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Fix can_inline_edge_p and code marking calls unreachable


Hi,
this patch fixes several issues in the inliner.  First is the fact that
edge_set_predicate does not mark indirect and speculative edge as unreachable
correctly (found by my updated verification patch).
Other issue is that can_inline_edge_p was wrong in several ways.  It did
use DECL_STRUCT_FUNCTION to check cilk and non-call-exceptions.  THis does
not work with LTO.  I also misupdated Richard's code to avoid inlining across
optimization boundaries so it did not check anoything and finally I noticed
we need to also check flag_exceptions.  Inlining flag_exceptions function that
can throw into !flag_exceptions is leading to a wrong code.  This also made
me notice that we do not correctly maintain DECL_FUNCTION_PERSONALITY.
After we decide to inline function with DECL_FUNCTION_PERSONALITY into a function
without DECL_FUNCTION_PERSONALITY, the caller inherits callee's perosnality.
This is done by tree-inline but it is too late and won't prevent us to mix different
personalities within one caller that has no personality.

Bootstrapped/regtested x86_64-linux, will commit it after testing on firefox.

Honza

	* ipa-inline-analysis.c (redirect_to_unreachable): New function.
	(edge_set_predicate): Use it to mark unreachable edges.
	(inline_summary_t::duplicate): Remove unnecesary code.
	(remap_edge_summaries): Likewise.
	(dump_inline_summary): Report contains_cilk_spawn.
	(compute_inline_parameters): Compute contains_cilk_spawn.
	(inline_read_section, inline_write_summary): Stream
	contains_cilk_spawn.
	* ipa-inline.c (can_inline_edge_p): Do not tuch 
	DECL_STRUCT_FUNCTION that may not be available;
	use CIF_CILK_SPAWN for cilk; fix optimization attribute checks;
	remove check for callee_fun->can_throw_non_call_exceptions and
	replace it by optimization attribute check; check for flag_exceptions.
	* ipa-inline-transform.c (inline_call): Maintain
	DECL_FUNCTION_PERSONALITY
	* ipa-inline.h (inline_summary): Add contains_cilk_spawn.
Index: ipa-inline-analysis.c
===================================================================
--- ipa-inline-analysis.c	(revision 221682)
+++ ipa-inline-analysis.c	(working copy)
@@ -760,6 +760,31 @@ account_size_time (struct inline_summary
     }
 }
 
+/* We proved E to be unreachable, redirect it to __bultin_unreachable.  */
+
+static void
+redirect_to_unreachable (struct cgraph_edge *e)
+{
+  struct cgraph_node *callee = !e->inline_failed ? e->callee : NULL;
+  struct inline_edge_summary *es = inline_edge_summary (e);
+
+  if (e->speculative)
+    e->resolve_speculation (builtin_decl_implicit (BUILT_IN_UNREACHABLE));
+  if (!e->callee)
+    e->make_direct (cgraph_node::get_create
+		      (builtin_decl_implicit (BUILT_IN_UNREACHABLE)));
+  else
+    e->redirect_callee (cgraph_node::get_create
+			(builtin_decl_implicit (BUILT_IN_UNREACHABLE)));
+  e->inline_failed = CIF_UNREACHABLE;
+  e->frequency = 0;
+  e->count = 0;
+  es->call_stmt_size = 0;
+  es->call_stmt_time = 0;
+  if (callee)
+    callee->remove_symbol_and_inline_clones ();
+}
+
 /* Set predicate for edge E.  */
 
