sizeof(UInt64) = %lu", sizeof(UInt64));
+
+#ifdef UINT64_NATIVE
+    Log(LOG_INFO, "Using native 64-bit integers.");
+#else
+    Log(LOG_INFO, "Using emulated 64-bit integers.");
+#endif
+
+    /* BSR Tests */
+
+	x = UInt64Create(0x000000FF, 0x00000000);
+
+	y = UInt64Bsr(x, 4);
+    AssertEquals("x >> 4", y, UInt64Create(0x0000000F, 0xF0000000));
+
+    y = UInt64Bsr(x, 8);
+    AssertEquals("x >> 8", y, UInt64Create(0x00000000, 0xFF000000));
+
+    y = UInt64Bsr(x, 36);
+    AssertEquals("x >> 36", y, UInt64Create(0x00000000, 0x0000000F));
+
+    /* BSL Tests */
+
+    x = UInt64Create(0x00000000, 0xFF000000);
+
+    y = UInt64Bsl(x, 4);
+    AssertEquals("x << 4", y, UInt64Create(0x0000000F, 0xF0000000));
+
+    y = UInt64Bsl(x, 8);
+    AssertEquals("x << 8", y, UInt64Create(0x000000FF, 0x00000000));
+
+    y = UInt64Bsl(x, 36);
+    AssertEquals("x << 36", y, UInt64Create(0xF0000000, 0x00000000));
+
+    /* ADD Tests */
+
+    x = UInt64Create(0x00000000, 0xF0000001);
+    y = UInt64Create(0x00000000, 0x00000002);
+    AssertEquals("0xF0000001 + 0x00000002", UInt64Add(x, y), UInt64Create(0x00000000, 0xF0000003));
+
+    x = UInt64Create(0x00000000, 0xF0000000);
+    y = UInt64Create(0x00000000, 0x10000000);
+    AssertEquals("0xF0000000 + 0x10000000", UInt64Add(x, y), UInt64Create(0x00000001, 0x00000000));
+
+    /* SUB Tests */
+    x = UInt64Create(0x00000000, 0x00000005);
+    y = UInt64Create(0x00000000, 0x00000002);
+    AssertEquals("0x00000005 - 0x00000002", UInt64Sub(x, y), UInt64Create(0x00000000, 0x00000003));
+
+    x = UInt64Create(0x00000001, 0x00000000);
+    y = UInt64Create(0x00000000, 0x00000001);
+    AssertEquals("0x00000001 0x00000000 - 0x00000001", UInt64Sub(x, y), UInt64Create(0x00000000, 0xFFFFFFFF));
+
+    /* MUL Tests */
+    x = UInt64Create(0, 18);
+    y = UInt64Create(0, 1);
+    AssertEquals("18 * 1", UInt64Mul(x, y), UInt64Create(0, 18));
+
+    x = UInt64Create(0, 20);
+    y = UInt64Create(0, 12);
+    AssertEquals("20 * 12", UInt64Mul(x, y), UInt64Create(0, 240));
+
+    x = UInt64Create(0x00000000, 0x00000005);
+    y = UInt64Create(0x00000000, 0x00000005);
+    AssertEquals("0x00000005 * 0x00000005", UInt64Mul(x, y), UInt64Create(0x00000000, 0x00000019));
+
+    x = UInt64Create(0x00000001, 0x00000000);
+    y = UInt64Create(0x00000000, 0x00000005);
+    AssertEquals("0x00000001 0x00000000 * 0x00000005", UInt64Mul(x, y), UInt64Create(0x00000005, 0x00000000));
+
+    /* DIV Tests */
+    x = UInt64Create(0, 12);
+    y = UInt64Create(0, 4);
+    AssertEquals("12 / 4", UInt64Div(x, y), UInt64Create(0, 3));
+
+    /* MOD Tests */
+    x = UInt64Create(0x000000FF, 0x00000000);
+    y = UInt64Create(0x00000000, 0x00000010);
+    AssertEquals("0x000000FF 0x00000000 mod 0x00000010", UInt64Rem(x, y), UInt64Create(0, 0));
+
+    x = UInt64Create(0x00000000, 0xFF000000);
+    y = UInt64Create(0x00000000, 0x00000010);
+    AssertEquals("0x00000000 0xFF000000 mod 0x00000010", UInt64Rem(x, y), UInt64Create(0, 0));
+
+    x = UInt64Create(0xFF000000, 0x00000000);
+    y = UInt64Create(0x00000000, 0x00000010);
+    AssertEquals("0xFF000000 0x00000000 mod 0x00000010", UInt64Rem(x, y), UInt64Create(0, 0));
+
+    x = UInt64Create(0x00000000, 0x000000F0);
+    y = UInt64Create(0x00000000, 0x00000010);
+    AssertEquals("0x00000000 0x000000F0 mod 0x00000010", UInt64Rem(x, y), UInt64Create(0, 0));
+
+	return 0;
+}