summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--src/bit.h96
-rw-r--r--tests/bit.c36
2 files changed, 63 insertions, 69 deletions
diff --git a/src/bit.h b/src/bit.h
index 17cfbcf..880ccd6 100644
--- a/src/bit.h
+++ b/src/bit.h
@@ -173,11 +173,7 @@
# define ENDIAN_NATIVE 0
#endif
-#if __STDC_VERSION__ >= C23
-# define bswap_u16 stdc_memreverse8u16
-# define bswap_u32 stdc_memreverse8u32
-# define bswap_u64 stdc_memreverse8u64
-#elif __GNUC__
+#if __GNUC__
# define bswap_u16 __builtin_bswap16
# define bswap_u32 __builtin_bswap32
# define bswap_u64 __builtin_bswap64
@@ -222,16 +218,10 @@ static inline uint8_t bswap_u8(uint8_t n) {
// Select an overload based on an unsigned integer type
#define UINT_SELECT(n, name) \
_Generic((n), \
- char: name##_uc, \
- signed char: name##_uc, \
unsigned char: name##_uc, \
- signed short: name##_us, \
unsigned short: name##_us, \
- signed int: name##_ui, \
unsigned int: name##_ui, \
- signed long: name##_ul, \
unsigned long: name##_ul, \
- signed long long: name##_ull, \
unsigned long long: name##_ull)
// C23 polyfill: bit utilities
@@ -239,8 +229,6 @@ static inline uint8_t bswap_u8(uint8_t n) {
#if __STDC_VERSION__ >= C23
# define count_ones stdc_count_ones
# define count_zeros stdc_count_zeros
-# define rotate_left stdc_rotate_left
-# define rotate_right stdc_rotate_right
# define leading_zeros stdc_leading_zeros
# define leading_ones stdc_leading_ones
# define trailing_zeros stdc_trailing_zeros
@@ -273,31 +261,31 @@ static inline uint8_t bswap_u8(uint8_t n) {
#define BUILTIN_WIDTH(suffix) BUILTIN_WIDTH##suffix
#define COUNT_ONES(type, suffix, width) \
- static inline int count_ones##suffix(type n) { \
+ static inline unsigned int count_ones##suffix(type n) { \
return UINT_BUILTIN(popcount, suffix)(n); \
}
#define LEADING_ZEROS(type, suffix, width) \
- static inline int leading_zeros##suffix(type n) { \
+ static inline unsigned int leading_zeros##suffix(type n) { \
return n \
? UINT_BUILTIN(clz, suffix)(n) - (BUILTIN_WIDTH(suffix) - width) \
: width; \
}
#define TRAILING_ZEROS(type, suffix, width) \
- static inline int trailing_zeros##suffix(type n) { \
+ static inline unsigned int trailing_zeros##suffix(type n) { \
return n ? UINT_BUILTIN(ctz, suffix)(n) : (int)width; \
}
#define FIRST_TRAILING_ONE(type, suffix, width) \
- static inline int first_trailing_one##suffix(type n) { \
+ static inline unsigned int first_trailing_one##suffix(type n) { \
return UINT_BUILTIN(ffs, suffix)(n); \
}
#else // !__GNUC__
#define COUNT_ONES(type, suffix, width) \
- static inline int count_ones##suffix(type n) { \
+ static inline unsigned int count_ones##suffix(type n) { \
int ret; \
for (ret = 0; n; ++ret) { \
n &= n - 1; \
@@ -306,7 +294,7 @@ static inline uint8_t bswap_u8(uint8_t n) {
}
#define LEADING_ZEROS(type, suffix, width) \
- static inline int leading_zeros##suffix(type n) { \
+ static inline unsigned int leading_zeros##suffix(type n) { \
type bit = (type)1 << (width - 1); \
int ret; \
for (ret = 0; bit && !(n & bit); ++ret, bit >>= 1); \
@@ -314,7 +302,7 @@ static inline uint8_t bswap_u8(uint8_t n) {
}
#define TRAILING_ZEROS(type, suffix, width) \
- static inline int trailing_zeros##suffix(type n) { \
