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qemu/host-utils: Add wrappers for overflow builtins

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These builtins came in with gcc 5 and clang 3.8, which are
slightly newer than our supported minimum compiler versions.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2020-11-06 17:42:36 -08:00
parent 5140d6be5e
commit cec07c0b61
1 changed files with 225 additions and 0 deletions
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225
include/qemu/host-utils.h
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@ -356,6 +356,231 @@ static inline uint64_t revbit64(uint64_t x)
#endif
}
/**
* sadd32_overflow - addition with overflow indication
* @x, @y: addends
* @ret: Output for sum
*
* Computes *@ret = @x + @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool sadd32_overflow(int32_t x, int32_t y, int32_t *ret)
{
#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5
return __builtin_add_overflow(x, y, ret);
#else
*ret = x + y;
return ((*ret ^ x) & ~(x ^ y)) < 0;
#endif
}
/**
* sadd64_overflow - addition with overflow indication
* @x, @y: addends
* @ret: Output for sum
*
* Computes *@ret = @x + @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool sadd64_overflow(int64_t x, int64_t y, int64_t *ret)
{
#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5
return __builtin_add_overflow(x, y, ret);
#else
*ret = x + y;
return ((*ret ^ x) & ~(x ^ y)) < 0;
#endif
}
/**
* uadd32_overflow - addition with overflow indication
* @x, @y: addends
* @ret: Output for sum
*
* Computes *@ret = @x + @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool uadd32_overflow(uint32_t x, uint32_t y, uint32_t *ret)
{
#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5
return __builtin_add_overflow(x, y, ret);
#else
*ret = x + y;
return *ret < x;
#endif
}
/**
* uadd64_overflow - addition with overflow indication
* @x, @y: addends
* @ret: Output for sum
*
* Computes *@ret = @x + @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool uadd64_overflow(uint64_t x, uint64_t y, uint64_t *ret)
{
#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5
return __builtin_add_overflow(x, y, ret);
#else
*ret = x + y;
return *ret < x;
#endif
}
/**
* ssub32_overflow - subtraction with overflow indication
* @x: Minuend
* @y: Subtrahend
* @ret: Output for difference
*
* Computes *@ret = @x - @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool ssub32_overflow(int32_t x, int32_t y, int32_t *ret)
{
#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5
return __builtin_sub_overflow(x, y, ret);
#else
*ret = x - y;
return ((*ret ^ x) & (x ^ y)) < 0;
#endif
}
/**
* ssub64_overflow - subtraction with overflow indication
* @x: Minuend
* @y: Subtrahend
* @ret: Output for sum
*
* Computes *@ret = @x - @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool ssub64_overflow(int64_t x, int64_t y, int64_t *ret)
{
#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5
return __builtin_sub_overflow(x, y, ret);
#else
*ret = x - y;
return ((*ret ^ x) & (x ^ y)) < 0;
#endif
}
/**
* usub32_overflow - subtraction with overflow indication
* @x: Minuend
* @y: Subtrahend
* @ret: Output for sum
*
* Computes *@ret = @x - @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool usub32_overflow(uint32_t x, uint32_t y, uint32_t *ret)
{
#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5
return __builtin_sub_overflow(x, y, ret);
#else
*ret = x - y;
return x < y;
#endif
}
/**
* usub64_overflow - subtraction with overflow indication
* @x: Minuend
* @y: Subtrahend
* @ret: Output for sum
*
* Computes *@ret = @x - @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool usub64_overflow(uint64_t x, uint64_t y, uint64_t *ret)
{
#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5
return __builtin_sub_overflow(x, y, ret);
#else
*ret = x - y;
return x < y;
#endif
}
/**
* smul32_overflow - multiplication with overflow indication
* @x, @y: Input multipliers
* @ret: Output for product
*
* Computes *@ret = @x * @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool smul32_overflow(int32_t x, int32_t y, int32_t *ret)
{
#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5
return __builtin_mul_overflow(x, y, ret);
#else
int64_t z = (int64_t)x * y;
*ret = z;
return *ret != z;
#endif
}
/**
* smul64_overflow - multiplication with overflow indication
* @x, @y: Input multipliers
* @ret: Output for product
*
* Computes *@ret = @x * @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool smul64_overflow(int64_t x, int64_t y, int64_t *ret)
{
#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5
return __builtin_mul_overflow(x, y, ret);
#else
uint64_t hi, lo;
muls64(&lo, &hi, x, y);
*ret = lo;
return hi != ((int64_t)lo >> 63);
#endif
}
/**
* umul32_overflow - multiplication with overflow indication
* @x, @y: Input multipliers
* @ret: Output for product
*
* Computes *@ret = @x * @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool umul32_overflow(uint32_t x, uint32_t y, uint32_t *ret)
{
#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5
return __builtin_mul_overflow(x, y, ret);
#else
uint64_t z = (uint64_t)x * y;
*ret = z;
return z > UINT32_MAX;
#endif
}
/**
* umul64_overflow - multiplication with overflow indication
* @x, @y: Input multipliers
* @ret: Output for product
*
* Computes *@ret = @x * @y, and returns true if and only if that
* value has been truncated.
*/
static inline bool umul64_overflow(uint64_t x, uint64_t y, uint64_t *ret)
{
#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5
return __builtin_mul_overflow(x, y, ret);
#else
uint64_t hi;
mulu64(ret, &hi, x, y);
return hi != 0;
#endif
}
/* Host type specific sizes of these routines. */
#if ULONG_MAX == UINT32_MAX