Well presumably one would want to use target dependent stuff for
detecting overflow where it exists (sticky overflow bits on
power, O flag on PC, trapping add on MIPS etc).
On the whole I think you'd want to benefit from tree-ssa optimizing
overflow checks where possible (including optimizing them away with VRP),
if you hope for a -ftrapv that could be turned on by default for Ada with
performance impact as small as possible. That would suggest back ends
matching overflow-check patterns and converting them into such
instructions.
Yes, fully fully agreed.
Paolo
