2007-09-22  Pedro Alves  <pedro_alves@portugalmail.pt>

	* stabsread.c (read_huge_number): Remove special parsing of octal
	two's complement representation.  If just parsed a negative number
	in octal two's complement representation, sign extend the result
	to a long.

Index: stabsread.c
===================================================================
RCS file: /cvs/src/src/gdb/stabsread.c,v
retrieving revision 1.95
diff -u -p -r1.95 stabsread.c
--- stabsread.c	10 Aug 2007 22:08:22 -0000	1.95
+++ stabsread.c	22 Sep 2007 02:28:15 -0000
@@ -3737,32 +3737,9 @@ read_huge_number (char **pp, int end, in
     {
       if (n <= upper_limit)
         {
-          if (twos_complement_representation)
-            {
-              /* Octal, signed, twos complement representation. In this case,
-                 sn is the signed value, n is the corresponding absolute
-                 value. signed_bit is the position of the sign bit in the
-                 first three bits.  */
-              if (sn == 0)
-                {
-                  sign_bit = (twos_complement_bits % 3 + 2) % 3;
-                  sn = c - '0' - ((2 * (c - '0')) | (2 << sign_bit));
-                }
-              else
-                {
-                  sn *= radix;
-                  sn += c - '0';
-                }
-
-              if (sn < 0)
-                n = -sn;
-            }
-          else
-            {
-              /* unsigned representation */
-              n *= radix;
-              n += c - '0';		/* FIXME this overflows anyway */
-            }
+	  /* unsigned representation */
+	  n *= radix;
+	  n += c - '0';		/* FIXME this overflows anyway */
         }
       else
         overflow = 1;
@@ -3823,7 +3800,25 @@ read_huge_number (char **pp, int end, in
       if (bits)
 	*bits = 0;
       if (twos_complement_representation)
-        return sn;
+	{
+	  if (nbits == twos_complement_bits)
+	    {
+	      /* N is signed.  TWOS_COMPLEMENT_BITS may be less than
+		 what fits in a long.  Since we can't assume a host
+		 with two's complement long, extract the module value
+		 of N, and multiply it with -1.
+
+		 eg: with TWOS_COMPLEMENT_BITS == 16, and sizeof long == 32,
+		 0x00008111 => 0xffff7eef => 0x00007eef => 0xffff8111.  */
+
+	      unsigned long l = (unsigned long) n;
+	      l = ~l + 1;
+	      l &= (1L << twos_complement_bits) - 1;
+	      l *= -1;
+	      n = l;
+	    }
+	  return n;
+	}
       else
         return n * sign;
     }