diff --git a/src/alloc.c b/src/alloc.c index 2e6399e7f8d..da0c3ad4b3e 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -2923,9 +2923,13 @@ set_next_vector (struct Lisp_Vector *v, struct Lisp_Vector *p) enum { - /* Alignment of struct Lisp_Vector objects. */ - vector_alignment = COMMON_MULTIPLE (FLEXALIGNOF (struct Lisp_Vector), - GCALIGNMENT), + /* Alignment of struct Lisp_Vector objects. Because pseudovectors + can contain any C type, align at least as strictly as + max_align_t. On x86 and x86-64 this can waste up to 8 bytes + for typical vectors, since alignof (max_align_t) is 16 but + typical vectors need only an alignment of 8. However, it is + not worth the hassle to avoid wasting those bytes. */ + vector_alignment = COMMON_MULTIPLE (alignof (max_align_t), GCALIGNMENT), /* Vector size requests are a multiple of this. */ roundup_size = COMMON_MULTIPLE (vector_alignment, word_size)