tests/bit.c

   1 // Copyright © Tavian Barnes <tavianator@tavianator.com>
   2 // SPDX-License-Identifier: 0BSD
   3
   4 #include "../src/bit.h"
   5 #include "../src/diag.h"
   6 #include <limits.h>
   7 #include <stdint.h>
   8 #include <stdlib.h>
   9
  10 bfs_static_assert(UMAX_WIDTH(0x1) == 1);
  11 bfs_static_assert(UMAX_WIDTH(0x3) == 2);
  12 bfs_static_assert(UMAX_WIDTH(0x7) == 3);
  13 bfs_static_assert(UMAX_WIDTH(0xF) == 4);
  14 bfs_static_assert(UMAX_WIDTH(0xFF) == 8);
  15 bfs_static_assert(UMAX_WIDTH(0xFFF) == 12);
  16 bfs_static_assert(UMAX_WIDTH(0xFFFF) == 16);
  17
  18 #define UWIDTH_MAX(n) (2 * ((UINTMAX_C(1) << ((n) - 1)) - 1) + 1)
  19 #define IWIDTH_MAX(n) UWIDTH_MAX((n) - 1)
  20 #define IWIDTH_MIN(n) (-(intmax_t)IWIDTH_MAX(n) - 1)
  21
  22 bfs_static_assert(UCHAR_MAX == UWIDTH_MAX(UCHAR_WIDTH));
  23 bfs_static_assert(SCHAR_MIN == IWIDTH_MIN(SCHAR_WIDTH));
  24 bfs_static_assert(SCHAR_MAX == IWIDTH_MAX(SCHAR_WIDTH));
  25
  26 bfs_static_assert(USHRT_MAX == UWIDTH_MAX(USHRT_WIDTH));
  27 bfs_static_assert(SHRT_MIN == IWIDTH_MIN(SHRT_WIDTH));
  28 bfs_static_assert(SHRT_MAX == IWIDTH_MAX(SHRT_WIDTH));
  29
  30 bfs_static_assert(UINT_MAX == UWIDTH_MAX(UINT_WIDTH));
  31 bfs_static_assert(INT_MIN == IWIDTH_MIN(INT_WIDTH));
  32 bfs_static_assert(INT_MAX == IWIDTH_MAX(INT_WIDTH));
  33
  34 bfs_static_assert(ULONG_MAX == UWIDTH_MAX(ULONG_WIDTH));
  35 bfs_static_assert(LONG_MIN == IWIDTH_MIN(LONG_WIDTH));
  36 bfs_static_assert(LONG_MAX == IWIDTH_MAX(LONG_WIDTH));
  37
  38 bfs_static_assert(ULLONG_MAX == UWIDTH_MAX(ULLONG_WIDTH));
  39 bfs_static_assert(LLONG_MIN == IWIDTH_MIN(LLONG_WIDTH));
  40 bfs_static_assert(LLONG_MAX == IWIDTH_MAX(LLONG_WIDTH));
  41
  42 bfs_static_assert(SIZE_MAX == UWIDTH_MAX(SIZE_WIDTH));
  43 bfs_static_assert(PTRDIFF_MIN == IWIDTH_MIN(PTRDIFF_WIDTH));
  44 bfs_static_assert(PTRDIFF_MAX == IWIDTH_MAX(PTRDIFF_WIDTH));
  45
  46 bfs_static_assert(UINTPTR_MAX == UWIDTH_MAX(UINTPTR_WIDTH));
  47 bfs_static_assert(INTPTR_MIN == IWIDTH_MIN(INTPTR_WIDTH));
  48 bfs_static_assert(INTPTR_MAX == IWIDTH_MAX(INTPTR_WIDTH));
  49
  50 bfs_static_assert(UINTMAX_MAX == UWIDTH_MAX(UINTMAX_WIDTH));
  51 bfs_static_assert(INTMAX_MIN == IWIDTH_MIN(INTMAX_WIDTH));
  52 bfs_static_assert(INTMAX_MAX == IWIDTH_MAX(INTMAX_WIDTH));
  53
  54 #define verify_eq(a, b) \
  55         bfs_verify((a) == (b), "(0x%jX) %s != %s (0x%jX)", (uintmax_t)(a), #a, #b, (uintmax_t)(b))
  56
  57 int main(void) {
  58         verify_eq(bswap((uint8_t)0x12), 0x12);
  59         verify_eq(bswap((uint16_t)0x1234), 0x3412);
  60         verify_eq(bswap((uint32_t)0x12345678), 0x78563412);
  61         verify_eq(bswap((uint64_t)0x1234567812345678), 0x7856341278563412);
  62
  63         verify_eq(count_ones(0x0), 0);
  64         verify_eq(count_ones(0x1), 1);
