[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 Richard Biener changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|---

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #17 from Aldy Hernandez --- Author: aldyh Date: Wed Sep 13 16:25:51 2017 New Revision: 252277 URL: https://gcc.gnu.org/viewcvs?rev=252277=gcc=rev Log: 2017-08-03 Richard Biener PR middle-end/81148

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #16 from Richard Biener --- Author: rguenth Date: Thu Aug 3 11:52:00 2017 New Revision: 250853 URL: https://gcc.gnu.org/viewcvs?rev=250853=gcc=rev Log: 2017-08-03 Richard Biener PR middle-end/81148

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #15 from Marek Polacek --- My other idea was to pass bool ok to split_tree and if it sees that it cannot negate_expr something, set it to false, so that we don't change the expression after split_tree has been called. But if it

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #14 from Richard Biener --- 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

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #13 from Richard Biener --- C/C++ testcase: int x = -106; int main() { // -123 - (0x8000 - -1) return (-123 - ((9223372036854775806 ^ ~(x && 1)) - -1)) == 0; }

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 Richard Biener changed: What|Removed |Added Assignee|mpolacek at gcc dot gnu.org|rguenth at gcc dot gnu.org ---

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #11 from Marek Polacek --- That causes miscompiled cc1plus. Richi, any ideas?

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #10 from Marek Polacek --- It should've been --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -874,9 +874,24 @@ split_tree (location_t loc, tree in, tree type, enum tree_code code, } if (var) { - /* Convert to

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #9 from Marek Polacek --- Except that isn't really correct yet...

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #8 from Marek Polacek --- Seems like we need something similar to --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -874,9 +874,23 @@ split_tree (location_t loc, tree in, tree type, enum tree_code code, } if (var) { -

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #7 from Marek Polacek --- So were in "associate:", where lit0 = -123 lit1 = -1 which is associated to lit0 = -124 and var0 = null var1 = -((long int) ~(x != 0) ^ 9223372036854775806) which is associated to var0 = -((long int) ~(x !=

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #6 from Marek Polacek --- We basically have -123 - (LONG_MIN + 1) but it's being folded to -LONG_MIN + -124 which is of course not correct.

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #5 from Marek Polacek --- It's the (flag_sanitize & SANITIZE_SI_OVERFLOW) == 0 check in fold_negate_expr_1 that makes the difference w/ and w/o ubsan.

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #4 from Marek Polacek --- Started with commit 69693ea7b7ed45a12cbd505b2a66257fd4e81669 Author: rguenth Date: Fri Jun 26 10:59:27 2015 + 2015-06-26 Richard Biener

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #3 from Richard Biener --- Tomorrow, unless Marek beats me.

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 --- Comment #2 from Richard Biener --- w/o ubsan we fold this all the way to one. With ubsan we fold it as bool a = -((long int) ~(x != 0) ^ 9223372036854775806) + -124 != 0; so there's some stupid TYPE_OVERFLOW_SANITIZED check in the way

[Bug sanitizer/81148] UBSAN: two more false positives

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81148 Marek Polacek changed: What|Removed |Added Status|UNCONFIRMED |ASSIGNED Last reconfirmed|