bit: Rename int.h to bit.h

1 files changed, 121 insertions, 0 deletions

diff --git a/tests/bit.c b/tests/bit.c
new file mode 100644
index 0000000..7a7b0f3
--- /dev/null
+++ b/tests/bit.c
@@ -0,0 +1,121 @@
+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+#undef NDEBUG
+
+#include "../src/bit.h"
+#include "../src/diag.h"
+#include <assert.h>
+#include <limits.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+bfs_static_assert(UMAX_WIDTH(0x1) == 1);
+bfs_static_assert(UMAX_WIDTH(0x3) == 2);
+bfs_static_assert(UMAX_WIDTH(0x7) == 3);
+bfs_static_assert(UMAX_WIDTH(0xF) == 4);
+bfs_static_assert(UMAX_WIDTH(0xFF) == 8);
+bfs_static_assert(UMAX_WIDTH(0xFFF) == 12);
+bfs_static_assert(UMAX_WIDTH(0xFFFF) == 16);
+
+#define UWIDTH_MAX(n) (2 * ((UINTMAX_C(1) << ((n) - 1)) - 1) + 1)
+#define IWIDTH_MAX(n) UWIDTH_MAX((n) - 1)
+#define IWIDTH_MIN(n) (-(intmax_t)IWIDTH_MAX(n) - 1)
+
+bfs_static_assert(UCHAR_MAX == UWIDTH_MAX(UCHAR_WIDTH));
+bfs_static_assert(SCHAR_MIN == IWIDTH_MIN(SCHAR_WIDTH));
+bfs_static_assert(SCHAR_MAX == IWIDTH_MAX(SCHAR_WIDTH));
+
+bfs_static_assert(USHRT_MAX == UWIDTH_MAX(USHRT_WIDTH));
+bfs_static_assert(SHRT_MIN == IWIDTH_MIN(SHRT_WIDTH));
+bfs_static_assert(SHRT_MAX == IWIDTH_MAX(SHRT_WIDTH));
+
+bfs_static_assert(UINT_MAX == UWIDTH_MAX(UINT_WIDTH));
+bfs_static_assert(INT_MIN == IWIDTH_MIN(INT_WIDTH));
+bfs_static_assert(INT_MAX == IWIDTH_MAX(INT_WIDTH));
+
+bfs_static_assert(ULONG_MAX == UWIDTH_MAX(ULONG_WIDTH));
+bfs_static_assert(LONG_MIN == IWIDTH_MIN(LONG_WIDTH));
+bfs_static_assert(LONG_MAX == IWIDTH_MAX(LONG_WIDTH));
+
+bfs_static_assert(ULLONG_MAX == UWIDTH_MAX(ULLONG_WIDTH));
+bfs_static_assert(LLONG_MIN == IWIDTH_MIN(LLONG_WIDTH));
+bfs_static_assert(LLONG_MAX == IWIDTH_MAX(LLONG_WIDTH));
+
+bfs_static_assert(SIZE_MAX == UWIDTH_MAX(SIZE_WIDTH));
+bfs_static_assert(PTRDIFF_MIN == IWIDTH_MIN(PTRDIFF_WIDTH));
+bfs_static_assert(PTRDIFF_MAX == IWIDTH_MAX(PTRDIFF_WIDTH));
+
+bfs_static_assert(UINTPTR_MAX == UWIDTH_MAX(UINTPTR_WIDTH));
+bfs_static_assert(INTPTR_MIN == IWIDTH_MIN(INTPTR_WIDTH));
+bfs_static_assert(INTPTR_MAX == IWIDTH_MAX(INTPTR_WIDTH));
+
+bfs_static_assert(UINTMAX_MAX == UWIDTH_MAX(UINTMAX_WIDTH));
+bfs_static_assert(INTMAX_MIN == IWIDTH_MIN(INTMAX_WIDTH));
+bfs_static_assert(INTMAX_MAX == IWIDTH_MAX(INTMAX_WIDTH));
+
+int main(void) {
+	assert(bswap((uint8_t)0x12) == 0x12);
+	assert(bswap((uint16_t)0x1234) == 0x3412);
+	assert(bswap((uint32_t)0x12345678) == 0x78563412);
+	assert(bswap((uint64_t)0x1234567812345678) == 0x7856341278563412);
+
+	assert(count_ones(0x0) == 0);
+	assert(count_ones(0x1) == 1);
+	assert(count_ones(0x2) == 1);
+	assert(count_ones(0x3) == 2);
+	assert(count_ones(0x137F) == 10);
+
+	assert(count_zeros(0) == INT_WIDTH);
+	assert(count_zeros(0L) == LONG_WIDTH);
+	assert(count_zeros(0LL) == LLONG_WIDTH);
+	assert(count_zeros((uint8_t)0) == 8);
+	assert(count_zeros((uint16_t)0) == 16);
+	assert(count_zeros((uint32_t)0) == 32);
+	assert(count_zeros((uint64_t)0) == 64);
+
+	assert(rotate_left((uint8_t)0xA1, 4) == 0x1A);
+	assert(rotate_left((uint16_t)0x1234, 12) == 0x4123);
+	assert(rotate_left((uint32_t)0x12345678, 20) == 0x67812345);
+	assert(rotate_left((uint32_t)0x12345678, 0) == 0x12345678);
+
+	assert(rotate_right((uint8_t)0xA1, 4) == 0x1A);
+	assert(rotate_right((uint16_t)0x1234, 12) == 0x2341);
+	assert(rotate_right((uint32_t)0x12345678, 20) == 0x45678123);
+	assert(rotate_right((uint32_t)0x12345678, 0) == 0x12345678);
+
+	for (int i = 0; i < 16; ++i) {
+		uint16_t n = (uint16_t)1 << i;
+		for (int j = i; j < 16; ++j) {
+			uint16_t m = (uint16_t)1 << j;
+			uint16_t nm = n | m;
+			assert(count_ones(nm) == 1 + (n != m));
+			assert(count_zeros(nm) == 15 - (n != m));
+			assert(leading_zeros(nm) == 15 - j);
+			assert(trailing_zeros(nm) == i);
+			assert(first_leading_one(nm) == j + 1);
+			assert(first_trailing_one(nm) == i + 1);
+			assert(bit_width(nm) == j + 1);
+			assert(bit_floor(nm) == m);
+			if (n == m) {
+				assert(bit_ceil(nm) == m);
+				assert(has_single_bit(nm));
+			} else {
+				if (j < 15) {
+					assert(bit_ceil(nm) == (m << 1));
+				}
+				assert(!has_single_bit(nm));
+			}
+		}
+	}
+
+	assert(leading_zeros((uint16_t)0) == 16);
+	assert(trailing_zeros((uint16_t)0) == 16);
+	assert(first_leading_one(0) == 0);
+	assert(first_trailing_one(0) == 0);
+	assert(bit_width(0) == 0);
+	assert(bit_floor(0) == 0);
+	assert(bit_ceil(0) == 1);
+
+	return EXIT_SUCCESS;
+}