| /* intprops.h -- properties of integer types |
| |
| Copyright (C) 2001-2016 Free Software Foundation, Inc. |
| |
| This program is free software: you can redistribute it and/or modify it |
| under the terms of the GNU General Public License as published |
| by the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| |
| /* Written by Paul Eggert. */ |
| |
| #ifndef _GL_INTPROPS_H |
| #define _GL_INTPROPS_H |
| |
| #include <limits.h> |
| #include <verify.h> |
| |
| #ifndef __has_builtin |
| # define __has_builtin(x) 0 |
| #endif |
| |
| /* Return a value with the common real type of E and V and the value of V. */ |
| #define _GL_INT_CONVERT(e, v) (0 * (e) + (v)) |
| |
| /* Act like _GL_INT_CONVERT (E, -V) but work around a bug in IRIX 6.5 cc; see |
| <http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00406.html>. */ |
| #define _GL_INT_NEGATE_CONVERT(e, v) (0 * (e) - (v)) |
| |
| /* The extra casts in the following macros work around compiler bugs, |
| e.g., in Cray C 5.0.3.0. */ |
| |
| /* True if the arithmetic type T is an integer type. bool counts as |
| an integer. */ |
| #define TYPE_IS_INTEGER(t) ((t) 1.5 == 1) |
| |
| /* True if the real type T is signed. */ |
| #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) |
| |
| /* Return 1 if the real expression E, after promotion, has a |
| signed or floating type. */ |
| #define EXPR_SIGNED(e) (_GL_INT_NEGATE_CONVERT (e, 1) < 0) |
| |
| |
| /* Minimum and maximum values for integer types and expressions. */ |
| |
| /* The width in bits of the integer type or expression T. |
| Padding bits are not supported; this is checked at compile-time below. */ |
| #define TYPE_WIDTH(t) (sizeof (t) * CHAR_BIT) |
| |
| /* The maximum and minimum values for the integer type T. */ |
| #define TYPE_MINIMUM(t) ((t) ~ TYPE_MAXIMUM (t)) |
| #define TYPE_MAXIMUM(t) \ |
| ((t) (! TYPE_SIGNED (t) \ |
| ? (t) -1 \ |
| : ((((t) 1 << (TYPE_WIDTH (t) - 2)) - 1) * 2 + 1))) |
| |
| /* The maximum and minimum values for the type of the expression E, |
| after integer promotion. E should not have side effects. */ |
| #define _GL_INT_MINIMUM(e) \ |
| (EXPR_SIGNED (e) \ |
| ? ~ _GL_SIGNED_INT_MAXIMUM (e) \ |
| : _GL_INT_CONVERT (e, 0)) |
| #define _GL_INT_MAXIMUM(e) \ |
| (EXPR_SIGNED (e) \ |
| ? _GL_SIGNED_INT_MAXIMUM (e) \ |
| : _GL_INT_NEGATE_CONVERT (e, 1)) |
| #define _GL_SIGNED_INT_MAXIMUM(e) \ |
| (((_GL_INT_CONVERT (e, 1) << (TYPE_WIDTH ((e) + 0) - 2)) - 1) * 2 + 1) |
| |
| /* Work around OpenVMS incompatibility with C99. */ |
| #if !defined LLONG_MAX && defined __INT64_MAX |
| # define LLONG_MAX __INT64_MAX |
| # define LLONG_MIN __INT64_MIN |
| #endif |
| |
| /* This include file assumes that signed types are two's complement without |
| padding bits; the above macros have undefined behavior otherwise. |
| If this is a problem for you, please let us know how to fix it for your host. |
| As a sanity check, test the assumption for some signed types that |
| <limits.h> bounds. */ |
| verify (TYPE_MINIMUM (signed char) == SCHAR_MIN); |
| verify (TYPE_MAXIMUM (signed char) == SCHAR_MAX); |
| verify (TYPE_MINIMUM (short int) == SHRT_MIN); |
| verify (TYPE_MAXIMUM (short int) == SHRT_MAX); |
| verify (TYPE_MINIMUM (int) == INT_MIN); |