+ static inline unsigned int trailing_zeros##suffix(type n) { \
type bit = 1; \
int ret; \
for (ret = 0; bit && !(n & bit); ++ret, bit <<= 1); \
@@ -322,7 +310,7 @@ static inline uint8_t bswap_u8(uint8_t n) {
}
#define FIRST_TRAILING_ONE(type, suffix, width) \
- static inline int first_trailing_one##suffix(type n) { \
+ static inline unsigned int first_trailing_one##suffix(type n) { \
return n ? trailing_zeros##suffix(n) + 1 : 0; \
}
@@ -333,19 +321,9 @@ UINT_OVERLOADS(LEADING_ZEROS)
UINT_OVERLOADS(TRAILING_ZEROS)
UINT_OVERLOADS(FIRST_TRAILING_ONE)
-#define ROTATE_LEFT(type, suffix, width) \
- static inline type rotate_left##suffix(type n, int c) { \
- return (n << c) | (n >> ((width - c) % width)); \
- }
-
-#define ROTATE_RIGHT(type, suffix, width) \
- static inline type rotate_right##suffix(type n, int c) { \
- return (n >> c) | (n << ((width - c) % width)); \
- }
-
#define FIRST_LEADING_ONE(type, suffix, width) \
- static inline int first_leading_one##suffix(type n) { \
- return width - leading_zeros##suffix(n); \
+ static inline unsigned int first_leading_one##suffix(type n) { \
+ return n ? leading_zeros##suffix(n) + 1 : 0; \
}
#define HAS_SINGLE_BIT(type, suffix, width) \
@@ -354,17 +332,30 @@ UINT_OVERLOADS(FIRST_TRAILING_ONE)
return n - 1 < (n ^ (n - 1)); \
}
-UINT_OVERLOADS(ROTATE_LEFT)
-UINT_OVERLOADS(ROTATE_RIGHT)
+#define BIT_WIDTH(type, suffix, width) \
+ static inline unsigned int bit_width##suffix(type n) { \
+ return width - leading_zeros##suffix(n); \
+ }
+
+#define BIT_FLOOR(type, suffix, width) \
+ static inline type bit_floor##suffix(type n) { \
+ return n ? (type)1 << (bit_width##suffix(n) - 1) : 0; \
+ }
+
+#define BIT_CEIL(type, suffix, width) \
+ static inline type bit_ceil##suffix(type n) { \
+ return (type)1 << bit_width##suffix(n - !!n); \
+ }
+
UINT_OVERLOADS(FIRST_LEADING_ONE)
UINT_OVERLOADS(HAS_SINGLE_BIT)
+UINT_OVERLOADS(BIT_WIDTH)
+UINT_OVERLOADS(BIT_FLOOR)
+UINT_OVERLOADS(BIT_CEIL)
#define count_ones(n) UINT_SELECT(n, count_ones)(n)
#define count_zeros(n) UINT_SELECT(n, count_ones)(~(n))
-#define rotate_left(n, c) UINT_SELECT(n, rotate_left)(n, c)
-#define rotate_right(n, c) UINT_SELECT(n, rotate_right)(n, c)
-
#define leading_zeros(n) UINT_SELECT(n, leading_zeros)(n)
#define leading_ones(n) UINT_SELECT(n, leading_zeros)(~(n))
@@ -379,23 +370,26 @@ UINT_OVERLOADS(HAS_SINGLE_BIT)
#define has_single_bit(n) UINT_SELECT(n, has_single_bit)(n)
-#define BIT_FLOOR(type, suffix, width) \
- static inline type bit_floor##suffix(type n) { \
- return n ? (type)1 << (first_leading_one##suffix(n) - 1) : 0; \
- }
+#define bit_width(n) UINT_SELECT(n, bit_width)(n)
+#define bit_floor(n) UINT_SELECT(n, bit_floor)(n)
+#define bit_ceil(n) UINT_SELECT(n, bit_ceil)(n)
-#define BIT_CEIL(type, suffix, width) \
- static inline type bit_ceil##suffix(type n) { \
- return (type)1 << first_leading_one##suffix(n - !!n); \
+#endif // __STDC_VERSION__ < C23
+
+#define ROTATE_LEFT(type, suffix, width) \
+ static inline type rotate_left##suffix(type n, int c) { \
+ return (n << c) | (n >> ((width - c) % width)); \
}
-UINT_OVERLOADS(BIT_FLOOR)
-UINT_OVERLOADS(BIT_CEIL)
+#define ROTATE_RIGHT(type, suffix, width) \
+ static inline type rotate_right##suffix(type n, int c) { \
