%% options copyright owner = Dirk Krause copyright year = 2015-xxxx license = bsd %% header /** @file Arithmetic operations on signed char. CRT on Windows: Optional. */ #ifndef DK4CONF_H_INCLUDED #include "dk4conf.h" #endif #ifndef DK4TYPES_H_INCLUDED #include "dk4types.h" #endif #ifndef DK4ERROR_H_INCLUDED #include "dk4error.h" #endif #ifdef __cplusplus extern "C" { #endif /** Absolute value. @param a Operand. @param erp Error report, may be NULL. @return Result on success, SCHAR_MAX if a is SCHAR_MIN (overflow is reported in erp). Error codes: DK4_E_OVERFLOW. */ signed char dk4ma_char_abs(signed char a, dk4_er_t *erp); /** Addition. @param a Left operand. @param b Right operand. @param erp Error report, may be NULL. @return Result on success, least significant result bits on overflow (see ec component of erp). Error codes: DK4_E_OVERFLOW. */ signed char dk4ma_char_add(signed char a, signed char b, dk4_er_t *erp); /** Subtraction. @param a Left operand. @param b Right operand. @param erp Error report, may be NULL. @return Result on success, least significant result bits on overflow (see ec component of erp). Error codes: DK4_E_OVERFLOW. */ signed char dk4ma_char_sub(signed char a, signed char b, dk4_er_t *erp); /** Multiplication. @param a Left factor. @param b right factor. @param erp Error report, may be NULL. @return Result on success, least significant bits on overflow (see ec component of erp). Error codes: DK4_E_OVERFLOW. */ signed char dk4ma_char_mul(signed char a, signed char b, dk4_er_t *erp); /** Division. @param a Counter (left operand). @param b Denominator (right operand). @param erp Error report, may be NULL. @return Division result on success, SCHAR_MIN, SCHAR_MAX, or 0 on division by zero or overflow (see the ec component of erp). Error codes: DK4_E_OVERFLOW, DK4_E_DIVZERO. */ signed char dk4ma_char_div(signed char a, signed char b, dk4_er_t *erp); #ifdef __cplusplus } #endif %% module #include "dk4conf.h" #include "dk4types.h" #include "dk4error.h" #include "dk4numco.h" #include "dk4maac.h" $!trace-include signed char dk4ma_char_abs(signed char a, dk4_er_t *erp) { if (SCHAR_MIN == a) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } return (signed char)((0 <= a) ? a : ((SCHAR_MIN == a) ? SCHAR_MAX : (0 - a))); } signed char dk4ma_char_add(signed char a, signed char b, dk4_er_t *erp) { if ((0 < a) && (0 < b)) { if ((SCHAR_MAX - a) < b) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } else { if ((0 > a) && (0 > b)) { if (SCHAR_MIN == a) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } else { if ((SCHAR_MIN - a) > b) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } } } return (signed char)(a + b); } signed char dk4ma_char_sub(signed char a, signed char b, dk4_er_t *erp) { if ((0 < a) && (0 > b)) { if ((SCHAR_MAX + b) < a) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } else { if ((0 > a) && (0 < b)) { if ((SCHAR_MIN + b) > a) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } } return (signed char)(a - b); } signed char dk4ma_char_mul(signed char a, signed char b, dk4_er_t *erp) { $? "+ dk4ma_char_mul %d %d", (int)a, (int)b if ((0 != a) && (0 != b)) { if (SCHAR_MIN == a) { if ((signed char)1 != b) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } else { if (SCHAR_MIN == b) { if ((signed char)1 != a) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } else { if (0 < a) { if (0 < b) { if ((SCHAR_MAX / a) < b) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } else { if ((SCHAR_MIN / a) > b) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } } else { if (0 < b) { if ((SCHAR_MIN / b) > a) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } else { if ((SCHAR_MAX / (0 - a)) < (0 - b)) { dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } } } } } } $? "- dk4ma_char_mul %d", (int)((signed char)(a * b)) return (signed char)(a * b); } signed char dk4ma_char_div(signed char a, signed char b, dk4_er_t *erp) { signed char back = 0; if (0 != b) { if ((SCHAR_MIN == a) && (-1 == b)) { back = SCHAR_MAX; dk4error_set_simple_error_code(erp, DK4_E_MATH_OVERFLOW); } else { back = a / b; } } else { if (0 < a) back = SCHAR_MAX; if (0 > b) back = SCHAR_MIN; dk4error_set_simple_error_code(erp, DK4_E_MATH_DIVZERO); } return back; }