https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111709
--- Comment #23 from Joseph S. Myers <jsm28 at gcc dot gnu.org> --- hppa is an after-rounding architecture and this test is only meant to produce underflow on before-rounding architectures. You should investigate why the code in question is entered at all. I'd have expected /* If the exponent would be in the normal range when rounding to normal precision with unbounded exponent range, the exact result is known and spurious underflows must be avoided on systems detecting tininess after rounding. */ if (TININESS_AFTER_ROUNDING) { w.d = a1 + u.d; if (w.ieee.exponent == 109) return w.d * 0x1p-108; } to have dealt with this case.