Add loads/stores relative to static chain in ipa-modref

Adds tracking of accesses relative to static chain into modref
load/stores analysis.  This helps some Fortran benchmarks however it is still
quite limited.  One problem is that we never discover functions with nested
functions as const, pure or not accessing global memory because it contains
__builtin_dward_cfa call which we believe to be non-pure.

Bootstrapped/regtested x86_64-linux.  Plan to commit it tomorrow if there are
no complains and once periodic testers picks today modref changes.

Honza

gcc/ChangeLog:

	* ipa-modref-tree.h (enum modref_special_parms): New enum.
	(struct modref_access_node): update for special parms.
	(struct modref_ref_node): Likewise.
	(struct modref_parm_map): Likewise.
	(struct modref_tree): Likewise.
	* ipa-modref.c (dump_access): Likewise.
	(get_access): Detect static chain.
	(parm_map_for_arg): Take tree as arg instead of
	stmt and index.
	(merge_call_side_effects): Compute map for static chain.
	(process_fnspec): Update.
	(struct escape_point): Remove retslot_arg and static_chain_arg.
	(analyze_parms): Update.
	(compute_parm_map): Update.
	(propagate_unknown_call): Update.
	(modref_propagate_in_scc): Update.
	(modref_merge_call_site_flags): Update.
	(ipa_merge_modref_summary_after_inlining): Update.
	* tree-ssa-alias.c (modref_may_conflict): Handle static chain.
	* ipa-modref-tree.c (test_merge): Update.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/modref-12.c: New test.

1 files changed, 89 insertions, 63 deletions

diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
index 4e64ee5..4429bce 100644
--- a/gcc/ipa-modref.c
+++ b/gcc/ipa-modref.c
@@ -426,9 +426,14 @@ static void
 dump_access (modref_access_node *a, FILE *out)
 {
   fprintf (out, "          access:");
-  if (a->parm_index != -1)
+  if (a->parm_index != MODREF_UNKNOWN_PARM)
     {
-      fprintf (out, " Parm %i", a->parm_index);
+      if (a->parm_index >= 0)
+	fprintf (out, " Parm %i", a->parm_index);
+      else if (a->parm_index == MODREF_STATIC_CHAIN_PARM)
+	fprintf (out, " Static chain");
+      else
+	gcc_unreachable ();
       if (a->parm_offset_known)
 	{
 	  fprintf (out, " param offset:");
@@ -697,40 +702,40 @@ get_access (ao_ref *ref)
 
   base = ao_ref_base (ref);
   modref_access_node a = {ref->offset, ref->size, ref->max_size,
-			  0, -1, false, 0};
+			  0, MODREF_UNKNOWN_PARM, false, 0};
   if (TREE_CODE (base) == MEM_REF || TREE_CODE (base) == TARGET_MEM_REF)
     {
       tree memref = base;
       base = TREE_OPERAND (base, 0);
+
       if (TREE_CODE (base) == SSA_NAME
 	  && SSA_NAME_IS_DEFAULT_DEF (base)
 	  && TREE_CODE (SSA_NAME_VAR (base)) == PARM_DECL)
 	{
 	  a.parm_index = 0;
-	  for (tree t = DECL_ARGUMENTS (current_function_decl);
-	       t != SSA_NAME_VAR (base); t = DECL_CHAIN (t))
-	    {
-	      if (!t)
-		{
-		  a.parm_index = -1;
-		  break;
-		}
-	      a.parm_index++;
-	    }
-	  if (TREE_CODE (memref) == MEM_REF)
-	    {
-	      a.parm_offset_known
-		 = wi::to_poly_wide (TREE_OPERAND
-					 (memref, 1)).to_shwi (&a.parm_offset);
-	    }
+	  if (cfun->static_chain_decl
+	      && base == ssa_default_def (cfun, cfun->static_chain_decl))
+	    a.parm_index = MODREF_STATIC_CHAIN_PARM;
 	  else
-	    a.parm_offset_known = false;
+	    for (tree t = DECL_ARGUMENTS (current_function_decl);
+		 t != SSA_NAME_VAR (base); t = DECL_CHAIN (t))
+	      a.parm_index++;
+	}
+      else
+	a.parm_index = MODREF_UNKNOWN_PARM;
+
+      if (a.parm_index != MODREF_UNKNOWN_PARM
+	  && TREE_CODE (memref) == MEM_REF)
+	{
+	  a.parm_offset_known
+	     = wi::to_poly_wide (TREE_OPERAND
+				     (memref, 1)).to_shwi (&a.parm_offset);
 	}
       else
-	a.parm_index = -1;
+	a.parm_offset_known = false;
     }
   else
-    a.parm_index = -1;
+    a.parm_index = MODREF_UNKNOWN_PARM;
   return a;
 }
 
