On 12/14/2017 12:22 PM, Qing Zhao wrote: > >> On Dec 14, 2017, at 2:05 AM, Richard Biener <rguent...@suse.de >> <mailto:rguent...@suse.de>> wrote: >> >> On Wed, 13 Dec 2017, Qing Zhao wrote: >> >>> Hi, >>> >>> I updated gimple-fold.c as you suggested, bootstrapped and re-tested >>> on both x86 and aarch64. no any issue. >>> >>> ==== >>> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c >>> index 353a46e..eb6a87a 100644 >>> --- a/gcc/gimple-fold.c >>> +++ b/gcc/gimple-fold.c >>> @@ -1323,6 +1323,19 @@ get_range_strlen (tree arg, tree length[2], >>> bitmap *visited, int type, >>> the array could have zero length. */ >>> *minlen = ssize_int (0); >>> } >>> + >>> + if (VAR_P (arg) >>> + && TREE_CODE (TREE_TYPE (arg)) == ARRAY_TYPE) >>> + { >>> + val = TYPE_SIZE_UNIT (TREE_TYPE (arg)); >>> + if (!val || TREE_CODE (val) != INTEGER_CST || integer_zerop (val)) >>> +return false; >>> + val = wide_int_to_tree (TREE_TYPE (val), >>> + wi::sub(wi::to_wide (val), 1)); >>> + /* Set the minimum size to zero since the string in >>> + the array could have zero length. */ >>> + *minlen = ssize_int (0); >>> + } >>> } >>> ==== >>> >>> I plan to commit the change very soon. >>> let me know if you have further comment. >> >> Looks good to me. > > thanks a lot for your review. > > committed the patch as revision 255654 > https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=255654 > > PR 79538 was filed against GCC7.0, So, I assume that this patch need to > be backported to GCC7 branch. > I will do the backporting to GCC7 later this week if there is no objection. We don't try to backport all fixes to the release branches -- we tend to focus more on regressions that apply to those releases and codegen correctness issues.
I'd think a missed warning isn't that important to backport. Jeff
