middle-end/103033 - drop native_interpret_expr with .DEFERRED_INIT expansion

This drops the use of native_interpret_expr which can fail even though
can_native_interpret_expr_p returns true in favor of simply folding
the VIEW_CONVERT_EXPR punning.

2021-11-03  Richard Biener  <rguenther@suse.de>

	PR middle-end/103033
	* internal-fn.c (expand_DEFERRED_INIT): Elide the
	native_interpret_expr path in favor of folding the
	VIEW_CONVERT_EXPR generated when punning the RHS.

diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index fd6cb0995d9cbe74a2676acbce5e4cb068d40021..0cba95411a63423484dda5b1251f47de24e926ba 100644 (file)
--- a/gcc/internal-fn.c
+++ b/gcc/internal-fn.c
@@ -3070,9 +3070,11 @@ expand_DEFERRED_INIT (internal_fn, gcall *stmt)
     }
   else
     {
-      /* If this variable is in a register use expand_assignment.  */
+      /* If this variable is in a register use expand_assignment.
+        For boolean scalars force zero-init.  */
       tree init;
-      if (tree_fits_uhwi_p (var_size)
+      if (TREE_CODE (TREE_TYPE (lhs)) != BOOLEAN_TYPE
+         && tree_fits_uhwi_p (var_size)
          && (init_type == AUTO_INIT_PATTERN
              || !is_gimple_reg_type (var_type))
          && int_mode_for_size (tree_to_uhwi (var_size) * BITS_PER_UNIT,
@@ -3082,21 +3084,16 @@ expand_DEFERRED_INIT (internal_fn, gcall *stmt)
          unsigned char *buf = (unsigned char *) xmalloc (total_bytes);
          memset (buf, (init_type == AUTO_INIT_PATTERN
                        ? INIT_PATTERN_VALUE : 0), total_bytes);
-         if (can_native_interpret_type_p (var_type))
-           init = native_interpret_expr (var_type, buf, total_bytes);
+         tree itype = build_nonstandard_integer_type
+                        (total_bytes * BITS_PER_UNIT, 1);
+         wide_int w = wi::from_buffer (buf, total_bytes);
+         init = wide_int_to_tree (itype, w);
+         /* Pun the LHS to make sure its type has constant size
+            unless it is an SSA name where that's already known.  */
+         if (TREE_CODE (lhs) != SSA_NAME)
+           lhs = build1 (VIEW_CONVERT_EXPR, itype, lhs);
          else
-           {
-             tree itype = build_nonstandard_integer_type
-                            (total_bytes * BITS_PER_UNIT, 1);
-             wide_int w = wi::from_buffer (buf, total_bytes);
-             init = wide_int_to_tree (itype, w);
-             /* Pun the LHS to make sure its type has constant size
-                unless it is an SSA name where that's already known.  */
-             if (TREE_CODE (lhs) != SSA_NAME)
-               lhs = build1 (VIEW_CONVERT_EXPR, itype, lhs);
-             else
-               init = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), init);
-           }
+           init = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (lhs), init);
        }
       else
        /* Use zero-init also for variable-length sizes.  */