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Merge pull request #5882 from rmalizia44/master

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Add code block in boxing docs to better spacing
This commit is contained in:
Yukihiro "Matz" Matsumoto
2022-12-27 09:58:22 +09:00
committed by GitHub
parent fb34d9ee17 1614a88cb7
commit 02c576accf
1 changed files with 20 additions and 20 deletions
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doc/internal/boxing.md
+20 -20
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@@ -14,15 +14,15 @@ Some values (called immediate values, e.g. integers, booleans, symbols, etc.) ar
The Word boxing packing bit patterns are like following:
| Types | Bit Pattern |
|--------|-------------------------------------|
| object | xxxxxxxx xxxxxxxx xxxxxxxx xxxxx000 |
| fixnum | xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxx1 |
| nil | 00000000 00000000 00000000 00000000 |
| true | 00000000 00000000 00000000 00001100 |
| false | 00000000 00000000 00000000 00000100 |
| undef | 00000000 00000000 00000000 00010100 |
| symbol | xxxxxxxx xxxxxxxx xxxxxxxx xxxxxx10 |
| Types | Bit Pattern |
|--------|---------------------------------------|
| object | `xxxxxxxx xxxxxxxx xxxxxxxx xxxxx000` |
| fixnum | `xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxx1` |
| nil | `00000000 00000000 00000000 00000000` |
| true | `00000000 00000000 00000000 00001100` |
| false | `00000000 00000000 00000000 00000100` |
| undef | `00000000 00000000 00000000 00010100` |
| symbol | `xxxxxxxx xxxxxxxx xxxxxxxx xxxxxx10` |
On 64 bit platform (unless `MRB_WORDBOX_NO_FLOAT_TRUNCATE`), float values are also packed in the `mrb_value`. In that case, we drop least significant 2 bits from mantissa.
If you need full precision for floating-point numbers, define `MRB_WORDBOX_NO_FLOAT_TRUNCATE`.
@@ -33,17 +33,17 @@ NaN boxing packs the Ruby data in a floating-point numbers, which represent NaN
The NaN boxing packing bit patterns are like following:
| Types | Bit Pattern |
|--------|-------------------------------------------------------------------------|
| float | SEEEEEEE EEEEFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF |
| +/-inf | S1111111 11110000 00000000 00000000 00000000 00000000 00000000 00000000 |
| nan | 01111111 11111000 00000000 00000000 00000000 00000000 00000000 00000000 |
| fixnum | 01111111 11111001 00000000 00000000 IIIIIIII IIIIIIII IIIIIIII IIIIIIII |
| symbol | 01111111 11111110 00000000 00000000 SSSSSSSS SSSSSSSS SSSSSSSS SSSSSSSS |
| misc | 01111111 11111111 00000000 00000000 00000000 00000000 00TTTTTT 0000MMMM |
| object | 01111111 11111100 PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPP00 |
| ptr | 01111111 11111100 PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPP01 |
| nil | 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 |
| Types | Bit Pattern |
|--------|---------------------------------------------------------------------------|
| float | `SEEEEEEE EEEEFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF FFFFFFFF` |
| +/-inf | `S1111111 11110000 00000000 00000000 00000000 00000000 00000000 00000000` |
| nan | `01111111 11111000 00000000 00000000 00000000 00000000 00000000 00000000` |
| fixnum | `01111111 11111001 00000000 00000000 IIIIIIII IIIIIIII IIIIIIII IIIIIIII` |
| symbol | `01111111 11111110 00000000 00000000 SSSSSSSS SSSSSSSS SSSSSSSS SSSSSSSS` |
| misc | `01111111 11111111 00000000 00000000 00000000 00000000 00TTTTTT 0000MMMM` |
| object | `01111111 11111100 PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPP00` |
| ptr | `01111111 11111100 PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPPPP PPPPPP01` |
| nil | `00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000` |
The object values appear far more frequently than floating-point numbers, so we offset the value so that object pointers are unchanged. This technique is called "favor pointer"".