| verify (TYPE_MAXIMUM (int) == INT_MAX); |
| verify (TYPE_MINIMUM (long int) == LONG_MIN); |
| verify (TYPE_MAXIMUM (long int) == LONG_MAX); |
| #ifdef LLONG_MAX |
| verify (TYPE_MINIMUM (long long int) == LLONG_MIN); |
| verify (TYPE_MAXIMUM (long long int) == LLONG_MAX); |
| #endif |
| /* Similarly, sanity-check one ISO/IEC TS 18661-1:2014 macro if defined. */ |
| #ifdef UINT_WIDTH |
| verify (TYPE_WIDTH (unsigned int) == UINT_WIDTH); |
| #endif |
| |
| /* Does the __typeof__ keyword work? This could be done by |
| 'configure', but for now it's easier to do it by hand. */ |
| #if (2 <= __GNUC__ \ |
| || (1210 <= __IBMC__ && defined __IBM__TYPEOF__) \ |
| || (0x5110 <= __SUNPRO_C && !__STDC__)) |
| # define _GL_HAVE___TYPEOF__ 1 |
| #else |
| # define _GL_HAVE___TYPEOF__ 0 |
| #endif |
| |
| /* Return 1 if the integer type or expression T might be signed. Return 0 |
| if it is definitely unsigned. This macro does not evaluate its argument, |
| and expands to an integer constant expression. */ |
| #if _GL_HAVE___TYPEOF__ |
| # define _GL_SIGNED_TYPE_OR_EXPR(t) TYPE_SIGNED (__typeof__ (t)) |
| #else |
| # define _GL_SIGNED_TYPE_OR_EXPR(t) 1 |
| #endif |
| |
| /* Bound on length of the string representing an unsigned integer |
| value representable in B bits. log10 (2.0) < 146/485. The |
| smallest value of B where this bound is not tight is 2621. */ |
| #define INT_BITS_STRLEN_BOUND(b) (((b) * 146 + 484) / 485) |
| |
| /* Bound on length of the string representing an integer type or expression T. |
| Subtract 1 for the sign bit if T is signed, and then add 1 more for |
| a minus sign if needed. |
| |
| Because _GL_SIGNED_TYPE_OR_EXPR sometimes returns 0 when its argument is |
| signed, this macro may overestimate the true bound by one byte when |
| applied to unsigned types of size 2, 4, 16, ... bytes. */ |
| #define INT_STRLEN_BOUND(t) \ |
| (INT_BITS_STRLEN_BOUND (TYPE_WIDTH (t) - _GL_SIGNED_TYPE_OR_EXPR (t)) \ |
| + _GL_SIGNED_TYPE_OR_EXPR (t)) |
| |
| /* Bound on buffer size needed to represent an integer type or expression T, |
| including the terminating null. */ |
| #define INT_BUFSIZE_BOUND(t) (INT_STRLEN_BOUND (t) + 1) |
| |
| |
| /* Range overflow checks. |
| |
| The INT_<op>_RANGE_OVERFLOW macros return 1 if the corresponding C |
| operators might not yield numerically correct answers due to |
| arithmetic overflow. They do not rely on undefined or |
| implementation-defined behavior. Their implementations are simple |
| and straightforward, but they are a bit harder to use than the |
| INT_<op>_OVERFLOW macros described below. |
| |
| Example usage: |
| |
| long int i = ...; |
| long int j = ...; |
| if (INT_MULTIPLY_RANGE_OVERFLOW (i, j, LONG_MIN, LONG_MAX)) |
| printf ("multiply would overflow"); |
| else |
| printf ("product is %ld", i * j); |
| |
| Restrictions on *_RANGE_OVERFLOW macros: |
| |
| These macros do not check for all possible numerical problems or |
| undefined or unspecified behavior: they do not check for division |
| by zero, for bad shift counts, or for shifting negative numbers. |
| |
| These macros may evaluate their arguments zero or multiple times, |
| so the arguments should not have side effects. The arithmetic |
