https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88398
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu.org
Blocks| |53947
--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Well, the main issue is that the loop has two exits which is something the
vectorizer doesn't support (with a hard check). Jakub explains why that is so.
You could change the loop to sth like
unsigned char *p = cur + pos;
int len = 0;
int diff_pos = __INT_MAX__;
while (++len != max)
if (p[len] != cur[len])
diff_pos = len < diff_pos ? len : diff_pos;
return cur[diff_pos];
which then runs into a limitation recently reported (two dependent
reductions not recognized).
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53947
[Bug 53947] [meta-bug] vectorizer missed-optimizations
