introduce -fcallgraph-info option

[Alexandre Oliva]

On Nov  6, 2019, Alexandre Oliva <oliva@adacore.com> wrote:

> 	(CALLEE_FROM_CGRAPH_P): New.
> 	(dump_final_callee_vcg, dump_final_node_vcg): New.

I goofed in the testing of this last-minute change.  It only works with
optimization disabled.  With any optimization enabled,
pass_remove_cgraph_callee_edges runs first thing in
pass_all_optimizations{,_g} without a subsequent
pass_rebuild_cgraph_edges.  This release takes place long before we'd
even know which calls make to expand, and thus to the callgraph-info
expected output.

It has just occurred to me that I could retain the logic but make it
conditional on !optimize, but that would be error prone (AFAICT there's
no reason why we don't release callees early without optimization) and
probably not worth it.


drop attempt to reuse cgraph callees for -fcallgraph-info

The information in cgraph callees is released long before we get to
the point in which -fcallgraph-info edges are dumped, or even
expanded.  It doesn't make sense to retain it longer: the edges
created for -fcallgraph-info are much smaller, and they don't even
coexist, so not even peak use grows.

Regstrapped on x86_64-linux-gnu.  Ok to install?


for  gcc/ChangeLog

	* function.h (CALLEE_FROM_CGRAPH_P): Remove.
	* function.c (record_final_call): Record even calls that might
	have been in the cgraph.
	* toplev.c (dump_final_node_vcg): Skip iteration over cgraph
	callees.
---
 gcc/function.c |    3 ---
 gcc/function.h |    5 +----
 gcc/toplev.c   |    8 --------
 3 files changed, 1 insertion(+), 15 deletions(-)

diff --git a/gcc/function.c b/gcc/function.c
index 1fe956b..2534c92 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -6406,9 +6406,6 @@ rest_of_handle_thread_prologue_and_epilogue (void)
 void
 record_final_call (tree callee, location_t location)
 {
-  if (!callee || CALLEE_FROM_CGRAPH_P (callee))
-    return;
-
   struct callinfo_callee datum = { location, callee };
   vec_safe_push (cfun->su->callees, datum);
 }
diff --git a/gcc/function.h b/gcc/function.h
index 14794c4..beb5c7d 100644
--- a/gcc/function.h
+++ b/gcc/function.h
@@ -192,15 +192,12 @@ public:
   poly_int64 length;
 };
 
-/* Describe emitted builtin calls for -fcallgraph-info.  Those that
-   are not builtin are taken from cgraph edges.  */
+/* Describe emitted calls for -fcallgraph-info.  */
 struct GTY(()) callinfo_callee
 {
   location_t location;
   tree decl;
 };
-#define CALLEE_FROM_CGRAPH_P(T)				\
-  (!fndecl_built_in_p (T) && !DECL_IS_BUILTIN (T))
 
 /* Describe dynamic allocation for -fcallgraph-info=da.  */
 struct GTY(()) callinfo_dalloc
diff --git a/gcc/toplev.c b/gcc/toplev.c
index d4583ba..3b9f9ee 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1093,14 +1093,6 @@ dump_final_node_vcg (FILE *f)
     dump_final_callee_vcg (f, c->location, c->decl);
   vec_free (cfun->su->callees);
   cfun->su->callees = NULL;
-
-  cgraph_node *cnode = cgraph_node::get (current_function_decl);
-  for (cgraph_edge *e = cnode->callees; e; e = e->next_callee)
-    if (CALLEE_FROM_CGRAPH_P (e->callee->decl))
-      dump_final_callee_vcg (f, gimple_location (e->call_stmt),
-			     e->callee->decl);
-  for (cgraph_edge *e = cnode->indirect_calls; e; e = e->next_callee)
-    dump_final_callee_vcg (f, gimple_location (e->call_stmt), NULL);
 }
 
 /* Output stack usage and callgraph info, as requested.  */




-- 
Alexandre Oliva, freedom fighter   he/him   https://FSFLA.org/blogs/lxo
Free Software Evangelist           Stallman was right, but he's left :(
GNU Toolchain Engineer    FSMatrix: It was he who freed the first of us
FSF & FSFLA board member                The Savior shall return (true);