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Change the fallback mrb_int_mul_overflow().

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Yukihiro "Matz" Matsumoto
2020-11-14 23:28:05 +09:00
parent 10c1c9d6f8
commit 2c6a5d3a77
1 changed files with 21 additions and 32 deletions
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include/mruby/numeric.h
+21 -32
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@@ -94,53 +94,42 @@ mrb_int_mul_overflow(mrb_int multiplier, mrb_int multiplicand, mrb_int *product)
#define MRB_UINT_MAKE(n) MRB_UINT_MAKE2(n)
#define mrb_uint MRB_UINT_MAKE(MRB_INT_BIT)
#define MRB_INT_OVERFLOW_MASK ((mrb_uint)1 << (MRB_INT_BIT - 1 - MRB_FIXNUM_SHIFT))
#define MRB_INT_OVERFLOW_MASK ((mrb_uint)1 << (MRB_INT_BIT - 1))
static inline mrb_bool
mrb_int_add_overflow(mrb_int augend, mrb_int addend, mrb_int *sum)
mrb_int_add_overflow(mrb_int a, mrb_int b, mrb_int *c)
{
mrb_uint x = (mrb_uint)augend;
mrb_uint y = (mrb_uint)addend;
mrb_uint x = (mrb_uint)a;
mrb_uint y = (mrb_uint)b;
mrb_uint z = (mrb_uint)(x + y);
*sum = (mrb_int)z;
*c = (mrb_int)z;
return !!(((x ^ z) & (y ^ z)) & MRB_INT_OVERFLOW_MASK);
}
static inline mrb_bool
mrb_int_sub_overflow(mrb_int minuend, mrb_int subtrahend, mrb_int *difference)
mrb_int_sub_overflow(mrb_int a, mrb_int b, mrb_int *c)
{
mrb_uint x = (mrb_uint)minuend;
mrb_uint y = (mrb_uint)subtrahend;
mrb_uint x = (mrb_uint)a;
mrb_uint y = (mrb_uint)b;
mrb_uint z = (mrb_uint)(x - y);
*difference = (mrb_int)z;
*c = (mrb_int)z;
return !!(((x ^ z) & (~y ^ z)) & MRB_INT_OVERFLOW_MASK);
}
static inline mrb_bool
mrb_int_mul_overflow(mrb_int multiplier, mrb_int multiplicand, mrb_int *product)
mrb_int_mul_overflow(mrb_int a, mrb_int b, mrb_int *c)
{
#if MRB_INT_BIT == 32
int64_t n = (int64_t)multiplier * multiplicand;
*product = (mrb_int)n;
return !FIXABLE(n);
#else
if (multiplier > 0) {
if (multiplicand > 0) {
if (multiplier > MRB_INT_MAX / multiplicand) return TRUE;
}
else if (multiplicand < 0) {
if (multiplicand < MRB_INT_MAX / multiplier) return TRUE;
}
}
else if (multiplier < 0) {
if (multiplicand > 0) {
if (multiplier < MRB_INT_MAX / multiplicand) return TRUE;
}
else if (multiplicand < 0) {
if (multiplier != 0 && multiplicand < MRB_INT_MAX / multiplier) return TRUE;
}
}
*product = multiplier * multiplicand;
#ifdef MRB_INT32
int64_t n = (int64_t)a * b;
*c = (mrb_int)n;
return n <= MRB_INT_MAX && n >= MRB_INT_MIN;
#else /* MRB_INT64 */
if (a > 0 && b > 0 && a > MRB_INT_MAX / b) return TRUE;
if (a < 0 && b > 0 && a < MRB_INT_MIN / b) return TRUE;
if (a > 0 && b < 0 && b < MRB_INT_MIN / a) return TRUE;
if (a < 0 && b < 0 && (a <= MRB_INT_MIN || b <= MRB_INT_MIN || -a > MRB_INT_MAX / -b))
return TRUE;
*c = a * b;
return FALSE;
#endif
}