re PR middle-end/58956 (wrong code at -O1 and above (affecting gcc 4.6 to trunk))

	PR middle-end/58956
	PR middle-end/59470
	* gimple-walk.h (walk_stmt_load_store_addr_fn): New typedef.
	(walk_stmt_load_store_addr_ops, walk_stmt_load_store_ops): Use it
	for callback params.
	* gimple-walk.c (walk_stmt_load_store_ops): Likewise.
	(walk_stmt_load_store_addr_ops): Likewise.  Adjust all callback
	calls to supply the gimple operand containing the base tree
	as an extra argument.
	* tree-ssa-ter.c: Include gimple-walk.h.
	(find_ssaname, find_ssaname_in_store): New helper functions.
	(find_replaceable_in_bb): For calls or GIMPLE_ASM, only set
	same_root_var if USE is used somewhere in the stores of the stmt.
	* ipa-prop.c (visit_ref_for_mod_analysis): Remove name of the stmt
	argument and ATTRIBUTE_UNUSED, add another unnamed tree argument.
	* ipa-pure-const.c (check_load, check_store, check_ipa_load,
	check_ipa_store): Likewise.
	* gimple.c (gimple_ior_addresses_taken_1, check_loadstore): Likewise.
	* ipa-split.c (test_nonssa_use, mark_nonssa_use): Likewise.
	(verify_non_ssa_vars, visit_bb): Adjust their callers.
	* cfgexpand.c (add_scope_conflicts_1): Use
	walk_stmt_load_store_addr_fn type for visit variable.
	(visit_op, visit_conflict): Remove name of the stmt
	argument and ATTRIBUTE_UNUSED, add another unnamed tree argument.
	* tree-sra.c (asm_visit_addr): Likewise.  Remove name of the data
	argument and ATTRIBUTE_UNUSED.
	* cgraphbuild.c (mark_address, mark_load, mark_store): Add another
	unnamed tree argument.
	* gimple-ssa-isolate-paths.c (check_loadstore): Likewise.  Remove
	ATTRIBUTE_UNUSED from stmt parameter.

	* gcc.target/i386/pr59470.c: New test.

From-SVN: r206009

1 files changed, 46 insertions, 1 deletions

diff --git a/gcc/tree-ssa-ter.c b/gcc/tree-ssa-ter.c
index 22ae47b766b..cefe47c6d5f 100644
--- a/gcc/tree-ssa-ter.c
+++ b/gcc/tree-ssa-ter.c
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-ter.h"
 #include "tree-outof-ssa.h"
 #include "flags.h"
+#include "gimple-walk.h"
 
 
 /* Temporary Expression Replacement (TER)
@@ -554,6 +555,30 @@ mark_replaceable (temp_expr_table_p tab, tree var, bool more_replacing)
 }
 
 
+/* Helper function for find_ssaname_in_stores.  Called via walk_tree to
+   find a SSA_NAME DATA somewhere in *TP.  */
+
+static tree
+find_ssaname (tree *tp, int *walk_subtrees, void *data)
+{
+  tree var = (tree) data;
+  if (*tp == var)
+    return var;
+  else if (IS_TYPE_OR_DECL_P (*tp))
+    *walk_subtrees = 0;
+  return NULL_TREE;
+}
+
+/* Helper function for find_replaceable_in_bb.  Return true if SSA_NAME DATA
+   is used somewhere in T, which is a store in the statement.  Called via
+   walk_stmt_load_store_addr_ops.  */
+
+static bool
+find_ssaname_in_store (gimple, tree, tree t, void *data)
+{
+  return walk_tree (&t, find_ssaname, data, NULL) != NULL_TREE;
+}
+
 /* This function processes basic block BB, and looks for variables which can
    be replaced by their expressions.  Results are stored in the table TAB.  */
 
@@ -618,7 +643,27 @@ find_replaceable_in_bb (temp_expr_table_p tab, basic_block bb)
 		      && gimple_assign_single_p (def_stmt)
 		      && stmt_may_clobber_ref_p (stmt,
 						 gimple_assign_rhs1 (def_stmt)))
-		    same_root_var = true;
+		    {
+		      /* For calls, it is not a problem if USE is among
+			 call's arguments or say OBJ_TYPE_REF argument,
+			 all those necessarily need to be evaluated before
+			 the call that may clobber the memory.  But if
+			 LHS of the call refers to USE, expansion might
+			 evaluate it after the call, prevent TER in that
+			 case.
+			 For inline asm, allow TER of loads into input
+			 arguments, but disallow TER for USEs that occur
+			 somewhere in outputs.  */
+		      if (is_gimple_call (stmt)
+			  || gimple_code (stmt) == GIMPLE_ASM)
+			{
+			  if (walk_stmt_load_store_ops (stmt, use, NULL,
+							find_ssaname_in_store))
+			    same_root_var = true;
+			}
+		      else
+			same_root_var = true;
+		    }
 		}
 
 	      /* Mark expression as replaceable unless stmt is volatile, or the