 static void
@@ -769,18 +794,8 @@ edge_set_predicate (struct cgraph_edge *
 
   /* If the edge is determined to be never executed, redirect it
      to BUILTIN_UNREACHABLE to save inliner from inlining into it.  */
-  if (predicate && false_predicate_p (predicate) && e->callee)
-    {
-      struct cgraph_node *callee = !e->inline_failed ? e->callee : NULL;
-
-      e->redirect_callee (cgraph_node::get_create
-			    (builtin_decl_implicit (BUILT_IN_UNREACHABLE)));
-      e->inline_failed = CIF_UNREACHABLE;
-      es->call_stmt_size = 0;
-      es->call_stmt_time = 0;
-      if (callee)
-	callee->remove_symbol_and_inline_clones ();
-    }
+  if (predicate && false_predicate_p (predicate))
+    redirect_to_unreachable (e);
   if (predicate && !true_predicate_p (predicate))
     {
       if (!es->predicate)
@@ -1228,10 +1243,7 @@ inline_summary_t::duplicate (cgraph_node
 							     info);
 	  if (false_predicate_p (&new_predicate)
 	      && !false_predicate_p (es->predicate))
-	    {
-	      optimized_out_size += es->call_stmt_size * INLINE_SIZE_SCALE;
-	      edge->frequency = 0;
-	    }
+	    optimized_out_size += es->call_stmt_size * INLINE_SIZE_SCALE;
 	  edge_set_predicate (edge, &new_predicate);
 	}
 
@@ -1250,10 +1262,7 @@ inline_summary_t::duplicate (cgraph_node
 							     info);
 	  if (false_predicate_p (&new_predicate)
 	      && !false_predicate_p (es->predicate))
-	    {
-	      optimized_out_size += es->call_stmt_size * INLINE_SIZE_SCALE;
-	      edge->frequency = 0;
-	    }
+	    optimized_out_size += es->call_stmt_size * INLINE_SIZE_SCALE;
 	  edge_set_predicate (edge, &new_predicate);
 	}
       remap_hint_predicate_after_duplication (&info->loop_iterations,
@@ -1441,6 +1450,8 @@ dump_inline_summary (FILE *f, struct cgr
 	fprintf (f, " always_inline");
       if (s->inlinable)
 	fprintf (f, " inlinable");
+      if (s->contains_cilk_spawn)
+	fprintf (f, " contains_cilk_spawn");
       fprintf (f, "\n  self time:       %i\n", s->self_time);
       fprintf (f, "  global time:     %i\n", s->time);
       fprintf (f, "  self size:       %i\n", s->self_size);
@@ -2925,6 +2936,8 @@ compute_inline_parameters (struct cgraph
   else
     info->inlinable = tree_inlinable_function_p (node->decl);
 
+  info->contains_cilk_spawn = fn_contains_cilk_spawn_p (cfun);
+
   /* Type attributes can use parameter indices to describe them.  */
   if (TYPE_ATTRIBUTES (TREE_TYPE (node->decl)))
     node->local.can_change_signature = false;
@@ -3487,14 +3500,6 @@ remap_edge_summaries (struct cgraph_edge
 				   es->predicate, operand_map, offset_map,
 				   possible_truths, toplev_predicate);
 	      edge_set_predicate (e, &p);
-	      /* TODO: We should remove the edge for code that will be
-	         optimized out, but we need to keep verifiers and tree-inline
-	         happy.  Make it cold for now.  */
-	      if (false_predicate_p (&p))
-		{
-		  e->count = 0;
-		  e->frequency = 0;
-		}
 	    }
 	  else
 	    edge_set_predicate (e, toplev_predicate);
@@ -3516,14 +3521,6 @@ remap_edge_summaries (struct cgraph_edge
 			       es->predicate, operand_map, offset_map,
 			       possible_truths, toplev_predicate);
 	  edge_set_predicate (e, &p);
-	  /* TODO: We should remove the edge for code that will be optimized
-	     out, but we need to keep verifiers and tree-inline happy.
-	     Make it cold for now.  */
-	  if (false_predicate_p (&p))
-	    {
-	      e->count = 0;
-	      e->frequency = 0;
-	    }
 	}
       else
 	edge_set_predicate (e, toplev_predicate);
@@ -4228,6 +4225,7 @@ inline_read_section (struct lto_file_dec
 
       bp = streamer_read_bitpack (&ib);
       info->inlinable = bp_unpack_value (&bp, 1);
+      info->contains_cilk_spawn = bp_unpack_value (&bp, 1);
 
       count2 = streamer_read_uhwi (&ib);
       gcc_assert (!info->conds);
@@ -4393,6 +4391,7 @@ inline_write_summary (void)
 	  streamer_write_hwi (ob, info->self_time);
 	  bp = bitpack_create (ob->main_stream);
 	  bp_pack_value (&bp, info->inlinable, 1);
+	  bp_pack_value (&bp, info->contains_cilk_spawn, 1);
 	  streamer_write_bitpack (&bp);
 	  streamer_write_uhwi (ob, vec_safe_length (info->conds));
 	  for (i = 0; vec_safe_iterate (info->conds, i, &c); i++)
Index: ipa-inline-transform.c
===================================================================
--- ipa-inline-transform.c	(revision 221682)
+++ ipa-inline-transform.c	(working copy)
@@ -322,6 +322,10 @@ inline_call (struct cgraph_edge *e, bool
   if (to->global.inlined_to)
     to = to->global.inlined_to;
 