@@ -858,12 +863,11 @@ ignore_stores_p (tree caller, int flags)
   return false;
 }
 
-/* Determine parm_map for argument I of STMT.  */
+/* Determine parm_map for argument OP.  */
 
 modref_parm_map
-parm_map_for_arg (gimple *stmt, int i)
+parm_map_for_arg (tree op)
 {
-  tree op = gimple_call_arg (stmt, i);
   bool offset_known;
   poly_int64 offset;
   struct modref_parm_map parm_map;
@@ -882,7 +886,7 @@ parm_map_for_arg (gimple *stmt, int i)
 	{
 	  if (!t)
 	    {
-	      index = -1;
+	      index = MODREF_UNKNOWN_PARM;
 	      break;
 	    }
 	  index++;
@@ -892,9 +896,9 @@ parm_map_for_arg (gimple *stmt, int i)
       parm_map.parm_offset = offset;
     }
   else if (points_to_local_or_readonly_memory_p (op))
-    parm_map.parm_index = -2;
+    parm_map.parm_index = MODREF_LOCAL_MEMORY_PARM;
   else
-    parm_map.parm_index = -1;
+    parm_map.parm_index = MODREF_UNKNOWN_PARM;
   return parm_map;
 }
 
@@ -911,6 +915,7 @@ merge_call_side_effects (modref_summary *cur_summary,
 			 bool record_adjustments)
 {
   auto_vec <modref_parm_map, 32> parm_map;
+  modref_parm_map chain_map;
   bool changed = false;
 
   /* We can not safely optimize based on summary of callee if it does
@@ -931,7 +936,7 @@ merge_call_side_effects (modref_summary *cur_summary,
   parm_map.safe_grow_cleared (gimple_call_num_args (stmt), true);
   for (unsigned i = 0; i < gimple_call_num_args (stmt); i++)
     {
-      parm_map[i] = parm_map_for_arg (stmt, i);
+      parm_map[i] = parm_map_for_arg (gimple_call_arg (stmt, i));
       if (dump_file)
 	{
 	  fprintf (dump_file, " %i", parm_map[i].parm_index);
@@ -943,16 +948,30 @@ merge_call_side_effects (modref_summary *cur_summary,
 	    }
 	}
     }
+  if (gimple_call_chain (stmt))
+    {
+      chain_map = parm_map_for_arg (gimple_call_chain (stmt));
+      if (dump_file)
+	{
+	  fprintf (dump_file, "static chain %i", chain_map.parm_index);
+	  if (chain_map.parm_offset_known)
+	    {
+	      fprintf (dump_file, " offset:");
+	      print_dec ((poly_int64_pod)chain_map.parm_offset,
+			 dump_file, SIGNED);
+	    }
+	}
+    }
   if (dump_file)
     fprintf (dump_file, "\n");
 
   /* Merge with callee's summary.  */
   changed |= cur_summary->loads->merge (callee_summary->loads, &parm_map,
-					record_adjustments);
+					&chain_map, record_adjustments);
   if (!ignore_stores)
     {
       changed |= cur_summary->stores->merge (callee_summary->stores,
-					     &parm_map,
+					     &parm_map, &chain_map,
 					     record_adjustments);
       if (!cur_summary->writes_errno
 	  && callee_summary->writes_errno)
@@ -1078,11 +1097,12 @@ process_fnspec (modref_summary *cur_summary,
 	else if (!fnspec.arg_specified_p (i)
 		 || fnspec.arg_maybe_read_p (i))
 	  {
-	    modref_parm_map map = parm_map_for_arg (call, i);
+	    modref_parm_map map = parm_map_for_arg
+					(gimple_call_arg (call, i));
 
