PR middle-end/90597: gcc_assert ICE in layout_type

This patch fixes the default implementation of TARGET_VECTOR_ALIGNMENT,
known as default_vector_alignment, using the same logic as my earlier
nvptx patch, as the ICE caused by TYPE_SIZE(type) being zero during
error handling in gcc.dg/attr-vector_size.c is common among backends,
and is known in bugzilla as PR middle-end/90597, apparently a recent
regression.

2020-09-01  Roger Sayle  <roger@nextmovesoftware.com>

gcc/ChangeLog:
	PR middle-end/90597
	* targhooks.c (default_vector_alignment): Return at least the
	GET_MODE_ALIGNMENT for the type's mode.

diff --git a/gcc/targhooks.c b/gcc/targhooks.c
index 0113c7b0ce2359a59709402b6942e9eebb4adfb9..da4805d284e53247d57764988a75613828d6bee7 100644 (file)
--- a/gcc/targhooks.c
+++ b/gcc/targhooks.c
@@ -1233,8 +1233,9 @@ default_vector_alignment (const_tree type)
   tree size = TYPE_SIZE (type);
   if (tree_fits_uhwi_p (size))
     align = tree_to_uhwi (size);
-
-  return align < MAX_OFILE_ALIGNMENT ? align : MAX_OFILE_ALIGNMENT;
+  if (align >= MAX_OFILE_ALIGNMENT)
+    return MAX_OFILE_ALIGNMENT;
+  return MAX (align, GET_MODE_ALIGNMENT (TYPE_MODE (type)));
 }
 
 /* The default implementation of