diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/e_sqrt.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/sysdeps/ieee754/dbl-64/e_sqrt.c b/sysdeps/ieee754/dbl-64/e_sqrt.c index 15ba98d5e7..f7e8055491 100644 --- a/sysdeps/ieee754/dbl-64/e_sqrt.c +++ b/sysdeps/ieee754/dbl-64/e_sqrt.c @@ -41,7 +41,7 @@ #include "math_private.h" /*********************************************************************/ -/* An ultimate aqrt routine. Given an IEEE double machine number x */ +/* An ultimate sqrt routine. Given an IEEE double machine number x */ /* it computes the correctly rounded (to nearest) value of square */ /* root of x. */ /*********************************************************************/ @@ -52,7 +52,7 @@ double __ieee754_sqrt(double x) { rt1 = 4.99999999495955425917856814202739E-01, rt2 = 3.75017500867345182581453026130850E-01, rt3 = 3.12523626554518656309172508769531E-01; - static const double big = 134217728.0, big1 = 134217729.0; + static const double big = 134217728.0; double y,t,del,res,res1,hy,z,zz,p,hx,tx,ty,s; mynumber a,c={{0,0}}; int4 k; @@ -79,13 +79,10 @@ double __ieee754_sqrt(double x) { } } else { - if (k>0x7ff00000) /* x -> infinity */ - return (big1-big1)/(big-big); - if (k<0x00100000) { /* x -> -infinity */ - if (x==0) return x; - if (k<0) return (big1-big1)/(big-big); - else return tm256.x*__ieee754_sqrt(x*t512.x); - } - else return (a.i[LOW_HALF]==0)?x:(big1-big1)/(big-big); + if ((k & 0x7ff00000) == 0x7ff00000) + return x*x+x; /* sqrt(NaN)=NaN, sqrt(+inf)=+inf, sqrt(-inf)=sNaN */ + if (x==0) return x; /* sqrt(+0)=+0, sqrt(-0)=-0 */ + if (k<0) return (x-x)/(x-x); /* sqrt(-ve)=sNaN */ + return tm256.x*__ieee754_sqrt(x*t512.x); } } |