print/a ... (again!)

[Andrew Cagney <ac131313 at cygnus dot com>]

Hello,

I'm looking at a 64 bit MIPS debugging a 32 bit ISA (-mips2 -EB) and am
seeing:

  (gdb) p/a main+4
  $1 = 0xa0020290
  (gdb) print main + 4
  $5 = (int (*)()) 0xffffffffa0020290 <main+4>

notice how ``print/a'' doesn't know where main is.  Grubbing around in
printcmd.c I find:

    case 'a':
      {
        /* Truncate address to the size of a target pointer, avoiding
           shifts larger or equal than the width of a CORE_ADDR.  The
           local variable PTR_BIT stops the compiler reporting a shift
           overflow when it won't occure. */
        CORE_ADDR addr = unpack_pointer (type, valaddr);
        int ptr_bit = TARGET_PTR_BIT;
        if (ptr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT))
          addr &= ((CORE_ADDR) 1 << ptr_bit) - 1;
        print_address (addr, stream);
      }
      break;

the problem is that the mask strips off a significant part of the
address.  Commenting out that mask I get the behavour:

  (gdb) print main+4
  $2 = (int (*)()) 0xffffffffa0020290 <main+4>
  (gdb) print/a main+4
  $3 = 0xffffffffa0020290 <main+4>

which is definitly an improvement.  I'm going to have to go diging
around in the e-mail archives.  Anyone care to try to summarize the
rationale behind the mask?

	enjoy,
		Andrew