Fix handling of ICF_NOVOPS in ipa-modref

As shown in somewhat convoluted testcase, ipa-modref is mistreating
ECF_NOVOPS as "having no side effects".  This come from time when
modref cared only about memory accesses and thus it was possible to
shortcut on it.

This patch removes (hopefully) all those bad shortcuts.
Bootstrapped/regtested x86_64-linux, comitted.

gcc/ChangeLog:

	PR ipa/109985

	* ipa-modref.cc (modref_summary::useful_p): Fix handling of ECF_NOVOPS.
	(modref_access_analysis::process_fnspec): Likevise.
	(modref_access_analysis::analyze_call): Likevise.
	(propagate_unknown_call): Likevise.
	(modref_propagate_in_scc): Likevise.
	(modref_propagate_flags_in_scc): Likewise.
	(ipa_merge_modref_summary_after_inlining): Likewise.

(cherry picked from commit efcbe7b985e24ac002a863afd609c44a67761195)

diff --git a/gcc/ipa-modref.cc b/gcc/ipa-modref.cc
index bcd9b49fe63181f2ac89397812d6d65ec25e711b..1d954954786f5042cb21fd250ae12ea1b9468ac3 100644 (file)
--- a/gcc/ipa-modref.cc
+++ b/gcc/ipa-modref.cc
@@ -332,7 +332,7 @@ modref_summary::useful_p (int ecf_flags, bool check_flags)
   if (check_flags
       && remove_useless_eaf_flags (static_chain_flags, ecf_flags, false))
     return true;
-  if (ecf_flags & (ECF_CONST | ECF_NOVOPS))
+  if (ecf_flags & ECF_CONST)
     return ((!side_effects || !nondeterministic)
            && (ecf_flags & ECF_LOOPING_CONST_OR_PURE));
   if (loads && !loads->every_base)
@@ -1261,7 +1261,7 @@ modref_access_analysis::merge_call_side_effects
   int flags = gimple_call_flags (call);
 
   /* Nothing to do for non-looping cont functions.  */
-  if ((flags & (ECF_CONST | ECF_NOVOPS))
+  if ((flags & ECF_CONST)
       && !(flags & ECF_LOOPING_CONST_OR_PURE))
     return false;
 
@@ -1274,7 +1274,7 @@ modref_access_analysis::merge_call_side_effects
   /* Merge side effects and non-determinism.
      PURE/CONST flags makes functions deterministic and if there is
      no LOOPING_CONST_OR_PURE they also have no side effects.  */
-  if (!(flags & (ECF_CONST | ECF_NOVOPS | ECF_PURE))
+  if (!(flags & (ECF_CONST | ECF_PURE))
       || (flags & ECF_LOOPING_CONST_OR_PURE))
     {
       if (!m_summary->side_effects && callee_summary->side_effects)
@@ -1463,7 +1463,7 @@ modref_access_analysis::process_fnspec (gcall *call)
 
   /* PURE/CONST flags makes functions deterministic and if there is
      no LOOPING_CONST_OR_PURE they also have no side effects.  */
-  if (!(flags & (ECF_CONST | ECF_NOVOPS | ECF_PURE))
+  if (!(flags & (ECF_CONST | ECF_PURE))
       || (flags & ECF_LOOPING_CONST_OR_PURE)
       || (cfun->can_throw_non_call_exceptions
          && stmt_could_throw_p (cfun, call)))
@@ -1602,12 +1602,12 @@ modref_access_analysis::analyze_call (gcall *stmt)
       print_gimple_stmt (dump_file, stmt, 0);
     }
 
-  if ((flags & (ECF_CONST | ECF_NOVOPS))
+  if ((flags & ECF_CONST)
       && !(flags & ECF_LOOPING_CONST_OR_PURE))
     {
       if (dump_file)
        fprintf (dump_file,
-                " - ECF_CONST | ECF_NOVOPS, ignoring all stores and all loads "
+                " - ECF_CONST, ignoring all stores and all loads "
                 "except for args.\n");
       return;
     }
@@ -1622,7 +1622,13 @@ modref_access_analysis::analyze_call (gcall *stmt)
       if (dump_file)
        fprintf (dump_file, gimple_call_internal_p (stmt)
                 ? " - Internal call" : " - Indirect call.\n");
-      process_fnspec (stmt);
+      if (flags & ECF_NOVOPS)
+        {
+         set_side_effects ();
+         set_nondeterministic ();
+        }
+      else
+       process_fnspec (stmt);
       return;
     }
   /* We only need to handle internal calls in IPA mode.  */
@@ -4510,7 +4516,7 @@ propagate_unknown_call (cgraph_node *node,
       return changed;
     }
 
-  if (!(ecf_flags & (ECF_CONST | ECF_NOVOPS | ECF_PURE))
+  if (!(ecf_flags & (ECF_CONST | ECF_PURE))
       || (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
       || nontrivial_scc)
     {
@@ -4724,7 +4730,7 @@ modref_propagate_in_scc (cgraph_node *component_node)
              struct cgraph_node *callee;
 
              if (!callee_edge->inline_failed
-                || ((flags & (ECF_CONST | ECF_NOVOPS))
+                || ((flags & ECF_CONST)
                     && !(flags & ECF_LOOPING_CONST_OR_PURE)))
                continue;
 
@@ -5147,8 +5153,8 @@ modref_propagate_flags_in_scc (cgraph_node *component_node)
            {
              escape_summary *sum = escape_summaries->get (e);
 
-             if (!sum || (e->indirect_info->ecf_flags
-                          & (ECF_CONST | ECF_NOVOPS)))
+             if (!sum || ((e->indirect_info->ecf_flags & ECF_CONST)
+                 && !(e->indirect_info->ecf_flags & ECF_LOOPING_CONST_OR_PURE)))
                continue;
 
              changed |= modref_merge_call_site_flags
@@ -5173,8 +5179,8 @@ modref_propagate_flags_in_scc (cgraph_node *component_node)
              modref_summary_lto *callee_summary_lto = NULL;
              struct cgraph_node *callee;
 
-             if (ecf_flags & (ECF_CONST | ECF_NOVOPS)
-                 || !callee_edge->inline_failed)
+             if ((ecf_flags & ECF_CONST)
+                 && !(ecf_flags & ECF_LOOPING_CONST_OR_PURE))
                continue;
 
              /* Get the callee and its summary.  */
@@ -5272,7 +5278,7 @@ ipa_merge_modref_summary_after_inlining (cgraph_edge *edge)
 
   if (!callee_info && to_info)
     {
-      if (!(flags & (ECF_CONST | ECF_NOVOPS)))
+      if (!(flags & (ECF_CONST | ECF_PURE | ECF_NOVOPS)))
        to_info->loads->collapse ();
       if (!ignore_stores)
        to_info->stores->collapse ();
@@ -5287,7 +5293,7 @@ ipa_merge_modref_summary_after_inlining (cgraph_edge *edge)
   /* Merge side effects and non-determinism.
      PURE/CONST flags makes functions deterministic and if there is
      no LOOPING_CONST_OR_PURE they also have no side effects.  */
-  if (!(flags & (ECF_CONST | ECF_NOVOPS | ECF_PURE))
+  if (!(flags & (ECF_CONST | ECF_PURE))
       || (flags & ECF_LOOPING_CONST_OR_PURE))
     {
       if (to_info)