| arguments (including the MIN and MAX arguments) must be of the same |
| integer type after the usual arithmetic conversions, and the type |
| must have minimum value MIN and maximum MAX. Unsigned types should |
| use a zero MIN of the proper type. |
| |
| These macros are tuned for constant MIN and MAX. For commutative |
| operations such as A + B, they are also tuned for constant B. */ |
| |
| /* Return 1 if A + B would overflow in [MIN,MAX] arithmetic. |
| See above for restrictions. */ |
| #define INT_ADD_RANGE_OVERFLOW(a, b, min, max) \ |
| ((b) < 0 \ |
| ? (a) < (min) - (b) \ |
| : (max) - (b) < (a)) |
| |
| /* Return 1 if A - B would overflow in [MIN,MAX] arithmetic. |
| See above for restrictions. */ |
| #define INT_SUBTRACT_RANGE_OVERFLOW(a, b, min, max) \ |
| ((b) < 0 \ |
| ? (max) + (b) < (a) \ |
| : (a) < (min) + (b)) |
| |
| /* Return 1 if - A would overflow in [MIN,MAX] arithmetic. |
| See above for restrictions. */ |
| #define INT_NEGATE_RANGE_OVERFLOW(a, min, max) \ |
| ((min) < 0 \ |
| ? (a) < - (max) \ |
| : 0 < (a)) |
| |
| /* Return 1 if A * B would overflow in [MIN,MAX] arithmetic. |
| See above for restrictions. Avoid && and || as they tickle |
| bugs in Sun C 5.11 2010/08/13 and other compilers; see |
| <http://lists.gnu.org/archive/html/bug-gnulib/2011-05/msg00401.html>. */ |
| #define INT_MULTIPLY_RANGE_OVERFLOW(a, b, min, max) \ |
| ((b) < 0 \ |
| ? ((a) < 0 \ |
| ? (a) < (max) / (b) \ |
| : (b) == -1 \ |
| ? 0 \ |
| : (min) / (b) < (a)) \ |
| : (b) == 0 \ |
| ? 0 \ |
| : ((a) < 0 \ |
| ? (a) < (min) / (b) \ |
| : (max) / (b) < (a))) |
| |
| /* Return 1 if A / B would overflow in [MIN,MAX] arithmetic. |
| See above for restrictions. Do not check for division by zero. */ |
| #define INT_DIVIDE_RANGE_OVERFLOW(a, b, min, max) \ |
| ((min) < 0 && (b) == -1 && (a) < - (max)) |
| |
| /* Return 1 if A % B would overflow in [MIN,MAX] arithmetic. |
| See above for restrictions. Do not check for division by zero. |
| Mathematically, % should never overflow, but on x86-like hosts |
| INT_MIN % -1 traps, and the C standard permits this, so treat this |
| as an overflow too. */ |
| #define INT_REMAINDER_RANGE_OVERFLOW(a, b, min, max) \ |
| INT_DIVIDE_RANGE_OVERFLOW (a, b, min, max) |
| |
| /* Return 1 if A << B would overflow in [MIN,MAX] arithmetic. |
| See above for restrictions. Here, MIN and MAX are for A only, and B need |
| not be of the same type as the other arguments. The C standard says that |
| behavior is undefined for shifts unless 0 <= B < wordwidth, and that when |
| A is negative then A << B has undefined behavior and A >> B has |
| implementation-defined behavior, but do not check these other |
| restrictions. */ |
| #define INT_LEFT_SHIFT_RANGE_OVERFLOW(a, b, min, max) \ |
| ((a) < 0 \ |
| ? (a) < (min) >> (b) \ |
| : (max) >> (b) < (a)) |
| |
| /* True if __builtin_add_overflow (A, B, P) works when P is non-null. */ |
| #define _GL_HAS_BUILTIN_OVERFLOW \ |
| (5 <= __GNUC__ || __has_builtin (__builtin_add_overflow)) |
| |
| /* True if __builtin_add_overflow_p (A, B, C) works. */ |
| #define _GL_HAS_BUILTIN_OVERFLOW_P \ |
| (7 <= __GNUC__ || __has_builtin (__builtin_add_overflow_p)) |
| |
| /* The _GL*_OVERFLOW macros have the same restrictions as the |
