Handle non-SSA arguments in ipa-inline-analysis better

[Jan Hubicka]

Hi,
this patch extends handling of non-SSA arguments to bultin_constant_p and
execution predicates.

Bootstrapped/regtested x86_64-linux, will commit it shortly.

Honza

        * ipa-inline-analysis.c (set_cond_stmt_execution_predicate): Allow
        handled components in parameter of builtin_constant_p.
        (will_be_nonconstant_predicate): Allow loads of non-SSA parameters.
Index: ipa-inline-analysis.c
===================================================================
--- ipa-inline-analysis.c       (revision 179046)
+++ ipa-inline-analysis.c       (working copy)
@@ -1202,6 +1202,7 @@ set_cond_stmt_execution_predicate (struc
   gimple set_stmt;
   tree op2;
   tree parm;
+  tree base;
 
   last = last_stmt (bb);
   if (!last
@@ -1252,7 +1253,8 @@ set_cond_stmt_execution_predicate (struc
       || gimple_call_num_args (set_stmt) != 1)
     return;
   op2 = gimple_call_arg (set_stmt, 0);
-  parm = unmodified_parm (set_stmt, op2);
+  base = get_base_address (op2);
+  parm = unmodified_parm (set_stmt, base ? base : op2);
   if (!parm)
     return;
   index = ipa_get_param_decl_index (info, parm);
@@ -1433,6 +1435,7 @@ will_be_nonconstant_predicate (struct ip
   ssa_op_iter iter;
   tree use;
   struct predicate op_non_const;
+  bool is_load;
 
   /* What statments might be optimized away
      when their arguments are constant
@@ -1443,11 +1446,29 @@ will_be_nonconstant_predicate (struct ip
       && gimple_code (stmt) != GIMPLE_SWITCH)
     return p;
 
-  /* Stores and loads will stay anyway.
-     TODO: Constant memory accesses could be handled here, too.  */
-  if (gimple_vuse (stmt))
+  /* Stores will stay anyway.  */
+  if (gimple_vdef (stmt))
     return p;
 
+  is_load = gimple_vuse (stmt) != NULL;
+
+  /* Loads can be optimized when the value is known.  */
+  if (is_load)
+    {
+      tree op = gimple_assign_rhs1 (stmt);
+      tree base = get_base_address (op);
+      tree parm;
+
+      gcc_assert (gimple_assign_single_p (stmt));
+      if (!base)
+       return p;
+      parm = unmodified_parm (stmt, base);
+      if (!parm )
+       return p;
+      if (ipa_get_param_decl_index (info, parm) < 0)
+       return p;
+    }
+
   /* See if we understand all operands before we start
      adding conditionals.  */
   FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
@@ -1466,6 +1487,15 @@ will_be_nonconstant_predicate (struct ip
       return p;
     }
   op_non_const = false_predicate ();
+  if (is_load)
+    {
+      tree parm = unmodified_parm
+                   (stmt, get_base_address (gimple_assign_rhs1 (stmt)));
+      p = add_condition (summary,
+                        ipa_get_param_decl_index (info, parm),
+                        IS_NOT_CONSTANT, NULL);
+      op_non_const = or_predicates (summary->conds, &p, &op_non_const);
+    }
   FOR_EACH_SSA_TREE_OPERAND (use, stmt, iter, SSA_OP_USE)
     {
       tree parm = unmodified_parm (stmt, use);