diff options
| -rw-r--r-- | include/mruby/numeric.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/mruby/numeric.h b/include/mruby/numeric.h index b16c299a4..e4086487e 100644 --- a/include/mruby/numeric.h +++ b/include/mruby/numeric.h @@ -62,6 +62,12 @@ mrb_int_sub_overflow(mrb_int minuend, mrb_int subtrahend, mrb_int *difference) return __builtin_sub_overflow(minuend, subtrahend, difference) || WBCHK(*difference); } +static inline mrb_bool +mrb_int_mul_overflow(mrb_int multiplier, mrb_int multiplicand, mrb_int *product) +{ + return __builtin_mul_overflow(multiplier, multiplicand, product) || WBCHK(*product); +} + #undef WBCHK #else @@ -92,6 +98,35 @@ mrb_int_sub_overflow(mrb_int minuend, mrb_int subtrahend, mrb_int *difference) 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) +{ +#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 < MRB_INT_MAX / multiplier) return TRUE; + } + } + else { + if (multiplicand > 0) { + if (multiplier < MRB_INT_MAX / multiplicand) return TRUE; + } + else { + if (multiplier != 0 && multiplicand < MRB_INT_MAX / multiplier) return TRUE; + } + } + *product = multiplier * multiplicand; + return FALSE; +#endif +} + #undef MRB_INT_OVERFLOW_MASK #undef mrb_uint #undef MRB_UINT_MAKE |