michaelh/zephyr
1
0
Fork 0
Code Releases Activity

math: extras: Add overflow functions to u16

Browse source 
Add functions to addition and multiplication for u16_t.

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
This commit is contained in:
Flavio Ceolin 2020-04-16 22:48:44 -07:00 • committed by Jukka Rissanen
commit 025dd14c25
2 changed files with 30 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

2
include/sys/math_extras.h
View file

@ -28,6 +28,7 @@
* true if the operation overflowed.
*/
/**@{*/
static bool u16_add_overflow(u16_t a, u16_t b, u16_t *result);
static bool u32_add_overflow(u32_t a, u32_t b, u32_t *result);
static bool u64_add_overflow(u64_t a, u64_t b, u64_t *result);
static bool size_add_overflow(size_t a, size_t b, size_t *result);
@ -40,6 +41,7 @@ static bool size_add_overflow(size_t a, size_t b, size_t *result);
* true if the operation overflowed.
*/
/**@{*/
static bool u16_mul_overflow(u16_t a, u16_t b, u16_t *result);
static bool u32_mul_overflow(u32_t a, u32_t b, u32_t *result);
static bool u64_mul_overflow(u64_t a, u64_t b, u64_t *result);
static bool size_mul_overflow(size_t a, size_t b, size_t *result);

28
include/sys/math_extras_impl.h
View file

@ -29,6 +29,11 @@
#endif
#if use_builtin(__builtin_add_overflow)
static inline bool u16_add_overflow(u16_t a, u16_t b, u16_t *result)
{
return __builtin_add_overflow(a, b, result);
}
static inline bool u32_add_overflow(u32_t a, u32_t b, u32_t *result)
{
return __builtin_add_overflow(a, b, result);
@ -44,6 +49,15 @@ static inline bool size_add_overflow(size_t a, size_t b, size_t *result)
return __builtin_add_overflow(a, b, result);
}
#else /* !use_builtin(__builtin_add_overflow) */
static inline bool u16_add_overflow(u16_t a, u16_t b, u16_t *result)
{
u16_t c = a + b;
*result = c;
return c < a;
}
static inline bool u32_add_overflow(u32_t a, u32_t b, u32_t *result)
{
u32_t c = a + b;
@ -73,6 +87,11 @@ static inline bool size_add_overflow(size_t a, size_t b, size_t *result)
#endif /* use_builtin(__builtin_add_overflow) */
#if use_builtin(__builtin_mul_overflow)
static inline bool u16_mul_overflow(u16_t a, u16_t b, u16_t *result)
{
return __builtin_mul_overflow(a, b, result);
}
static inline bool u32_mul_overflow(u32_t a, u32_t b, u32_t *result)
{
return __builtin_mul_overflow(a, b, result);
@ -88,6 +107,15 @@ static inline bool size_mul_overflow(size_t a, size_t b, size_t *result)
return __builtin_mul_overflow(a, b, result);
}
#else /* !use_builtin(__builtin_mul_overflow) */
static inline bool u16_mul_overflow(u16_t a, u16_t b, u16_t *result)
{
u16_t c = a * b;
*result = c;
return a != 0 && (c / a) != b;
}
static inline bool u32_mul_overflow(u32_t a, u32_t b, u32_t *result)
{
u32_t c = a * b;