diff options
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/explow.c | 12 |
2 files changed, 17 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b3cf656..ac37bd2 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2003-04-07 Glen Nakamura <glen@imodulo.com> + + PR opt/8634 + * explow.c (maybe_set_unchanging): Don't flag non-static const + aggregate type initializers with RTX_UNCHANGING_P. + 2003-04-07 Richard Henderson <rth@redhat.com> PR opt/8634 diff --git a/gcc/explow.c b/gcc/explow.c index 50556e8..9ed034e 100644 --- a/gcc/explow.c +++ b/gcc/explow.c @@ -657,8 +657,18 @@ maybe_set_unchanging (ref, t) /* We can set RTX_UNCHANGING_P from TREE_READONLY for decls whose initialization is only executed once, or whose initializer always has the same value. Currently we simplify this to PARM_DECLs in the - first case, and decls with TREE_CONSTANT initializers in the second. */ + first case, and decls with TREE_CONSTANT initializers in the second. + + We cannot do this for non-static aggregates, because of the double + writes that can be generated by store_constructor, depending on the + contents of the initializer. Yes, this does eliminate a good fraction + of the number of uses of RTX_UNCHANGING_P for a language like Ada. + It also eliminates a good quantity of bugs. Let this be incentive to + eliminate RTX_UNCHANGING_P entirely in favour of a more reliable + solution, perhaps based on alias sets. */ + if ((TREE_READONLY (t) && DECL_P (t) + && (TREE_STATIC (t) || ! AGGREGATE_TYPE_P (TREE_TYPE (t))) && (TREE_CODE (t) == PARM_DECL || (DECL_INITIAL (t) && TREE_CONSTANT (DECL_INITIAL (t))))) || TREE_CODE_CLASS (TREE_CODE (t)) == 'c') |