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| author | Yuichi Nishiwaki <[email protected]> | 2013-08-04 01:08:11 -0700 |
|---|---|---|
| committer | Yuichi Nishiwaki <[email protected]> | 2013-08-04 01:08:11 -0700 |
| commit | dd2ea59d61dad130a6811fffbd1817105b2f84f5 (patch) | |
| tree | b6cbb7e24cf15c01096641706725a8e13f6d9223 /include | |
| parent | 94a6d8380f460c87f89870d6b71db2f262eacaf6 (diff) | |
| download | mruby-dd2ea59d61dad130a6811fffbd1817105b2f84f5.tar.gz mruby-dd2ea59d61dad130a6811fffbd1817105b2f84f5.zip | |
add commentary to value representation
Diffstat (limited to 'include')
| -rw-r--r-- | include/mruby/value.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/mruby/value.h b/include/mruby/value.h index 48fca796d..c98028109 100644 --- a/include/mruby/value.h +++ b/include/mruby/value.h @@ -144,6 +144,14 @@ typedef struct mrb_value { }; } mrb_value; +/* value representation by nan-boxing: + * float : FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF FFFFFFFFFFFFFFFF + * object: 111111111111TTTT TTPPPPPPPPPPPPPP PPPPPPPPPPPPPPPP PPPPPPPPPPPPPPPP + * int : 1111111111110000 1000000000000000 IIIIIIIIIIIIIIII IIIIIIIIIIIIIIII + * sym : 1111111111110000 1010000000000000 SSSSSSSSSSSSSSSS SSSSSSSSSSSSSSSS + * In order to get enough bit size to save TT, all pointers are shifted 2 bits + * in the right direction. + */ #define mrb_tt(o) (((o).value.ttt & 0xfc000)>>14) #define mrb_mktt(tt) (0xfff00000|((tt)<<14)) #define mrb_type(o) ((uint32_t)0xfff00000 < (o).value.ttt ? mrb_tt(o) : MRB_TT_FLOAT) |