More precise determination of small data accesses (#220)

We can get linker errors for addresses of the form "symbol + offset"
where "symbol" is in the small data area and "offset" is large enough
to overflow the relative displacement from the SDA base register.

To avoid this, this commit enriches `C2C.atom_is_small_data`,
which is the implementation of `Asm.symbol_is_small_data` in the PPC port,
with a check that the offset is within the bounds of the symbol.
If it is not, `Asm.symbol_is_small_data` returns `false` and Asmgen produces
an absolute addressing instead of a SDA-relative addressing.

To implement the check, we record the sizes of symbols in the atom table,
just like we already record their alignments.

0 files changed, 0 insertions, 0 deletions