| *_RANGE_OVERFLOW macros, except that they do not assume that operands |
| (e.g., A and B) have the same type as MIN and MAX. Instead, they assume |
| that the result (e.g., A + B) has that type. */ |
| #if _GL_HAS_BUILTIN_OVERFLOW_P |
| # define _GL_ADD_OVERFLOW(a, b, min, max) \ |
| __builtin_add_overflow_p (a, b, (__typeof__ ((a) + (b))) 0) |
| # define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \ |
| __builtin_sub_overflow_p (a, b, (__typeof__ ((a) - (b))) 0) |
| # define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \ |
| __builtin_mul_overflow_p (a, b, (__typeof__ ((a) * (b))) 0) |
| #else |
| # define _GL_ADD_OVERFLOW(a, b, min, max) \ |
| ((min) < 0 ? INT_ADD_RANGE_OVERFLOW (a, b, min, max) \ |
| : (a) < 0 ? (b) <= (a) + (b) \ |
| : (b) < 0 ? (a) <= (a) + (b) \ |
| : (a) + (b) < (b)) |
| # define _GL_SUBTRACT_OVERFLOW(a, b, min, max) \ |
| ((min) < 0 ? INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max) \ |
| : (a) < 0 ? 1 \ |
| : (b) < 0 ? (a) - (b) <= (a) \ |
| : (a) < (b)) |
| # define _GL_MULTIPLY_OVERFLOW(a, b, min, max) \ |
| (((min) == 0 && (((a) < 0 && 0 < (b)) || ((b) < 0 && 0 < (a)))) \ |
| || INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max)) |
| #endif |
| #define _GL_DIVIDE_OVERFLOW(a, b, min, max) \ |
| ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \ |
| : (a) < 0 ? (b) <= (a) + (b) - 1 \ |
| : (b) < 0 && (a) + (b) <= (a)) |
| #define _GL_REMAINDER_OVERFLOW(a, b, min, max) \ |
| ((min) < 0 ? (b) == _GL_INT_NEGATE_CONVERT (min, 1) && (a) < - (max) \ |
| : (a) < 0 ? (a) % (b) != ((max) - (b) + 1) % (b) \ |
| : (b) < 0 && ! _GL_UNSIGNED_NEG_MULTIPLE (a, b, max)) |
| |
| /* Return a nonzero value if A is a mathematical multiple of B, where |
| A is unsigned, B is negative, and MAX is the maximum value of A's |
| type. A's type must be the same as (A % B)'s type. Normally (A % |
| -B == 0) suffices, but things get tricky if -B would overflow. */ |
| #define _GL_UNSIGNED_NEG_MULTIPLE(a, b, max) \ |
| (((b) < -_GL_SIGNED_INT_MAXIMUM (b) \ |
| ? (_GL_SIGNED_INT_MAXIMUM (b) == (max) \ |
| ? (a) \ |
| : (a) % (_GL_INT_CONVERT (a, _GL_SIGNED_INT_MAXIMUM (b)) + 1)) \ |
| : (a) % - (b)) \ |
| == 0) |
| |
| /* Check for integer overflow, and report low order bits of answer. |
| |
| The INT_<op>_OVERFLOW macros return 1 if the corresponding C operators |
| might not yield numerically correct answers due to arithmetic overflow. |
| The INT_<op>_WRAPV macros also store the low-order bits of the answer. |
| These macros work correctly on all known practical hosts, and do not rely |
| on undefined behavior due to signed arithmetic overflow. |
| |
| Example usage, assuming A and B are long int: |
| |
| if (INT_MULTIPLY_OVERFLOW (a, b)) |
| printf ("result would overflow\n"); |
| else |
| printf ("result is %ld (no overflow)\n", a * b); |
| |
| Example usage with WRAPV flavor: |
| |
| long int result; |
| bool overflow = INT_MULTIPLY_WRAPV (a, b, &result); |
| printf ("result is %ld (%s)\n", result, |
| overflow ? "after overflow" : "no overflow"); |
| |
| Restrictions on these macros: |
| |
| These macros do not check for all possible numerical problems or |
| undefined or unspecified behavior: they do not check for division |
