Re: Add VIEW_CONVERT_EXPR to operand_equal_p

[Jan Hubicka <hubicka@ucw.cz>]

Hi,
here is updated patch that applies changes suggested by Richard. I apologize
for the delay - the testing failed several times on gcc10.fsffrance.org for me
for out-of-memory errors (which are unrelated) and I was on the travel.

Bootstrapped/regtested x86_64-linux, OK?
 
 	* tree.c (verify_type): Verify that TYPE_MODE match
 	between TYPE_CANONICAL and type.
 	* expr.c (store_expr_with_bounds): Revert my previous change.
 	* expmed.c (store_bit_field_1): Revert prevoius change.
 	* gimple-expr.c (useless_type_conversion_p): Require TYPE_MODE
 	to match for all types.

Index: tree.c
===================================================================
--- tree.c	(revision 228933)
+++ tree.c	(working copy)
@@ -13344,6 +13344,14 @@ verify_type (const_tree t)
       error_found = true;
     }
 
+  if (COMPLETE_TYPE_P (t) && TYPE_CANONICAL (t)
+      && TYPE_MODE (t) != TYPE_MODE (TYPE_CANONICAL (t)))
+    {
+      error ("TYPE_MODE of TYPE_CANONICAL is not compatible");
+      debug_tree (ct);
+      error_found = true;
+    }
+
 
   /* Check various uses of TYPE_MINVAL.  */
   if (RECORD_OR_UNION_TYPE_P (t))
Index: expr.c
===================================================================
--- expr.c	(revision 228933)
+++ expr.c	(working copy)
@@ -5425,14 +5425,6 @@ store_expr_with_bounds (tree exp, rtx ta
     temp = convert_modes (GET_MODE (target), TYPE_MODE (TREE_TYPE (exp)),
 			  temp, TYPE_UNSIGNED (TREE_TYPE (exp)));
 
-  /* We allow move between structures of same size but different mode.
-     If source is in memory and the mode differs, simply change the memory.  */
-  if (GET_MODE (temp) == BLKmode && GET_MODE (target) != BLKmode)
-    {
-      gcc_assert (MEM_P (temp));
-      temp = adjust_address_nv (temp, GET_MODE (target), 0);
-    }
-
   /* If value was not generated in the target, store it there.
      Convert the value to TARGET's type first if necessary and emit the
      pending incrementations that have been queued when expanding EXP.
Index: expmed.c
===================================================================
--- expmed.c	(revision 228933)
+++ expmed.c	(working copy)
@@ -757,14 +757,6 @@ store_bit_field_1 (rtx str_rtx, unsigned
       }
   }
 
-  /* We allow move between structures of same size but different mode.
-     If source is in memory and the mode differs, simply change the memory.  */
-  if (GET_MODE (value) == BLKmode && GET_MODE (op0) != BLKmode)
-    {
-      gcc_assert (MEM_P (value));
-      value = adjust_address_nv (value, GET_MODE (op0), 0);
-    }
-
   /* Storing an lsb-aligned field in a register
      can be done with a movstrict instruction.  */
 
Index: gimple-expr.c
===================================================================
--- gimple-expr.c	(revision 228933)
+++ gimple-expr.c	(working copy)
@@ -87,10 +87,8 @@ useless_type_conversion_p (tree outer_ty
   if (inner_type == outer_type)
     return true;
 
-  /* Changes in machine mode are never useless conversions unless we
-     deal with aggregate types in which case we defer to later checks.  */
-  if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type)
-      && !AGGREGATE_TYPE_P (inner_type))
+  /* Changes in machine mode are never useless conversions unless.  */
+  if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type))
     return false;
 
   /* If both the inner and outer types are integral types, then the
@@ -270,10 +268,9 @@ useless_type_conversion_p (tree outer_ty
      use the types in move operations.  */
   else if (AGGREGATE_TYPE_P (inner_type)
 	   && TREE_CODE (inner_type) == TREE_CODE (outer_type))
-    return (!TYPE_SIZE (outer_type)
-	    || (TYPE_SIZE (inner_type)
-		&& operand_equal_p (TYPE_SIZE (inner_type),
-				    TYPE_SIZE (outer_type), 0)));
+    return (TYPE_MODE (outer_type) != BLKmode
+	    || operand_equal_p (TYPE_SIZE (inner_type),
+			        TYPE_SIZE (outer_type), 0));
 
   else if (TREE_CODE (inner_type) == OFFSET_TYPE
 	   && TREE_CODE (outer_type) == OFFSET_TYPE)