subject:"\[Bug tree\-optimization\/91555\] \[9.2 regression\] Optimizer bug"

[Bug tree-optimization/91555] [9.2 regression] Optimizer bug

2019-08-26 Thread skunk at iskunk dot org

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91555 --- Comment #10 from Daniel Richard G. --- Okay. I'll accept that the code is dodgy. Thanks for looking into this. I'll keep in mind -fsanitize=undefined as a way of tracking down these issues in the future.

[Bug tree-optimization/91555] [9.2 regression] Optimizer bug

2019-08-26 Thread pinskia at gcc dot gnu.org

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91555 Andrew Pinski changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED Resolution|---

[Bug tree-optimization/91555] [9.2 regression] Optimizer bug

2019-08-26 Thread skunk at iskunk dot org

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91555 --- Comment #8 from Daniel Richard G. --- The most I could tell via strategic printf() calls is that everything appears to run correctly up until the binary search. I don't think any (unchecked) overflow is at issue, but it seems I don't have a w

[Bug tree-optimization/91555] [9.2 regression] Optimizer bug

2019-08-26 Thread pinskia at gcc dot gnu.org

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91555 --- Comment #7 from Andrew Pinski --- (In reply to Daniel Richard G. from comment #6) > Unfortunately, this GCC build does not have libsanitizer, as it is on an > older (Linux) system without the necessary system headers. > > $ gcc -O2 -fsan

[Bug tree-optimization/91555] [9.2 regression] Optimizer bug

2019-08-26 Thread skunk at iskunk dot org

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91555 --- Comment #6 from Daniel Richard G. --- Unfortunately, this GCC build does not have libsanitizer, as it is on an older (Linux) system without the necessary system headers. $ gcc -O2 -fsanitize=undefined gcc9-opt-bug.c -o bug /usr/bin/l

[Bug tree-optimization/91555] [9.2 regression] Optimizer bug

2019-08-26 Thread pinskia at gcc dot gnu.org

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91555 --- Comment #5 from Andrew Pinski --- Also does -fsanitize=undefined print anything at runtime? If so there is no bug with GCC.

[Bug tree-optimization/91555] [9.2 regression] Optimizer bug

2019-08-26 Thread skunk at iskunk dot org

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91555 --- Comment #4 from Daniel Richard G. --- Yes, that is the case: $ gcc -O2 gcc9-opt-bug.c -o bug $ ./bug WRONG 13 result: t = 18446744073709551615 (wrong) $ gcc -O2 -fwrapv gcc9-opt-bug.c -o bug $ ./bug result: t = 1