Re: path for gdb/dwarf2read.c, support 16-bit targets in dwarf-2

[Jim Blandy <jimb at zwingli dot cygnus dot com>]

> I believe it is for an embedded 64 bit mips target (o64?) that is using
> 64 bit addresses within an elf32 executable.  (but the addresses are
> assumed to be 32bit sign extended).  Due to elf32, some debug info is 64
> bits, but other (symbol table?) is only 32 bits.

Right, that's what the comment for address_significant_bits said.  But
it doesn't address the real question.

> The mask has two effects:
> 
> 	o	it makes data from the two tables
> 		match.
> 
> 	o	it gives the user a better experience:
> 			(gdb) x/i 0x800000200
> 			0x800000200 <start>: ldi $1, 0
> 			(gdb) print &start
> 			$1 = 0x800000200
> 		vs
> 			x/i 0xffffffff800000200
> 			0xffffffff800000200 <start>: ldi $1, 0
> 			(gdb) print &start
> 			$2 = 0xffffffff800000200
> 		at the cost of carrying around wrong
> 		information and complicating the target.

But which is the correct address --- 0x0000000080000200, or
                                     0xffffffff80000200?