On Sun, 27 Oct 2019, Alexandre Oliva wrote:
> On Oct 26, 2019, Alexandre Oliva <ol...@adacore.com> wrote:
>
> > E.g., the reason we gather expanded calls rather than just use
> > cgraph_edges is that the latter would dump several "calls" that are
> > builtins expanded internally by the compiler, and would NOT dump other
> > ops that are expanded as (lib)calls.
>
> It occurred to me that we could reuse most cgraph edges and avoid
> duplicating them in the callees vec, namely those that aren't builtins
> or libcalls. Those that are builtins might or might not become actual
> calls, so we disregard the cgraph_edges and record them in the vec
> instead. Those that are libcalls (builtins in a different sense)
> introduced during expand are not even present in the cgraph edges, so we
> record them in the vec as well. Here's the patch that implements this.
>
> Regstrapped on x86_64-linux-gnu. Ok to install?
<...>
> --- a/gcc/common.opt
> +++ b/gcc/common.opt
> @@ -1091,6 +1091,14 @@ fbtr-bb-exclusive
> Common Ignore
> Does nothing. Preserved for backward compatibility.
>
> +fcallgraph-info
> +Common Report RejectNegative Var(flag_callgraph_info)
> Init(NO_CALLGRAPH_INFO);
> +Output callgraph information on a per-file basis
> +
> +fcallgraph-info=
> +Common Report RejectNegative Joined
> +Output callgraph information on a per-file basis with decorations
> +
> fcall-saved-
> Common Joined RejectNegative Var(common_deferred_options) Defer
> -fcall-saved-<register> Mark <register> as being preserved across
> functions.
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index 1407d019d1404..545b842eade71 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -583,8 +583,9 @@ Objective-C and Objective-C++ Dialects}.
> @item Developer Options
> @xref{Developer Options,,GCC Developer Options}.
> @gccoptlist{-d@var{letters} -dumpspecs -dumpmachine -dumpversion @gol
> --dumpfullversion -fchecking -fchecking=@var{n} -fdbg-cnt-list @gol
> --fdbg-cnt=@var{counter-value-list} @gol
> +-dumpfullversion -fcallgraph-info@r{[}=su,da@r{]}
> +-fchecking -fchecking=@var{n}
> +-fdbg-cnt-list @gol -fdbg-cnt=@var{counter-value-list} @gol
> -fdisable-ipa-@var{pass_name} @gol
> -fdisable-rtl-@var{pass_name} @gol
> -fdisable-rtl-@var{pass-name}=@var{range-list} @gol
> @@ -14533,6 +14534,18 @@ The files are created in the directory of the output
> file.
>
> @table @gcctabopt
>
> +@item -fcallgraph-info
> +@itemx -fcallgraph-info=@var{MARKERS}
> +@opindex fcallgraph-info
> +Makes the compiler output callgraph information for the program, on a
> +per-file basis. The information is generated in the common VCG format.
I guess you need to elaborate on 'per-file'. With LTO as far as I
understand you'll get the graph per LTRANS unit (did you check
where the output is generated?).
Is this mainly a debugging tool or does it serve a different purpose?
Otherwise OK.
Thanks,
Richard.
> +It can be decorated with additional, per-node and/or per-edge information,
> +if a list of comma-separated markers is additionally specified. When the
> +@code{su} marker is specified, the callgraph is decorated with stack usage
> +information; it is equivalent to @option{-fstack-usage}. When the @code{da}
> +marker is specified, the callgraph is decorated with information about
> +dynamically allocated objects.
