No, the SV body isn't created at all for SVt_IV scalars.

A SV usually has a head block and a body block (that's in addition to any string buffer, etc). SVt_IV scalars, rather exceptionally, don't have a body. Or rather they have a body, but it's location overlaps the head so that it never needs to be allocated. 

5.12, 64 bit ints, 64 bit floats                    - - -+ <---+
                                                         :     |
                                                         : +04 |
     Usual SV head                      SVt_IV           :     |
--> +-----------------+            --> +-----------------+ +08 |
    | Pointer to body ------+          | Pointer to body ------+
+04 |                 |     |      +04 |                 | +0C
    |                 |     |          |                 |
+08 +-----------------+     |      +08 +-----------------+ +10
    | REFCNT          |     |          | REFCNT          |
+0C +-----------+-----+     |      +0C +-----------+-----+ +14
    | FLAGS     | SVt |     |          | FLAGS     | SVt |
+10 +-----------+-----+     |      +10 +-----------+-----+ +18
    | PV ---> +----------   |          | IV/UV           |
+14 |         |        ...  |      +14 |                 | +1C
    |         +----------   |          |                 |
+18 +-----------------+     |      +18 +-----------------+ +20
                            |
     Usual SV body          |
    +-----------------+ <---+
    | NV              |
    |                 | +04
    |                 |
    +-----------------+ +08
    | CUR             |
    |                 | +0C
    |                 |
    +-----------------+ +10
    | LEN             |
    |                 | +14
    |                 |
    +-----------------+ +18
    | IV/UV           |
    |                 | +1C
    |                 |
    +-----------------+ +20

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In reply to Re^7: Why is the size even bigger after pack? by ikegami
in thread Why is the size even bigger after pack? by PerlOnTheWay

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