re PR bootstrap/71816 (bootstrap broken on multiple targets)

2016-07-11  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/71816
	* tree-ssa-pre.c (compute_avail): Adjust alignment of ref rather
	than replacing all of its operands.

	* gcc.dg/torture/pr71816.c: New testcase.

From-SVN: r238208

gcc/ChangeLog

+2016-07-11  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/71816
+	* tree-ssa-pre.c (compute_avail): Adjust alignment of ref rather
+	than replacing all of its operands.
+
 2016-07-11  Alan Modra  <amodra@gmail.com>
 
 	* config/rs6000/rs6000.md (UNSPEC_DOLOOP): New unspec.

gcc/testsuite/ChangeLog

+2016-07-11  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/71816
+	* gcc.dg/torture/pr71816.c: New testcase.
+
 2016-07-09  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/71783

gcc/testsuite/gcc.dg/torture/pr71816.c

+/* { dg-do compile } */
+
+void *ext2fs_resize_mem_p;
+struct ext2_icount_el {
+    int ino;
+} * insert_icount_el_icount_1;
+int insert_icount_el_icount, insert_icount_el_new_size;
+void *memcpy();
+void *realloc();
+int ext2fs_resize_mem(void *p1) {
+    int size = 0;
+    memcpy(&ext2fs_resize_mem_p, p1, sizeof(ext2fs_resize_mem_p));
+    realloc(&ext2fs_resize_mem_p, size);
+    return 0;
+}
+struct ext2_icount_el *insert_icount_el() {
+    if (insert_icount_el_icount)
+      insert_icount_el_new_size = insert_icount_el_icount_1[0].ino;
+    ext2fs_resize_mem(&insert_icount_el_icount_1);
+    return 0;
+}

gcc/tree-ssa-pre.c

@@ -3791,13 +3791,9 @@ compute_avail (void)
 			   || ref1->opcode == MEM_REF)
 			  && (TYPE_ALIGN (ref1->type)
 			      > TYPE_ALIGN (ref2->type)))
-			{
-			  ref->operands.release ();
-			  ref->operands = operands;
-			  ref1 = ref2;
-			}
-		      else
-			operands.release ();
+			ref1->type
+			  = build_aligned_type (ref1->type,
+						TYPE_ALIGN (ref2->type));
 		      /* TBAA behavior is an obvious part so make sure
 		         that the hashtable one covers this as well
 			 by adjusting the ref alias set and its base.  */
@@ -3824,6 +3820,7 @@ compute_avail (void)
 			    ref1->op2 = fold_convert (ptr_type_node,
 						      ref1->op2);
 			}
+		      operands.release ();
 
 		      result = pre_expr_pool.allocate ();
 		      result->kind = REFERENCE;