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| author | Paul Eggert <eggert@cs.ucla.edu> | 2011-10-07 09:42:32 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2011-10-07 09:42:32 -0700 |
| commit | 84e8e185cdabbe547cb2b724c2ca1014a73efcfc (patch) | |
| tree | 9ba0930c801764c187064c0decea5b165d395fbc /src/alloc.c | |
| parent | de0bde6284da06b603b578cc5d19002fd15f928d (diff) | |
* alloc.c: Add comment.
Diffstat (limited to 'src/alloc.c')
| -rw-r--r-- | src/alloc.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/src/alloc.c b/src/alloc.c index f4db3abbd93..09ef4b085df 100644 --- a/src/alloc.c +++ b/src/alloc.c @@ -4235,6 +4235,11 @@ mark_maybe_pointer (void *p) } +/* Alignment of Lisp_Object and pointer values. Use offsetof, as it + sometimes returns a smaller alignment than GCC's __alignof__ and + mark_memory might miss objects if __alignof__ were used. For + example, on x86 with WIDE_EMACS_INT, __alignof__ (Lisp_Object) is 8 + but GC_LISP_OBJECT_ALIGNMENT should be 4. */ #ifndef GC_LISP_OBJECT_ALIGNMENT # define GC_LISP_OBJECT_ALIGNMENT offsetof (struct {char a; Lisp_Object b;}, b) #endif |