admin/mruby-mruby
1
0
Fork 0
mirror of https://github.com/mruby/mruby synced 2026-06-08 16:11:16 +00:00
Code Issues Packages Projects Releases Wiki Activity

add function for checked mrb_int subtraction

Browse Source
This commit is contained in:
cremno
2014-05-05 15:28:26 +02:00
parent 0f39304265
commit cf8df563c0
3 changed files with 14 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files
include/mruby/numeric.h
+10
View File
@@ -45,6 +45,16 @@ mrb_int_add_overflow(mrb_int augend, mrb_int addend, mrb_int *sum)
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_uint x = (mrb_uint)minuend;
mrb_uint y = (mrb_uint)subtrahend;
mrb_uint z = (mrb_uint)(x - y);
*difference = (mrb_int)z;
return !!(((x ^ z) & (~y ^ z)) & MRB_INT_OVERFLOW_MASK);
}
#undef MRB_INT_OVERFLOW_MASK
#undef mrb_uint
#undef MRB_UINT_MAKE