[wide-int,1/8] Fix some off-by-one errors and bounds tests

This is the first of 8 patches from reading through the diff with mainline.
Some places had an off-by-one error on an index and some used "<= 0"
instead of ">= 0".

I think we should use MAX_BITSIZE_MODE_ANY_MODE rather than
MAX_BITSIZE_MODE_ANY_INT when handling floating-point modes.

Two hunks contain unrelated formatting fixes too.

Tested on x86_64-linux-gnu.  OK to install?

Thanks,
Richard

On Tue, Apr 22, 2014 at 9:45 PM, Richard Sandiford
<rdsandiford@googlemail.com> wrote:
> This is the first of 8 patches from reading through the diff with mainline.
> Some places had an off-by-one error on an index and some used "<= 0"
> instead of ">= 0".
>
> I think we should use MAX_BITSIZE_MODE_ANY_MODE rather than
> MAX_BITSIZE_MODE_ANY_INT when handling floating-point modes.
>
> Two hunks contain unrelated formatting fixes too.
>
> Tested on x86_64-linux-gnu.  OK to install?

Ok.

Thanks,
Richard.

> Thanks,
> Richard
>
> Index: gcc/c-family/c-ada-spec.c
> ===================================================================
> --- gcc/c-family/c-ada-spec.c   2014-04-22 20:31:10.632895953 +0100
> +++ gcc/c-family/c-ada-spec.c   2014-04-22 20:31:24.880998602 +0100
> @@ -2205,8 +2205,9 @@ dump_generic_ada_node (pretty_printer *b
>               val = -val;
>             }
>           sprintf (pp_buffer (buffer)->digit_buffer,
> -                  "16#%" HOST_WIDE_INT_PRINT "x", val.elt (val.get_len () - 1));
> -         for (i = val.get_len () - 2; i <= 0; i--)
> +                  "16#%" HOST_WIDE_INT_PRINT "x",
> +                  val.elt (val.get_len () - 1));
> +         for (i = val.get_len () - 2; i >= 0; i--)
>             sprintf (pp_buffer (buffer)->digit_buffer,
>                      HOST_WIDE_INT_PRINT_PADDED_HEX, val.elt (i));
>           pp_string (buffer, pp_buffer (buffer)->digit_buffer);
> Index: gcc/dbxout.c
> ===================================================================
> --- gcc/dbxout.c        2014-04-22 20:31:10.632895953 +0100
> +++ gcc/dbxout.c        2014-04-22 20:31:24.881998608 +0100
> @@ -720,7 +720,7 @@ stabstr_O (tree cst)
>      }
>
>    prec -= res_pres;
> -  for (i = prec - 3; i <= 0; i = i - 3)
> +  for (i = prec - 3; i >= 0; i = i - 3)
>      {
>        digit = wi::extract_uhwi (cst, i, 3);
>        stabstr_C ('0' + digit);
> Index: gcc/dwarf2out.c
> ===================================================================
> --- gcc/dwarf2out.c     2014-04-22 20:31:10.632895953 +0100
> +++ gcc/dwarf2out.c     2014-04-22 20:31:24.884998630 +0100
> @@ -1847,7 +1847,7 @@ output_loc_operands (dw_loc_descr_ref lo
>             int i;
>             int len = get_full_len (*val2->v.val_wide);
>             if (WORDS_BIG_ENDIAN)
> -             for (i = len; i >= 0; --i)
> +             for (i = len - 1; i >= 0; --i)
>                 dw2_asm_output_data (HOST_BITS_PER_WIDE_INT / HOST_BITS_PER_CHAR,
>                                      val2->v.val_wide->elt (i), NULL);
>             else
> @@ -2073,7 +2073,7 @@ output_loc_operands (dw_loc_descr_ref lo
>
>               dw2_asm_output_data (1, len * l, NULL);
>               if (WORDS_BIG_ENDIAN)
> -               for (i = len; i >= 0; --i)
> +               for (i = len - 1; i >= 0; --i)
>                   dw2_asm_output_data (l, val2->v.val_wide->elt (i), NULL);
>               else
>                 for (i = 0; i < len; ++i)
> @@ -5398,11 +5398,11 @@ print_die (dw_die_ref die, FILE *outfile
>             int i = a->dw_attr_val.v.val_wide->get_len ();
>             fprintf (outfile, "constant (");
>             gcc_assert (i > 0);
> -           if (a->dw_attr_val.v.val_wide->elt (i) == 0)
> +           if (a->dw_attr_val.v.val_wide->elt (i - 1) == 0)
>               fprintf (outfile, "0x");
>             fprintf (outfile, HOST_WIDE_INT_PRINT_HEX,
>                      a->dw_attr_val.v.val_wide->elt (--i));
> -           while (-- i >= 0)
> +           while (--i >= 0)
>               fprintf (outfile, HOST_WIDE_INT_PRINT_PADDED_HEX,
>                        a->dw_attr_val.v.val_wide->elt (i));
>             fprintf (outfile, ")");
> @@ -8723,7 +8723,7 @@ output_die (dw_die_ref die)
>                                    NULL);
>
>             if (WORDS_BIG_ENDIAN)
> -             for (i = len; i >= 0; --i)
> +             for (i = len - 1; i >= 0; --i)
>                 {
>                   dw2_asm_output_data (l, a->dw_attr_val.v.val_wide->elt (i),
>                                        name);
> Index: gcc/simplify-rtx.c
> ===================================================================
> --- gcc/simplify-rtx.c  2014-04-22 20:31:10.632895953 +0100
> +++ gcc/simplify-rtx.c  2014-04-22 20:31:24.884998630 +0100
> @@ -5395,7 +5395,7 @@ simplify_immed_subreg (enum machine_mode
>         case MODE_DECIMAL_FLOAT:
>           {
>             REAL_VALUE_TYPE r;
> -           long tmp[MAX_BITSIZE_MODE_ANY_INT / 32];
> +           long tmp[MAX_BITSIZE_MODE_ANY_MODE / 32];
>
>             /* real_from_target wants its input in words affected by
>                FLOAT_WORDS_BIG_ENDIAN.  However, we ignore this,