| by zero, for bad shift counts, or for shifting negative numbers. |
| |
| These macros may evaluate their arguments zero or multiple times, so the |
| arguments should not have side effects. |
| |
| The WRAPV macros are not constant expressions. They support only |
| +, binary -, and *. The result type must be signed. |
| |
| These macros are tuned for their last argument being a constant. |
| |
| Return 1 if the integer expressions A * B, A - B, -A, A * B, A / B, |
| A % B, and A << B would overflow, respectively. */ |
| |
| #define INT_ADD_OVERFLOW(a, b) \ |
| _GL_BINARY_OP_OVERFLOW (a, b, _GL_ADD_OVERFLOW) |
| #define INT_SUBTRACT_OVERFLOW(a, b) \ |
| _GL_BINARY_OP_OVERFLOW (a, b, _GL_SUBTRACT_OVERFLOW) |
| #if _GL_HAS_BUILTIN_OVERFLOW_P |
| # define INT_NEGATE_OVERFLOW(a) INT_SUBTRACT_OVERFLOW (0, a) |
| #else |
| # define INT_NEGATE_OVERFLOW(a) \ |
| INT_NEGATE_RANGE_OVERFLOW (a, _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a)) |
| #endif |
| #define INT_MULTIPLY_OVERFLOW(a, b) \ |
| _GL_BINARY_OP_OVERFLOW (a, b, _GL_MULTIPLY_OVERFLOW) |
| #define INT_DIVIDE_OVERFLOW(a, b) \ |
| _GL_BINARY_OP_OVERFLOW (a, b, _GL_DIVIDE_OVERFLOW) |
| #define INT_REMAINDER_OVERFLOW(a, b) \ |
| _GL_BINARY_OP_OVERFLOW (a, b, _GL_REMAINDER_OVERFLOW) |
| #define INT_LEFT_SHIFT_OVERFLOW(a, b) \ |
| INT_LEFT_SHIFT_RANGE_OVERFLOW (a, b, \ |
| _GL_INT_MINIMUM (a), _GL_INT_MAXIMUM (a)) |
| |
| /* Return 1 if the expression A <op> B would overflow, |
| where OP_RESULT_OVERFLOW (A, B, MIN, MAX) does the actual test, |
| assuming MIN and MAX are the minimum and maximum for the result type. |
| Arguments should be free of side effects. */ |
| #define _GL_BINARY_OP_OVERFLOW(a, b, op_result_overflow) \ |
| op_result_overflow (a, b, \ |
| _GL_INT_MINIMUM (0 * (b) + (a)), \ |
| _GL_INT_MAXIMUM (0 * (b) + (a))) |
| |
| /* Store the low-order bits of A + B, A - B, A * B, respectively, into *R. |
| Return 1 if the result overflows. See above for restrictions. */ |
| #define INT_ADD_WRAPV(a, b, r) \ |
| _GL_INT_OP_WRAPV (a, b, r, +, __builtin_add_overflow, INT_ADD_OVERFLOW) |
| #define INT_SUBTRACT_WRAPV(a, b, r) \ |
| _GL_INT_OP_WRAPV (a, b, r, -, __builtin_sub_overflow, INT_SUBTRACT_OVERFLOW) |
| #define INT_MULTIPLY_WRAPV(a, b, r) \ |
| _GL_INT_OP_WRAPV (a, b, r, *, __builtin_mul_overflow, INT_MULTIPLY_OVERFLOW) |
| |
| /* Nonzero if this compiler has GCC bug 68193 or Clang bug 25390. See: |
| https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68193 |
| https://llvm.org/bugs/show_bug.cgi?id=25390 |
| For now, assume all versions of GCC-like compilers generate bogus |
| warnings for _Generic. This matters only for older compilers that |
| lack __builtin_add_overflow. */ |
| #if __GNUC__ |
| # define _GL__GENERIC_BOGUS 1 |
| #else |
| # define _GL__GENERIC_BOGUS 0 |
| #endif |
| |
| /* Store the low-order bits of A <op> B into *R, where OP specifies |
| the operation. BUILTIN is the builtin operation, and OVERFLOW the |
| overflow predicate. Return 1 if the result overflows. See above |
| for restrictions. */ |
| #if _GL_HAS_BUILTIN_OVERFLOW |
| # define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) builtin (a, b, r) |
| #elif 201112 <= __STDC_VERSION__ && !_GL__GENERIC_BOGUS |