+  if (DECL_FUNCTION_PERSONALITY (callee->decl))
+    DECL_FUNCTION_PERSONALITY (to->decl)
+      = DECL_FUNCTION_PERSONALITY (callee->decl);
+
   /* If aliases are involved, redirect edge to the actual destination and
      possibly remove the aliases.  */
   if (e->callee != callee)
Index: ipa-inline.h
===================================================================
--- ipa-inline.h	(revision 221682)
+++ ipa-inline.h	(working copy)
@@ -126,6 +126,9 @@ struct GTY(()) inline_summary
 
   /* False when there something makes inlining impossible (such as va_arg).  */
   unsigned inlinable : 1;
+  /* True when function contains cilk spawn (and thus we can not inline
+     into it).  */
+  unsigned contains_cilk_spawn : 1;
 
   /* Information about function that will result after applying all the
      inline decisions present in the callgraph.  Generally kept up to
Index: ipa-inline.c
===================================================================
--- ipa-inline.c	(revision 221682)
+++ ipa-inline.c	(working copy)
@@ -329,8 +329,6 @@ can_inline_edge_p (struct cgraph_edge *e
   tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller->decl);
   tree callee_tree
     = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->decl) : NULL;
-  struct function *caller_fun = caller->get_fun ();
-  struct function *callee_fun = callee ? callee->get_fun () : NULL;
 
