diff options
Diffstat (limited to 'libquadmath/math/fmaq.c')
| -rw-r--r-- | libquadmath/math/fmaq.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/libquadmath/math/fmaq.c b/libquadmath/math/fmaq.c index 23e3188669e..5616c1a2781 100644 --- a/libquadmath/math/fmaq.c +++ b/libquadmath/math/fmaq.c @@ -228,6 +228,17 @@ fmaq (__float128 x, __float128 y, __float128 z) for proper rounding. */ if (v.ieee.exponent == 226) { + /* 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.value = a1 + u.value; + if (w.ieee.exponent == 227) + return w.value * 0x1p-226L; + } /* v.ieee.mant_low & 2 is LSB bit of the result before rounding, v.ieee.mant_low & 1 is the round bit and j is our sticky bit. */ |