diff options
Diffstat (limited to 'sysdeps/ieee754/flt-32/e_exp2f.c')
| -rw-r--r-- | sysdeps/ieee754/flt-32/e_exp2f.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sysdeps/ieee754/flt-32/e_exp2f.c b/sysdeps/ieee754/flt-32/e_exp2f.c index f3e3a8e..0b75a7e 100644 --- a/sysdeps/ieee754/flt-32/e_exp2f.c +++ b/sysdeps/ieee754/flt-32/e_exp2f.c @@ -89,7 +89,9 @@ __ieee754_exp2f (float x) /* 3. Compute ex2 = 2^(t/255+e+ex). */ ex2_u.f = __exp2f_atable[tval & 255]; tval >>= 8; - unsafe = abs(tval) >= -FLT_MIN_EXP - 1; + /* x2 is an integer multiple of 2^-30; avoid intermediate + underflow from the calculation of x22 * x. */ + unsafe = abs(tval) >= -FLT_MIN_EXP - 32; ex2_u.ieee.exponent += tval >> unsafe; scale_u.f = 1.0; scale_u.ieee.exponent += tval - (tval >> unsafe); |