   if (!callee->definition)
     {
@@ -342,12 +340,6 @@ can_inline_edge_p (struct cgraph_edge *e
       e->inline_failed = CIF_USES_COMDAT_LOCAL;
       inlinable = false;
     }
-  else if (!inline_summaries->get (callee)->inlinable
-	   || (caller_fun && fn_contains_cilk_spawn_p (caller_fun)))
-    {
-      e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
-      inlinable = false;
-    }
   else if (avail <= AVAIL_INTERPOSABLE)
     {
       e->inline_failed = CIF_OVERWRITABLE;
@@ -375,16 +367,6 @@ can_inline_edge_p (struct cgraph_edge *e
       e->inline_failed = CIF_UNSPECIFIED;
       inlinable = false;
     }
-  /* Don't inline if the callee can throw non-call exceptions but the
-     caller cannot.
-     FIXME: this is obviously wrong for LTO where STRUCT_FUNCTION is missing.
-     Move the flag into cgraph node or mirror it in the inline summary.  */
-  else if (callee_fun && callee_fun->can_throw_non_call_exceptions
-	   && !(caller_fun && caller_fun->can_throw_non_call_exceptions))
-    {
-      e->inline_failed = CIF_NON_CALL_EXCEPTIONS;
-      inlinable = false;
-    }
   /* Check compatibility of target optimization options.  */
   else if (!targetm.target_option.can_inline_p (caller->decl,
 						callee->decl))
@@ -392,6 +374,16 @@ can_inline_edge_p (struct cgraph_edge *e
       e->inline_failed = CIF_TARGET_OPTION_MISMATCH;
       inlinable = false;
     }
+  else if (!inline_summaries->get (callee)->inlinable)
+    {
+      e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
+      inlinable = false;
+    }
+  else if (inline_summaries->get (caller)->contains_cilk_spawn)
+    {
+      e->inline_failed = CIF_CILK_SPAWN;
+      inlinable = false;
+    }
   /* Don't inline a function with mismatched sanitization attributes. */
   else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
     {
@@ -416,38 +408,52 @@ can_inline_edge_p (struct cgraph_edge *e
       /* Strictly speaking only when the callee contains signed integer
          math where overflow is undefined.  */
       if ((opt_for_fn (caller->decl, flag_strict_overflow)
-	   != opt_for_fn (caller->decl, flag_strict_overflow))
+	   != opt_for_fn (callee->decl, flag_strict_overflow))
 	  || (opt_for_fn (caller->decl, flag_wrapv)
-	      != opt_for_fn (caller->decl, flag_wrapv))
+	      != opt_for_fn (callee->decl, flag_wrapv))
 	  || (opt_for_fn (caller->decl, flag_trapv)
-	      != opt_for_fn (caller->decl, flag_trapv))
+	      != opt_for_fn (callee->decl, flag_trapv))
 	  /* Strictly speaking only when the callee contains memory
 	     accesses that are not using alias-set zero anyway.  */
 	  || (opt_for_fn (caller->decl, flag_strict_aliasing)
-	      != opt_for_fn (caller->decl, flag_strict_aliasing))
+	      != opt_for_fn (callee->decl, flag_strict_aliasing))
 	  /* Strictly speaking only when the callee uses FP math.  */
 	  || (opt_for_fn (caller->decl, flag_rounding_math)
-	      != opt_for_fn (caller->decl, flag_rounding_math))
+	      != opt_for_fn (callee->decl, flag_rounding_math))
 	  || (opt_for_fn (caller->decl, flag_trapping_math)
-	      != opt_for_fn (caller->decl, flag_trapping_math))
+	      != opt_for_fn (callee->decl, flag_trapping_math))
 	  || (opt_for_fn (caller->decl, flag_unsafe_math_optimizations)
-	      != opt_for_fn (caller->decl, flag_unsafe_math_optimizations))
+	      != opt_for_fn (callee->decl, flag_unsafe_math_optimizations))
 	  || (opt_for_fn (caller->decl, flag_finite_math_only)
-	      != opt_for_fn (caller->decl, flag_finite_math_only))
+	      != opt_for_fn (callee->decl, flag_finite_math_only))
 	  || (opt_for_fn (caller->decl, flag_signaling_nans)
-	      != opt_for_fn (caller->decl, flag_signaling_nans))
+	      != opt_for_fn (callee->decl, flag_signaling_nans))
 	  || (opt_for_fn (caller->decl, flag_cx_limited_range)
-	      != opt_for_fn (caller->decl, flag_cx_limited_range))
+	      != opt_for_fn (callee->decl, flag_cx_limited_range))
 	  || (opt_for_fn (caller->decl, flag_signed_zeros)
-	      != opt_for_fn (caller->decl, flag_signed_zeros))
+	      != opt_for_fn (callee->decl, flag_signed_zeros))
 	  || (opt_for_fn (caller->decl, flag_associative_math)
-	      != opt_for_fn (caller->decl, flag_associative_math))
+	      != opt_for_fn (callee->decl, flag_associative_math))
 	  || (opt_for_fn (caller->decl, flag_reciprocal_math)
-	      != opt_for_fn (caller->decl, flag_reciprocal_math))
+	      != opt_for_fn (callee->decl, flag_reciprocal_math))
+	  /* We do not want to make code compiled with exceptions to be brought
+	     into a non-EH function unless we know that the callee does not
+	     throw.  This is tracked by DECL_FUNCTION_PERSONALITY.  */
+	  || (opt_for_fn (caller->decl, flag_non_call_exceptions)
+	      != opt_for_fn (callee->decl, flag_non_call_exceptions)
+	      /* TODO: We also may allow bringing !flag_non_call_exceptions
+		 to flag_non_call_exceptions function, but that may need
+		 extra work in tree-inline to add the extra EH edges.  */
+	      && (!opt_for_fn (callee->decl, flag_non_call_exceptions)
+		  || DECL_FUNCTION_PERSONALITY (callee->decl)))
+	  || (opt_for_fn (caller->decl, flag_exceptions)
+	      != opt_for_fn (callee->decl, flag_exceptions)
+	      && (!opt_for_fn (callee->decl, flag_exceptions)
+		  || DECL_FUNCTION_PERSONALITY (callee->decl)))
 	  /* Strictly speaking only when the callee contains function
 	     calls that may end up setting errno.  */
 	  || (opt_for_fn (caller->decl, flag_errno_math)
-	      != opt_for_fn (caller->decl, flag_errno_math))
+	      != opt_for_fn (callee->decl, flag_errno_math))
 	  /* When devirtualization is diabled for callee, it is not safe
 	     to inline it as we possibly mangled the type info.
 	     Allow early inlining of always inlines.  */


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