-	    if (map.parm_index == -2)
+	    if (map.parm_index == MODREF_LOCAL_MEMORY_PARM)
 	      continue;
-	    if (map.parm_index == -1)
+	    if (map.parm_index == MODREF_UNKNOWN_PARM)
 	      {
 		collapse_loads (cur_summary, cur_summary_lto);
 		break;
@@ -1113,11 +1133,12 @@ process_fnspec (modref_summary *cur_summary,
 	else if (!fnspec.arg_specified_p (i)
 		 || fnspec.arg_maybe_written_p (i))
 	  {
-	    modref_parm_map map = parm_map_for_arg (call, i);
+	    modref_parm_map map = parm_map_for_arg
+					 (gimple_call_arg (call, i));
 
-	    if (map.parm_index == -2)
+	    if (map.parm_index == MODREF_LOCAL_MEMORY_PARM)
 	      continue;
-	    if (map.parm_index == -1)
+	    if (map.parm_index == MODREF_UNKNOWN_PARM)
 	      {
 		collapse_stores (cur_summary, cur_summary_lto);
 		break;
@@ -1429,12 +1450,6 @@ deref_flags (int flags, bool ignore_stores)
 
 struct escape_point
 {
-  /* Extra hidden args we keep track of.  */
-  enum hidden_args
-  {
-    retslot_arg = -1,
-    static_chain_arg = -2
-  };
   /* Value escapes to this call.  */
   gcall *call;
   /* Argument it escapes to.  */
@@ -2410,7 +2425,7 @@ analyze_parms (modref_summary *summary, modref_summary_lto *summary_lto,
 	  if (summary_lto)
 	    summary_lto->retslot_flags = flags;
 	  eaf_analysis.record_escape_points (retslot,
-					     escape_point::retslot_arg, flags);
+					     MODREF_RETSLOT_PARM, flags);
 	}
     }
   if (static_chain)
@@ -2425,7 +2440,7 @@ analyze_parms (modref_summary *summary, modref_summary_lto *summary_lto,
 	  if (summary_lto)
 	    summary_lto->static_chain_flags = flags;
 	  eaf_analysis.record_escape_points (static_chain,
-					     escape_point::static_chain_arg,
+					     MODREF_STATIC_CHAIN_PARM,
 					     flags);
 	}
     }
@@ -3586,7 +3601,7 @@ compute_parm_map (cgraph_edge *callee_edge, vec<modref_parm_map> *parm_map)
 	{
 	  if (es && es->param[i].points_to_local_or_readonly_memory)
 	    {
-	      (*parm_map)[i].parm_index = -2;
+	      (*parm_map)[i].parm_index = MODREF_LOCAL_MEMORY_PARM;
 	      continue;
 	    }
 
@@ -3600,7 +3615,7 @@ compute_parm_map (cgraph_edge *callee_edge, vec<modref_parm_map> *parm_map)
 						 (callee_pi, i));
 	      if (cst && points_to_local_or_readonly_memory_p (cst))
 		{
-		  (*parm_map)[i].parm_index = -2;
+		  (*parm_map)[i].parm_index = MODREF_LOCAL_MEMORY_PARM;
 		  continue;
 		}
 	    }
@@ -3798,9 +3813,9 @@ propagate_unknown_call (cgraph_node *node,
 		   || fnspec.arg_maybe_read_p (i))
 	    {
 	      modref_parm_map map = parm_map[i];
-	      if (map.parm_index == -2)
+	      if (map.parm_index == MODREF_LOCAL_MEMORY_PARM)
 		continue;
-	      if (map.parm_index == -1)
+	      if (map.parm_index == MODREF_UNKNOWN_PARM)
 		{
 		  collapse_loads (cur_summary, cur_summary_lto);
 		  break;
@@ -3828,9 +3843,9 @@ propagate_unknown_call (cgraph_node *node,
 		   || fnspec.arg_maybe_written_p (i))
 	    {
 	      modref_parm_map map = parm_map[i];
-	      if (map.parm_index == -2)
+	      if (map.parm_index == MODREF_LOCAL_MEMORY_PARM)
 		continue;
-	      if (map.parm_index == -1)
+	      if (map.parm_index == MODREF_UNKNOWN_PARM)
 		{
 		  collapse_stores (cur_summary, cur_summary_lto);
 		  break;
@@ -4030,6 +4045,10 @@ modref_propagate_in_scc (cgraph_node *component_node)
 
 
 	      auto_vec <modref_parm_map, 32> parm_map;
+	      modref_parm_map chain_map;
+	      /* TODO: Once we get jump functions for static chains we could
+		 compute this.  */
+	      chain_map.parm_index = MODREF_UNKNOWN_PARM;
 
 	      compute_parm_map (callee_edge, &parm_map);
 
