[PATCH][LTO] Disable streamer debugging by default

[Steven Bosscher]

On Thu, Aug 20, 2009 at 6:13 PM, Richard Guenther<rguenther@suse.de> wrote:
> Index: gcc/lto-streamer-out.c
> ===================================================================
> *** gcc/lto-streamer-out.c      (revision 150943)
> --- gcc/lto-streamer-out.c      (working copy)
> *************** lto_output_tree_header (struct output_bl
> *** 1321,1332 ****
> --- 1321,1335 ----
>    output_uleb128 (ob, tree_size (expr));
>    output_sleb128 (ob, ix);
>
> +   /* The following will cause bootstrap miscomparisons.  Enable with care.  */
> + #ifdef LTO_STREAMER_DEBUG
>    /* This is used mainly for debugging purposes.  When the reader
>       and the writer do not agree on a streamed node, the pointer
>       value for EXPR can be used to track down the differences in
>       the debugger.  */
>    gcc_assert ((HOST_WIDEST_INT) (intptr_t) expr == (intptr_t) expr);
>    output_sleb128 (ob, (HOST_WIDEST_INT) (intptr_t) expr);
> + #endif
>

> Index: gcc/lto-streamer-in.c
> ===================================================================
> *** gcc/lto-streamer-in.c       (revision 150943)
> --- gcc/lto-streamer-in.c       (working copy)
(...)
> *************** lto_materialize_tree (struct lto_input_b
> *** 1722,1732 ****
> --- 1724,1736 ----
>    gcc_assert ((int) ix == ix);
>    *ix_p = (int) ix;
>
> + #ifdef LTO_STREAMER_DEBUG
>    /* Read the word representing the memory address for the tree
>       as it was written by the writer.  This is useful when
>       debugging differences between the writer and reader.  */
>    orig_address_in_writer = lto_input_sleb128 (ib);
>    gcc_assert ((intptr_t) orig_address_in_writer == orig_address_in_writer);
> + #endif
>
>    code = lto_tag_to_tree_code (tag);
>


Maybe write out / read in the sleb128 regardless of
LTO_STREAMER_DEBUG, but just not do the gcc_assert?  That way, you
should also be able to cmp  the output of an
LTO_STREAMER_DEBUG-enabled compiler with the output of an
LTO_STREAMER_DEBUG-disabled compiler?

Ciao!
Steven