https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92230
Bug ID: 92230
Summary: Proposal to have builtin underflow detection function
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: arieltorti14 at gmail dot com
Target Milestone: ---
Right now GCC provides `__builtin_sub_overflow` to check for overflows during
subtraction, but there's not way to check for underflow, other than maybe
comparing the operators beforehand.
Maybe it would be a good idea to have `__builtin_sub_underflow` functions which
could be optimized at a greater level by reading the flags instead of doing
integer comparisons.
As a side note, is the behavior of `__builtin_sub_overflow` the intended one ?
