Previously, the linker gave an error if the relative displacement was more than + or - 32 KB. But 2-byte RELEXPR records are typically used for the operand of the BRL instruction, and since its address calculation wraps around within the program bank, it can effectively address + or - 64KB (i.e. any location within the program bank). Similar reasoning applies to PER, the other instruction using long relative addressing.
This would give an error in code like the following:
bigbrl start
brl later
ds 33000 ; realistic examples would have actual code here
later rtl
end
(This currently also gives an assembler error due to similar logic in ORCA/M, but the output file can be linked anyway.)
This issue can affect very large functions compiled with ORCA/C or ORCA/Pascal, which may sometimes have branches that go more than 32 KB forward or back.
This enables the linker to work correctly with object files with either extension case (or a mix), so it can work with objects from any of the ORCA languages even on a case-sensitive filesystem.
If two object files differ only in the case of their extension, the one with the lower-case extension will be used, and the one with the upper-case extension will be ignored.