+ return (n >> c) | (n << ((width - c) % width)); \
+ }
-#define bit_width(n) first_leading_one(n)
-#define bit_floor(n) UINT_SELECT(n, bit_floor)(n)
-#define bit_ceil(n) UINT_SELECT(n, bit_ceil)(n)
+UINT_OVERLOADS(ROTATE_LEFT)
+UINT_OVERLOADS(ROTATE_RIGHT)
-#endif // __STDC_VERSION__ < C23
+#define rotate_left(n, c) UINT_SELECT(n, rotate_left)(n, c)
+#define rotate_right(n, c) UINT_SELECT(n, rotate_right)(n, c)
#endif // BFS_BIT_H
diff --git a/tests/bit.c b/tests/bit.c
index 674d1b2..49e167d 100644
--- a/tests/bit.c
+++ b/tests/bit.c
@@ -76,15 +76,15 @@ bool check_bit(void) {
ret &= check_eq(bswap((uint32_t)0x12345678), 0x78563412);
ret &= check_eq(bswap((uint64_t)0x1234567812345678), 0x7856341278563412);
- ret &= check_eq(count_ones(0x0), 0);
- ret &= check_eq(count_ones(0x1), 1);
- ret &= check_eq(count_ones(0x2), 1);
- ret &= check_eq(count_ones(0x3), 2);
- ret &= check_eq(count_ones(0x137F), 10);
-
- ret &= check_eq(count_zeros(0), INT_WIDTH);
- ret &= check_eq(count_zeros(0L), LONG_WIDTH);
- ret &= check_eq(count_zeros(0LL), LLONG_WIDTH);
+ ret &= check_eq(count_ones(0x0U), 0);
+ ret &= check_eq(count_ones(0x1U), 1);
+ ret &= check_eq(count_ones(0x2U), 1);
+ ret &= check_eq(count_ones(0x3U), 2);
+ ret &= check_eq(count_ones(0x137FU), 10);
+
+ ret &= check_eq(count_zeros(0U), UINT_WIDTH);
+ ret &= check_eq(count_zeros(0UL), ULONG_WIDTH);
+ ret &= check_eq(count_zeros(0ULL), ULLONG_WIDTH);
ret &= check_eq(count_zeros((uint8_t)0), 8);
ret &= check_eq(count_zeros((uint16_t)0), 16);
ret &= check_eq(count_zeros((uint32_t)0), 32);
@@ -100,16 +100,16 @@ bool check_bit(void) {
ret &= check_eq(rotate_right((uint32_t)0x12345678, 20), 0x45678123);
ret &= check_eq(rotate_right((uint32_t)0x12345678, 0), 0x12345678);
- for (int i = 0; i < 16; ++i) {
+ for (unsigned int i = 0; i < 16; ++i) {
uint16_t n = (uint16_t)1 << i;
- for (int j = i; j < 16; ++j) {
+ for (unsigned int j = i; j < 16; ++j) {
uint16_t m = (uint16_t)1 << j;
uint16_t nm = n | m;
ret &= check_eq(count_ones(nm), 1 + (n != m));
ret &= check_eq(count_zeros(nm), 15 - (n != m));
ret &= check_eq(leading_zeros(nm), 15 - j);
ret &= check_eq(trailing_zeros(nm), i);
- ret &= check_eq(first_leading_one(nm), j + 1);
+ ret &= check_eq(first_leading_one(nm), 16 - j);
ret &= check_eq(first_trailing_one(nm), i + 1);
ret &= check_eq(bit_width(nm), j + 1);
ret &= check_eq(bit_floor(nm), m);
@@ -127,13 +127,13 @@ bool check_bit(void) {
ret &= check_eq(leading_zeros((uint16_t)0), 16);
ret &= check_eq(trailing_zeros((uint16_t)0), 16);
- ret &= check_eq(first_leading_one(0), 0);
- ret &= check_eq(first_trailing_one(0), 0);
- ret &= check_eq(bit_width(0), 0);
- ret &= check_eq(bit_floor(0), 0);
- ret &= check_eq(bit_ceil(0), 1);
+ ret &= check_eq(first_leading_one(0U), 0);
+ ret &= check_eq(first_trailing_one(0U), 0);
+ ret &= check_eq(bit_width(0U), 0);
+ ret &= check_eq(bit_floor(0U), 0);
+ ret &= check_eq(bit_ceil(0U), 1);
- ret &= bfs_check(!has_single_bit(0));
+ ret &= bfs_check(!has_single_bit(0U));
ret &= bfs_check(!has_single_bit(UINT32_MAX));
ret &= bfs_check(has_single_bit((uint32_t)1 << (UINT_WIDTH - 1)));
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 17:42:39 +0000