[Bug fortran/83235] IAND sometimes doesn't take bitwise-and of sign bit with -O2

2017-12-01 Thread paul.k.romano at gmail dot com
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83235 --- Comment #5 from Paul Romano --- Got it; thanks for the clarification, and sorry for the noise! Guess I'll just have to stop relying on this "feature" of previous versions.

[Bug fortran/83235] IAND sometimes doesn't take bitwise-and of sign bit with -O2

2017-12-01 Thread jakub at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83235 --- Comment #4 from Jakub Jelinek --- That is a bad understanding of what undefined behavior means. After you invoke undefined behavior anywhere in your program, anything can happen, there are no constraints on what can happen.

[Bug fortran/83235] IAND sometimes doesn't take bitwise-and of sign bit with -O2

2017-12-01 Thread paul.k.romano at gmail dot com
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83235 --- Comment #3 from Paul Romano --- Thank you both for your quick responses. I understand that the bit model for negative numbers is undefined and that x*x overflows and is thus also undefined. However, the second argument to IAND is well-defined

[Bug fortran/83235] IAND sometimes doesn't take bitwise-and of sign bit with -O2

2017-12-01 Thread jakub at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83235 Jakub Jelinek changed: What|Removed |Added Status|UNCONFIRMED |RESOLVED CC|

[Bug fortran/83235] IAND sometimes doesn't take bitwise-and of sign bit with -O2

2017-11-30 Thread kargl at gcc dot gnu.org
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83235 kargl at gcc dot gnu.org changed: What|Removed |Added CC||kargl at gcc dot gnu.org --- C