diff options
Diffstat (limited to 'sysdeps/ieee754/flt-32/s_erff.c')
| -rw-r--r-- | sysdeps/ieee754/flt-32/s_erff.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/sysdeps/ieee754/flt-32/s_erff.c b/sysdeps/ieee754/flt-32/s_erff.c index 7c09589648..2be44cc40c 100644 --- a/sysdeps/ieee754/flt-32/s_erff.c +++ b/sysdeps/ieee754/flt-32/s_erff.c @@ -33,7 +33,6 @@ erx = 8.4506291151e-01, /* 0x3f58560b */ * Coefficients for approximation to erf on [0,0.84375] */ efx = 1.2837916613e-01, /* 0x3e0375d4 */ -efx8= 1.0270333290e+00, /* 0x3f8375d4 */ pp0 = 1.2837916613e-01, /* 0x3e0375d4 */ pp1 = -3.2504209876e-01, /* 0xbea66beb */ pp2 = -2.8481749818e-02, /* 0xbce9528f */ @@ -111,8 +110,16 @@ float __erff(float x) if(ix < 0x3f580000) { /* |x|<0.84375 */ if(ix < 0x31800000) { /* |x|<2**-28 */ if (ix < 0x04000000) - /*avoid underflow */ - return (float)0.125*((float)8.0*x+efx8*x); + { + /* Avoid spurious underflow. */ + float ret = 0.0625f * (16.0f * x + (16.0f * efx) * x); + if (fabsf (ret) < FLT_MIN) + { + float force_underflow = ret * ret; + math_force_eval (force_underflow); + } + return ret; + } return x + efx*x; } z = x*x; @@ -162,7 +169,7 @@ float __erfcf(float x) } if(ix < 0x3f580000) { /* |x|<0.84375 */ - if(ix < 0x23800000) /* |x|<2**-56 */ + if(ix < 0x32800000) /* |x|<2**-26 */ return one-x; z = x*x; r = pp0+z*(pp1+z*(pp2+z*(pp3+z*pp4))); |