See http://gcc.gnu.org/ml/gcc-patches/2007-10/msg01011.html ``When -ftrapv is in effect, libcalls are "necessary" so that the results of an operation can be propagated without making the call to the libgcc functions dead. The attached patch causes a failure in pr30286.c.'' This has to be investigated before libcall notes can be removed from the compiler.
-ftrapv is seriously broken and nobody wants to fix it; so the most appealing solution is to remove support for -ftrapv. See PR19020, especially the libcall part is broken as well.
PR19020 shows that -ftrapv vs. libcalls is broken even without Paolo's patch.
Well, regression is a big word because -ftrapv is broken in general. I guess the RM will lower the priority.
Not a regression. $Summary was true always.
Not a regression, removing milestone.
*** Bug 39771 has been marked as a duplicate of this bug. ***
I'm reopening this report. -ftrapv is still documented, so can be expected to work by users. For the particular problem I have right now, a functional version of this option would be a great thing to have.
*** Bug 40143 has been marked as a duplicate of this bug. ***
Please fix. Per the documentation available `-fsantize=undefined` provides some of the missing functionality but does not allow the program's flow to be altered.