Re: fx_offset Population

[Ian Lance Taylor <ian at zembu dot com>]

Tracy Kuhrt <Tracy.Kuhrt@microchip.com> writes:

> In fix_new_internal, the fx_offset member of the fixP structure is
> populated with the offset, which is the value from the expressionS
> structure's'X_add_number.  The problem...
> 
> X_add_number is an offsetT (which in the end is a signed value).
> fx_offset is a valueT (which in the end is an unsigned value).
> When setting fx_offset to X_add_number, X_add_number is converted from a
> signed value to an unsigned value.  So in my test case, I have the
> expression . - 65536.  When the fixup is created -65536 is converted to
> an unsigned 4294901760.
> 
> What would be the harm of changing fx_offset to be an offsetT?

Probably none.

However, at the level of the assembler, the differences between signed
and unsigned numbers in relocation offsets are, as far as I know,
inconsequential.  I understand what you write above, but I don't
understand what the actual problem is.  Even if you change fx_offset,
the number is just going to wind up in the addend field of an arelent,
and that is also unsigned.

Can you explain the real problem?

Ian