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[Bug sanitizer/81148] UBSAN: two more false positives
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 02 Aug 2017 07:19:55 +0000
- Subject: [Bug sanitizer/81148] UBSAN: two more false positives
- Auto-submitted: auto-generated
- References: <bug-81148-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148
--- Comment #14 from Richard Biener <rguenth at gcc dot gnu.org> ---
Folding
-123 - (((long int) ~(x != 0) ^ 9223372036854775806) + 1)
results in split_tree of (((long int) ~(x != 0) ^ 9223372036854775806) + 1)
returning -((long int) ~(x != 0) ^ 9223372036854775806) and minus_lit1 == 1.
The bug is obviously negating of 'var'.
I don't see any way around handling var and con like lit, thus adding
minus_var and minus_con and appropriately using MINUS_EXPR when
associating.
Bah.