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|
Boxed structure of BigInts
----> Info1 Pointer
| Pointer passed to BigNum package
| |
\/ \/
Info2 Size Integer ....
(size excludes info ptr & size field)
Unboxed (Compiler must place on pointer stack not data stack
Must also tell GC if it is in a register when GC invoked)
----> Info2 Size Integer
Info1:
SPEC_INFO_TABLE(Info1, BigNum_entry, 1, 1); (Min Size 2 ?)
Entering this returns the BigNum using agreed return convention
Info2:
DATA_INFO_TABLE(Info2, Dummy_entry);
This never actually entered -- just required for GC.
------------------------------------------------------------------------------
Boxed structure of BigInts (the alternative one)
Pointer passed to BigNum package
|
\/
----> Info Size Integer ....
(size excludes info ptr & size field)
Unboxed (Compiler must place on pointer stack not data stack
Must also tell GC if it is in a register when GC invoked)
Info:
DATA_INFO_TABLE(Info, BigNum_entry);
Entering this returns the BigNum using agreed return convention
Note that the Boxed and Unboxed representation are identical !!!
(unboxing represents evaluationhood, not pointerhood)
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