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Improve new C23 checked arithmetic feature

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Justine Tunney 2023-06-16 15:32:18 -07:00
parent 2a1c588826
commit 4eebd6b9dc
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10 changed files with 341 additions and 15 deletions
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91
libc/stdckdint.h
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@ -1,8 +1,93 @@
#ifndef COSMOPOLITAN_LIBC_STDCKDINT_H_
#define COSMOPOLITAN_LIBC_STDCKDINT_H_
#if !defined(MODE_DBG) && \
((defined(__GNUC__) && __GNUC__ >= 5 && !defined(__ICC)) || \
(defined(__has_builtin) && (__has_builtin(__builtin_add_overflow) && \
__has_builtin(__builtin_sub_overflow) && \
__has_builtin(__builtin_mul_overflow))))
#define ckd_add(R, A, B) __builtin_add_overflow((A), (B), (R))
#define ckd_sub(R, A, B) __builtin_sub_overflow((A), (B), (R))
#define ckd_mul(R, A, B) __builtin_mul_overflow((A), (B), (R))
#define ckd_add(res, x, y) __builtin_add_overflow((x), (y), (res))
#define ckd_sub(res, x, y) __builtin_sub_overflow((x), (y), (res))
#define ckd_mul(res, x, y) __builtin_mul_overflow((x), (y), (res))
#else
#define ckd_add(res, x, y) __ckd_arithmetic(add, res, x, y)
#define ckd_sub(res, x, y) __ckd_arithmetic(sub, res, x, y)
#define ckd_mul(res, x, y) __ckd_arithmetic(mul, res, x, y)
#if defined(__SIZEOF_LONG__) && __SIZEOF_LONG__ == 8 && \
((defined(__GNUC__) && __GNUC__ * 100 + __GNUC_MINOR__ >= 406) || \
defined(__llvm__)) && \
!defined(__STRICT_ANSI__)
#define __ckd_dword __int128
#else
#define __ckd_dword long long
#endif
#define __ckd_arithmetic(op, res, x, y) \
(sizeof(*(res)) == sizeof(int) ? __ckd_##op((int *)(res), (x), (y)) \
: sizeof(*(res)) == sizeof(long) ? __ckd_##op##l((long *)(res), (x), (y)) \
: sizeof(*(res)) == sizeof(__ckd_dword) \
? __ckd_##op##ll((__ckd_dword *)(res), (x), (y)) \
: __ckd_trap())
__funline int __ckd_trap(void) {
volatile int __x = 0;
return 1 / __x;
}
__funline int __ckd_add(int *__z, int __x, int __y) {
unsigned int __a, __b, __c;
*__z = __c = (__a = __x) + (__b = __y);
return ((__c ^ __a) & (__c ^ __b)) >> (sizeof(int) * CHAR_BIT - 1);
}
__funline int __ckd_addl(long *__z, long __x, long __y) {
unsigned long __a, __b, __c;
*__z = __c = (__a = __x) + (__b = __y);
return ((__c ^ __a) & (__c ^ __b)) >> (sizeof(long) * CHAR_BIT - 1);
}
__funline int __ckd_addll(__ckd_dword *__z, __ckd_dword __x, __ckd_dword __y) {
unsigned __ckd_dword __a, __b, __c;
*__z = __c = (__a = __x) + (__b = __y);
return ((__c ^ __a) & (__c ^ __b)) >> (sizeof(__ckd_dword) * CHAR_BIT - 1);
}
__funline int __ckd_sub(int *__z, int __x, int __y) {
unsigned int __a, __b, __c;
*__z = __c = (__a = __x) - (__b = __y);
return ((__a ^ __b) & (__c ^ __a)) >> (sizeof(int) * CHAR_BIT - 1);
}
__funline int __ckd_subl(long *__z, long __x, long __y) {
unsigned long __a, __b, __c;
*__z = __c = (__a = __x) - (__b = __y);
return ((__a ^ __b) & (__c ^ __a)) >> (sizeof(long) * CHAR_BIT - 1);
}
__funline int __ckd_subll(__ckd_dword *__z, __ckd_dword __x, __ckd_dword __y) {
unsigned __ckd_dword __a, __b, __c;
*__z = __c = (__a = __x) - (__b = __y);
return ((__a ^ __b) & (__c ^ __a)) >> (sizeof(__ckd_dword) * CHAR_BIT - 1);
}
int __mulosi4(int, int, int *);
long __mulodi4(long, long, int *);
__ckd_dword __muloti4(__ckd_dword, __ckd_dword, int *);
__funline int __ckd_mul(int *__z, int __x, int __y) {
int __o;
*__z = __mulosi4(__x, __y, &__o);
return __o;
}
__funline int __ckd_mull(long *__z, long __x, long __y) {
int __o;
*__z = __mulodi4(__x, __y, &__o);
return __o;
}
__funline int __ckd_mulll(__ckd_dword *__z, __ckd_dword __x, __ckd_dword __y) {
int __o;
*__z = __muloti4(__x, __y, &__o);
return __o;
}
#endif
#endif /* COSMOPOLITAN_LIBC_STDCKDINT_H_ */