| # define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \ |
| (_Generic \ |
| (*(r), \ |
| signed char: \ |
| _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \ |
| signed char, SCHAR_MIN, SCHAR_MAX), \ |
| short int: \ |
| _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \ |
| short int, SHRT_MIN, SHRT_MAX), \ |
| int: \ |
| _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ |
| int, INT_MIN, INT_MAX), \ |
| long int: \ |
| _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \ |
| long int, LONG_MIN, LONG_MAX), \ |
| long long int: \ |
| _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \ |
| long long int, LLONG_MIN, LLONG_MAX))) |
| #else |
| # define _GL_INT_OP_WRAPV(a, b, r, op, builtin, overflow) \ |
| (sizeof *(r) == sizeof (signed char) \ |
| ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned char, \ |
| signed char, SCHAR_MIN, SCHAR_MAX) \ |
| : sizeof *(r) == sizeof (short int) \ |
| ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned short int, \ |
| short int, SHRT_MIN, SHRT_MAX) \ |
| : sizeof *(r) == sizeof (int) \ |
| ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned int, \ |
| int, INT_MIN, INT_MAX) \ |
| : _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow)) |
| # ifdef LLONG_MAX |
| # define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \ |
| (sizeof *(r) == sizeof (long int) \ |
| ? _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \ |
| long int, LONG_MIN, LONG_MAX) \ |
| : _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long long int, \ |
| long long int, LLONG_MIN, LLONG_MAX)) |
| # else |
| # define _GL_INT_OP_WRAPV_LONGISH(a, b, r, op, overflow) \ |
| _GL_INT_OP_CALC (a, b, r, op, overflow, unsigned long int, \ |
| long int, LONG_MIN, LONG_MAX) |
| # endif |
| #endif |
| |
| /* Store the low-order bits of A <op> B into *R, where the operation |
| is given by OP. Use the unsigned type UT for calculation to avoid |
| overflow problems. *R's type is T, with extremal values TMIN and |
| TMAX. T must be a signed integer type. Return 1 if the result |
| overflows. */ |
| #define _GL_INT_OP_CALC(a, b, r, op, overflow, ut, t, tmin, tmax) \ |
| (sizeof ((a) op (b)) < sizeof (t) \ |
| ? _GL_INT_OP_CALC1 ((t) (a), (t) (b), r, op, overflow, ut, t, tmin, tmax) \ |
| : _GL_INT_OP_CALC1 (a, b, r, op, overflow, ut, t, tmin, tmax)) |
| #define _GL_INT_OP_CALC1(a, b, r, op, overflow, ut, t, tmin, tmax) \ |
| ((overflow (a, b) \ |
| || (EXPR_SIGNED ((a) op (b)) && ((a) op (b)) < (tmin)) \ |
| || (tmax) < ((a) op (b))) \ |
| ? (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 1) \ |
| : (*(r) = _GL_INT_OP_WRAPV_VIA_UNSIGNED (a, b, op, ut, t, tmin, tmax), 0)) |
| |
| /* Return A <op> B, where the operation is given by OP. Use the |
| unsigned type UT for calculation to avoid overflow problems. |
| Convert the result to type T without overflow by subtracting TMIN |
| from large values before converting, and adding it afterwards. |
| Compilers can optimize all the operations except OP. */ |
| #define _GL_INT_OP_WRAPV_VIA_UNSIGNED(a, b, op, ut, t, tmin, tmax) \ |
| (((ut) (a) op (ut) (b)) <= (tmax) \ |
| ? (t) ((ut) (a) op (ut) (b)) \ |
| : ((t) (((ut) (a) op (ut) (b)) - (tmin)) + (tmin))) |
| |
| #endif /* _GL_INTPROPS_H */ |
