[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Richard Biener changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|---

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Bug 66313 depends on bug 81082, which changed state. Bug 81082 Summary: [8 Regression] Failure to vectorise after reassociating index computation https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81082 What|Removed

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Bug 66313 depends on bug 81554, which changed state. Bug 81554 Summary: [8 Regression] 25% performance regression in Himeno benchmark https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81554 What|Removed |Added

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Bug 66313 depends on bug 81203, which changed state. Bug 81203 Summary: [8 Regression] tail recursion: internal compiler error: verify_ssa failed https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81203 What|Removed

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Bug 66313 depends on bug 80948, which changed state. Bug 80948 Summary: [8 regression] test case gcc.dg/torture/pr68017.c fails with ICE starting with r248771 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80948 What|Removed

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Richard Biener changed: What|Removed |Added Known to work||8.0 Known to fail|

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #22 from Richard Biener --- Author: rguenth Date: Thu Jun 1 08:05:24 2017 New Revision: 248771 URL: https://gcc.gnu.org/viewcvs?rev=248771=gcc=rev Log: 2017-06-01 Richard Biener PR middle-end/66313

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #20 from Dmitry Babokin --- I've created #80932 for c1*(c2*v1-c3*v2)=>c1*c2*v1-c1*c3*v2 issue. --- Comment #21 from Dmitry Babokin --- I've created #80932 for c1*(c2*v1-c3*v2)=>c1*c2*v1-c1*c3*v2 issue.

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #20 from Dmitry Babokin --- I've created #80932 for c1*(c2*v1-c3*v2)=>c1*c2*v1-c1*c3*v2 issue. --- Comment #21 from Dmitry Babokin --- I've created #80932 for c1*(c2*v1-c3*v2)=>c1*c2*v1-c1*c3*v2 issue.

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #19 from Richard Biener --- Created attachment 41441 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41441=edit patch Patch I am testing, I finally managed to convince tailrecursion optimization to handle the case in

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #18 from Richard Biener --- (In reply to Dmitry Babokin from comment #16) > Here's another test case with a contrary example, where a variable gets > pulled into the braces and it also causes false positive. Transformation is: >

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #17 from Dmitry Babokin --- Any chances for the fix for this bug? Looks like this one stands as a last obstacle to claim UBSAN in GCC fully functional. I still see quite a few errors, but looks like all of them are attributed to

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #16 from Dmitry Babokin --- Here's another test case with a contrary example, where a variable gets pulled into the braces and it also causes false positive. Transformation is: const1 * (const2 * var1 - const3 * var2) =>

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #15 from Dmitry Babokin --- The bug is almost 2 years old. I consider it's quite important, as false positives make UBSAN not usable on any large codebases.

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Marc Glisse changed: What|Removed |Added CC||babokin at gmail dot com --- Comment #14

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Richard Biener changed: What|Removed |Added CC||ishiura-compiler at ml dot kwansei

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Richard Biener changed: What|Removed |Added URL||https://gcc.gnu.org/ml/gcc-

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #11 from Marc Glisse --- Does the patch still exist? Did it fail testing?

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Richard Biener changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #7 from Richard Biener rguenth at gcc dot gnu.org --- gcc.dg/tree-ssa/pr23294.c should be still optimized, no? there is not a single case with a possibly overflowing addition in there.

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #9 from Marek Polacek mpolacek at gcc dot gnu.org --- With the conversion to unsigned we're also no longer able to optimize tree-ssa/tailrecursion-6.c.

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #8 from Marek Polacek mpolacek at gcc dot gnu.org --- Right now .optimized looks like this: f6 (int a, int b) { int _2; int _4; int _5; bb 2: _2 = a_1(D) * 3; _4 = _2 - b_3(D); _5 = _4 * 2; return _5; }

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #5 from Marek Polacek mpolacek at gcc dot gnu.org --- I think I'll restrict the computation in unsigned only for TYPE_OVERFLOW_SANITIZED, otherwise we fail to optimize important stuff :/ (e.g. tree-ssa/pr23294.c).

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #6 from Marek Polacek mpolacek at gcc dot gnu.org --- No, that's not a good approach either.

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #4 from Marek Polacek mpolacek at gcc dot gnu.org --- Ok, then I'll try to fix it up there. A testcase: /* PR middle-end/66313 */ /* { dg-do run } */ /* { dg-options -fsanitize=undefined -fsanitize-undefined-trap-on-error } */ int

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Marek Polacek mpolacek at gcc dot gnu.org changed: What|Removed |Added CC||mpolacek at

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 --- Comment #3 from Richard Biener rguenth at gcc dot gnu.org --- I'm actually testing a patch that moves all of this to match.pd (without fixing this, that said)

[Bug middle-end/66313] Unsafe factorization of a*b+a*c

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66313 Richard Biener rguenth at gcc dot gnu.org changed: What|Removed |Added Keywords||wrong-code