On Wed, Jun 25, 2014 at 11:12 AM, Bernd Edlinger <bernd.edlin...@hotmail.de> wrote: > Hi, > > this is part 2 of my patch, which uses the undefined behaviour, and emits a > strict overflow warning. > This fixes gnat.dg/opt37.adb again. > > The diff is relative to part 1: > https://gcc.gnu.org/ml/gcc-patches/2014-06/msg01891.html > > > Boot-strapped and regression-tested on x86_64-linux-gnu. > > OK for trunk?
+ /* For integer types, if A has a smaller type + than T the result depends on the possible + overflow in P + A. + E.g. T=size_t, A=(unsigned)429497295, P>0. + However, if an overflow in P + A would cause + undefined behavior, we can assume that there + is no overflow. */ + || (!POINTER_TYPE_P (TREE_TYPE (p)) + && INTEGRAL_TYPE_P (TREE_TYPE (a)) + && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (a))) it's clearer to simply test INTEGRAL_TYPE_P (TREE_TYPE (p)), that way we know that A is also integral type. For consistency then check TYPE_OVERFLOW_UNDEFINED on p as well. + if (issue_strict_overflow_warning + (WARN_STRICT_OVERFLOW_MISC) + && TYPE_PRECISION (TREE_TYPE (rhs1)) + > TYPE_PRECISION (TREE_TYPE (a)) + && !POINTER_TYPE_P (TREE_TYPE (p))) + warning_at (gimple_location (stmt), likewise here, check for INTEGRAL_TYPE_P (p). Ok with that change. Thanks, Richard. > > Thanks > Bernd. >
