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opt_int_div.h: make test precision limit optional

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パチュリー・ノーレッジ 2024-03-09 19:29:11 +03:00
parent 4839ab2330
commit 0957b5dc49
Signed by: 80486DX2-66
GPG Key ID: 83631EF27054609B
1 changed files with 14 additions and 8 deletions
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22
c-programming/math/opt_int_div.h
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@ -11,7 +11,8 @@
#include <stdint.h>
// parameters
#define OPT_INT_DIV_TEST_PRECISION 8
#define OPT_INT_DIV_IS_TEST_PRECISION_LIMITED 0 /* true (1) or false (0) */
#define OPT_INT_DIV_TEST_PRECISION 8 /* only if the above parameter is 1 */
// constants
#define OPT_INT_DIV_ROUNDING \
@ -24,6 +25,16 @@
/* the sign is negative only if one of the numbers is negative */ \
(((a) < 0) ^ ((b) < 0)) /* 1 if sign is negative else 0 */
#define INT_ABS(x) ((x) < 0 ? -(x) : (x))
#define LOG2_DEC_PORTION(b) fmodl(log2l(INT_ABS((b))), 1.l)
#define OPT_INT_DIV_TEST(b) \
/* check if b is a power of 2 */ \
/* */ \
/* formula: round(log_2(b) % 1, OPT_INT_DIV_TEST_PRECISION digits */ \
/* after point) == 0 */ \
OPT_INT_DIV_IS_TEST_PRECISION_LIMITED ? \
roundl(LOG2_DEC_PORTION((b)) * OPT_INT_DIV_ROUNDING) == 0.l \
: \
LOG2_DEC_PORTION((b)) == 0.l
// the main macro
#define OPT_INT_DIV(a, b) \
@ -37,13 +48,8 @@
INT_ABS((a)) < INT_ABS((b)) ? \
0 : ( \
\
/* check if b is a power of 2 */ \
/* */ \
/* formula: round(log_2(b) % 1, OPT_INT_DIV_TEST_PRECISION digits */ \
/* after point) == 0 */ \
(roundl(fmodl(log2l(INT_ABS((b))), 1.l) * OPT_INT_DIV_ROUNDING) \
== 0.l) ? ( \
INT_DIV_NEG_RESULT_SIGN(a, b) ? \
OPT_INT_DIV_TEST((b)) ? \
(INT_DIV_NEG_RESULT_SIGN(a, b) ? \
-INT_BIN_DIV(INT_ABS((a)), INT_ABS((b))) \
: \
INT_BIN_DIV(INT_ABS((a)), INT_ABS((b)))) \