  65         verify_eq(count_ones(0x2), 1);
  66         verify_eq(count_ones(0x3), 2);
  67         verify_eq(count_ones(0x137F), 10);
  68
  69         verify_eq(count_zeros(0), INT_WIDTH);
  70         verify_eq(count_zeros(0L), LONG_WIDTH);
  71         verify_eq(count_zeros(0LL), LLONG_WIDTH);
  72         verify_eq(count_zeros((uint8_t)0), 8);
  73         verify_eq(count_zeros((uint16_t)0), 16);
  74         verify_eq(count_zeros((uint32_t)0), 32);
  75         verify_eq(count_zeros((uint64_t)0), 64);
  76
  77         verify_eq(rotate_left((uint8_t)0xA1, 4), 0x1A);
  78         verify_eq(rotate_left((uint16_t)0x1234, 12), 0x4123);
  79         verify_eq(rotate_left((uint32_t)0x12345678, 20), 0x67812345);
  80         verify_eq(rotate_left((uint32_t)0x12345678, 0), 0x12345678);
  81
  82         verify_eq(rotate_right((uint8_t)0xA1, 4), 0x1A);
  83         verify_eq(rotate_right((uint16_t)0x1234, 12), 0x2341);
  84         verify_eq(rotate_right((uint32_t)0x12345678, 20), 0x45678123);
  85         verify_eq(rotate_right((uint32_t)0x12345678, 0), 0x12345678);
  86
  87         for (int i = 0; i < 16; ++i) {
  88                 uint16_t n = (uint16_t)1 << i;
  89                 for (int j = i; j < 16; ++j) {
  90                         uint16_t m = (uint16_t)1 << j;
  91                         uint16_t nm = n | m;
  92                         verify_eq(count_ones(nm), 1 + (n != m));
  93                         verify_eq(count_zeros(nm), 15 - (n != m));
  94                         verify_eq(leading_zeros(nm), 15 - j);
  95                         verify_eq(trailing_zeros(nm), i);
  96                         verify_eq(first_leading_one(nm), j + 1);
  97                         verify_eq(first_trailing_one(nm), i + 1);
  98                         verify_eq(bit_width(nm), j + 1);
  99                         verify_eq(bit_floor(nm), m);
 100                         if (n == m) {
 101                                 verify_eq(bit_ceil(nm), m);
 102                                 bfs_verify(has_single_bit(nm));
 103                         } else {
 104                                 if (j < 15) {
 105                                         verify_eq(bit_ceil(nm), (m << 1));
 106                                 }
 107                                 bfs_verify(!has_single_bit(nm));
 108                         }
 109                 }
 110         }
 111
 112         verify_eq(leading_zeros((uint16_t)0), 16);
 113         verify_eq(trailing_zeros((uint16_t)0), 16);
 114         verify_eq(first_leading_one(0), 0);
 115         verify_eq(first_trailing_one(0), 0);
 116         verify_eq(bit_width(0), 0);
 117         verify_eq(bit_floor(0), 0);
 118         verify_eq(bit_ceil(0), 1);
 119
 120         return EXIT_SUCCESS;
 121 }