Re: [PATCH, PR 46984] Move thunk_delta from cgraph_indirect_call_info to cgraph_edge

[Jan Hubicka <hubicka at ucw dot cz>]

V/lt> Hi,
> 
> I made a stupid mistake when adding streaming of the new thunk_delta
> field in cgraph_indirect_call_info.  Without much thinking I simply
> added it to the existing streaming but forgot that the streaming deals
> with the analysis information, not decision information (for which
> ipa-prop has no streaming).  This is problem because thunk_delta is
> not an analysis thing but is determined and stored when making
> inlining and ipa-cp decisions and must be made available to the
> transformation phase.
> 
> I think that adding decision streaming to ipa-prop just for this
> purpose is not really a good idea (ipa-prop decisions are basically
> stored in call graph modifications and streamed along with call graph)
> and so I moved the field to the cgraph_edge and made it a
> HOST_WIDE_INT since we cannot stream trees along with the call graph.

> 
> I have bootstrapped and tested this on x86_64-linux without any
> problems.  OK for trunk?
> Index: icln/gcc/lto-cgraph.c
> ===================================================================
> --- icln.orig/gcc/lto-cgraph.c
> +++ icln/gcc/lto-cgraph.c
> @@ -278,6 +278,7 @@ lto_output_edge (struct lto_simple_outpu
>      }
>  
>    lto_output_sleb128_stream (ob->main_stream, edge->count);
> +  lto_output_sleb128_stream (ob->main_stream, edge->thunk_delta);
>  
>    bp = bitpack_create (ob->main_stream);
>    uid = (!gimple_has_body_p (edge->caller->decl)
> @@ -1210,6 +1211,7 @@ input_edge (struct lto_input_block *ib,
>    struct cgraph_edge *edge;
>    unsigned int stmt_id;
>    gcov_type count;
> +  HOST_WIDE_INT thunk_delta;
>    int freq;
>    unsigned int nest;
>    cgraph_inline_failed_t inline_failed;
> @@ -1230,6 +1232,7 @@ input_edge (struct lto_input_block *ib,
>      callee = NULL;
>  
>    count = (gcov_type) lto_input_sleb128 (ib);
> +  thunk_delta = lto_input_sleb128 (ib);
>  
>    bp = lto_input_bitpack (ib);
>    stmt_id = (unsigned int) bp_unpack_value (&bp, HOST_BITS_PER_INT);
> @@ -1243,6 +1246,7 @@ input_edge (struct lto_input_block *ib,
>    else
>      edge = cgraph_create_edge (caller, callee, NULL, count, freq, nest);
>  
> +  edge->thunk_delta = thunk_delta;
>    edge->indirect_inlining_edge = bp_unpack_value (&bp, 1);
>    edge->lto_stmt_uid = stmt_id;
>    edge->inline_failed = inline_failed;

You want to store this kind of info into cgraphopt section. (probably adding
output_egge_opt_summary function).
Consider patch pre-approved with that change.

Honza