[PATCH][19/n] Remove GENERIC stmt combining from SCCVN

[Richard Biener]

This moves some points-to related comparison simplification.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2015-07-24  Richard Biener  <rguenther@suse.de>

	* genmatch.c (add_operator): Allow SSA_NAME as predicate.
	* fold-const.c (fold_comparison): Move parameter does not
	alias &local simplification ...
	* match.pd: ... as a pattern here.

Index: gcc/genmatch.c
===================================================================
*** gcc/genmatch.c	(revision 226138)
--- gcc/genmatch.c	(working copy)
*************** add_operator (enum tree_code code, const
*** 395,401 ****
        /* To have INTEGER_CST and friends as "predicate operators".  */
        && strcmp (tcc, "tcc_constant") != 0
        /* And allow CONSTRUCTOR for vector initializers.  */
!       && !(code == CONSTRUCTOR))
      return;
    /* Treat ADDR_EXPR as atom, thus don't allow matching its operand.  */
    if (code == ADDR_EXPR)
--- 395,403 ----
        /* To have INTEGER_CST and friends as "predicate operators".  */
        && strcmp (tcc, "tcc_constant") != 0
        /* And allow CONSTRUCTOR for vector initializers.  */
!       && !(code == CONSTRUCTOR)
!       /* Allow SSA_NAME as predicate operator.  */
!       && !(code == SSA_NAME))
      return;
    /* Treat ADDR_EXPR as atom, thus don't allow matching its operand.  */
    if (code == ADDR_EXPR)
Index: gcc/fold-const.c
===================================================================
*** gcc/fold-const.c	(revision 226138)
--- gcc/fold-const.c	(working copy)
*************** fold_comparison (location_t loc, enum tr
*** 8467,8499 ****
  	    }
  	}
  
-       /* A local variable can never be pointed to by
-          the default SSA name of an incoming parameter.  */
-       if ((TREE_CODE (arg0) == ADDR_EXPR
-            && indirect_base0
-            && TREE_CODE (base0) == VAR_DECL
-            && auto_var_in_fn_p (base0, current_function_decl)
-            && !indirect_base1
-            && TREE_CODE (base1) == SSA_NAME
-            && SSA_NAME_IS_DEFAULT_DEF (base1)
- 	   && TREE_CODE (SSA_NAME_VAR (base1)) == PARM_DECL)
-           || (TREE_CODE (arg1) == ADDR_EXPR
-               && indirect_base1
-               && TREE_CODE (base1) == VAR_DECL
-               && auto_var_in_fn_p (base1, current_function_decl)
-               && !indirect_base0
-               && TREE_CODE (base0) == SSA_NAME
-               && SSA_NAME_IS_DEFAULT_DEF (base0)
- 	      && TREE_CODE (SSA_NAME_VAR (base0)) == PARM_DECL))
-         {
-           if (code == NE_EXPR)
-             return constant_boolean_node (1, type);
-           else if (code == EQ_EXPR)
-             return constant_boolean_node (0, type);
-         }
        /* If we have equivalent bases we might be able to simplify.  */
!       else if (indirect_base0 == indirect_base1
!                && operand_equal_p (base0, base1, 0))
  	{
  	  /* We can fold this expression to a constant if the non-constant
  	     offset parts are equal.  */
--- 8467,8475 ----
  	    }
  	}
  
        /* If we have equivalent bases we might be able to simplify.  */
!       if (indirect_base0 == indirect_base1
! 	  && operand_equal_p (base0, base1, 0))
  	{
  	  /* We can fold this expression to a constant if the non-constant
  	     offset parts are equal.  */
Index: gcc/match.pd
===================================================================
*** gcc/match.pd	(revision 226138)
--- gcc/match.pd	(working copy)
*************** (define_operator_list CBRT BUILT_IN_CBRT
*** 1743,1748 ****
--- 1743,1763 ----
  	   (if (cmp == GT_EXPR || cmp == GE_EXPR)
  	    { constant_boolean_node (above ? false : true, type); }))))))))))))
  
+ (for cmp (eq ne)
+  /* A local variable can never be pointed to by
+     the default SSA name of an incoming parameter.
+     SSA names are canonicalized to 2nd place.  */
+  (simplify
+   (cmp addr@0 SSA_NAME@1)
+   (if (SSA_NAME_IS_DEFAULT_DEF (@1)
+        && TREE_CODE (SSA_NAME_VAR (@1)) == PARM_DECL)
+    (with { tree base = get_base_address (TREE_OPERAND (@0, 0)); }
+     (if (TREE_CODE (base) == VAR_DECL
+          && auto_var_in_fn_p (base, current_function_decl))
+      (if (cmp == NE_EXPR)
+       { constant_boolean_node (true, type); }
+       { constant_boolean_node (false, type); }))))))
+ 
  /* Equality compare simplifications from fold_binary  */
  (for cmp (eq ne)