On 7/10/2026 6:55 PM, Andrea Pinski wrote:
Can you tell why it's restricted to the last full fold?
Restriction to the last full fold comes at the recommendation of Drea
Pinski in comment 6 on the PR
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92408#c6). Perhaps this
doesn't warrant inclusion in the test case? I'm impartial regardless.
Yes, my suggestion was just in case the folding gets in the way of the
strlen pass. I didn't know if the strlen pass would like the checking
done like `*a == 0` or `strlen(a) == 0`. And I didn't want to
introduce a regression due to that.
Makes sense as it's the kind of thing we've seen causing problems in the
past. We could drop the restriction and see if there's fallout, and if
so, how bad. In fact that's so trivial to do, I'll just fire it up in
my tester. It's got a while to go but it already flagged this on x86_64:
Tests that now fail, but worked before (2 tests):
gcc: gcc.dg/strlenopt-89.c scan-tree-dump-not strlen1 "a1\\] = 0;"
gcc: gcc.dg/strlenopt-89.c scan-tree-dump-times strlen1 "strlen \\(s_" 36
Given the nature of that test, I wouldn't be surprised if it's a
pervasive failure.
jeff
