https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113455
--- Comment #6 from Joseph S. Myers <jsm28 at gcc dot gnu.org> --- -frounding-math is only relevant for arithmetic that occurs as-if at runtime in the abstract machine. Conversion of constants to their type (or a type with excess range and precision as indicated by DEC_EVAL_METHOD, but (a) that doesn't apply here and (b) none of the excess precision support in GCC is hooked up for decimal floating point, I think) occurs at translation time, not at runtime, so is never affected by -frounding-math or fe_dec_setround (and GCC doesn't implement the FENV_DEC_ROUND pragma to set a constant rounding mode in a particular scope).
