The following avoids a spurious BIT_INSERT_EXPR when rewriting
a decl into SSA form.
Bootstrap & regtest running on x86_64-unknown-linux-gnu.
Richard.
2019-11-02 Richard Biener <rguent...@suse.de>
PR tree-optimization/92645
* tree-ssa.c (execute_update_addresses_taken): Avoid representing
a full def of a vector via a BIT_INSERT_EXPR.
Index: gcc/tree-ssa.c
===================================================================
--- gcc/tree-ssa.c (revision 278893)
+++ gcc/tree-ssa.c (working copy)
@@ -1899,6 +1899,11 @@ execute_update_addresses_taken (void)
&& bitmap_bit_p (suitable_for_renaming, DECL_UID (sym))
&& VECTOR_TYPE_P (TREE_TYPE (sym))
&& TYPE_MODE (TREE_TYPE (sym)) != BLKmode
+ /* If it is a full replacement we can do better below. */
+ && maybe_ne (wi::to_poly_offset
+ (TYPE_SIZE_UNIT (TREE_TYPE (lhs))),
+ wi::to_poly_offset
+ (TYPE_SIZE_UNIT (TREE_TYPE (sym))))
&& known_ge (mem_ref_offset (lhs), 0)
&& known_gt (wi::to_poly_offset
(TYPE_SIZE_UNIT (TREE_TYPE (sym))),
