[PATCH] middle-end/103033 - drop native_interpret_expr with .DEFERRED_INIT expansion

[Richard Biener]

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.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

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.
---
 gcc/internal-fn.c | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/gcc/internal-fn.c b/gcc/internal-fn.c
index fd6cb0995d9..0cba95411a6 100644
--- 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.  */
-- 
2.31.1