@@ -4037,12 +4056,13 @@ modref_propagate_in_scc (cgraph_node *component_node)
 	      if (callee_summary)
 		{
 		  changed |= cur_summary->loads->merge
-				  (callee_summary->loads, &parm_map, !first);
+				  (callee_summary->loads, &parm_map,
+				   &chain_map, !first);
 		  if (!ignore_stores)
 		    {
 		      changed |= cur_summary->stores->merge
 				      (callee_summary->stores, &parm_map,
-				       !first);
+				       &chain_map, !first);
 		      if (!cur_summary->writes_errno
 			  && callee_summary->writes_errno)
 			{
@@ -4055,12 +4075,12 @@ modref_propagate_in_scc (cgraph_node *component_node)
 		{
 		  changed |= cur_summary_lto->loads->merge
 				  (callee_summary_lto->loads, &parm_map,
-				   !first);
+				   &chain_map, !first);
 		  if (!ignore_stores)
 		    {
 		      changed |= cur_summary_lto->stores->merge
 				      (callee_summary_lto->stores, &parm_map,
-				       !first);
+				       &chain_map, !first);
 		      if (!cur_summary_lto->writes_errno
 			  && callee_summary_lto->writes_errno)
 			{
@@ -4223,9 +4243,9 @@ modref_merge_call_site_flags (escape_summary *sum,
       if (!(flags & EAF_UNUSED)
 	  && cur_summary && ee->parm_index < (int)cur_summary->arg_flags.length ())
 	{
-	  eaf_flags_t &f = ee->parm_index == escape_point::retslot_arg
+	  eaf_flags_t &f = ee->parm_index == MODREF_RETSLOT_PARM
 			   ? cur_summary->retslot_flags
-			   : ee->parm_index == escape_point::static_chain_arg
+			   : ee->parm_index == MODREF_STATIC_CHAIN_PARM
 			   ? cur_summary->static_chain_flags
 			   : cur_summary->arg_flags[ee->parm_index];
 	  if ((f & flags) != f)
@@ -4240,9 +4260,9 @@ modref_merge_call_site_flags (escape_summary *sum,
 	  && cur_summary_lto
 	  && ee->parm_index < (int)cur_summary_lto->arg_flags.length ())
 	{
-	  eaf_flags_t &f = ee->parm_index == escape_point::retslot_arg
+	  eaf_flags_t &f = ee->parm_index == MODREF_RETSLOT_PARM
 			   ? cur_summary_lto->retslot_flags
-			   : ee->parm_index == escape_point::static_chain_arg
+			   : ee->parm_index == MODREF_STATIC_CHAIN_PARM
 			   ? cur_summary_lto->static_chain_flags
 			   : cur_summary_lto->arg_flags[ee->parm_index];
 	  if ((f & flags_lto) != f)
@@ -4428,24 +4448,30 @@ ipa_merge_modref_summary_after_inlining (cgraph_edge *edge)
   if (callee_info || callee_info_lto)
     {
       auto_vec <modref_parm_map, 32> parm_map;
+      modref_parm_map chain_map;
+      /* TODO: Once we get jump functions for static chains we could
+	 compute this.  */
+      chain_map.parm_index = MODREF_UNKNOWN_PARM;
 
       compute_parm_map (edge, &parm_map);
 
       if (!ignore_stores)
 	{
 	  if (to_info && callee_info)
-	    to_info->stores->merge (callee_info->stores, &parm_map, false);
+	    to_info->stores->merge (callee_info->stores, &parm_map,
+				    &chain_map, false);
 	  if (to_info_lto && callee_info_lto)
 	    to_info_lto->stores->merge (callee_info_lto->stores, &parm_map,
-					false);
+					&chain_map, false);
 	}
       if (!(flags & (ECF_CONST | ECF_NOVOPS)))
 	{
 	  if (to_info && callee_info)
-	    to_info->loads->merge (callee_info->loads, &parm_map, false);
+	    to_info->loads->merge (callee_info->loads, &parm_map,
+				   &chain_map, false);
 	  if (to_info_lto && callee_info_lto)
 	    to_info_lto->loads->merge (callee_info_lto->loads, &parm_map,
-				       false);
+				       &chain_map, false);
 	}
     }