diff options
Diffstat (limited to 'lib/msun/src/e_lgammaf_r.c')
| -rw-r--r-- | lib/msun/src/e_lgammaf_r.c | 57 |
1 files changed, 25 insertions, 32 deletions
diff --git a/lib/msun/src/e_lgammaf_r.c b/lib/msun/src/e_lgammaf_r.c index e2d90ef..9a7ab39 100644 --- a/lib/msun/src/e_lgammaf_r.c +++ b/lib/msun/src/e_lgammaf_r.c @@ -19,8 +19,10 @@ __FBSDID("$FreeBSD$"); #include "math.h" #include "math_private.h" +static const volatile float vzero = 0; + static const float -two23= 8.3886080000e+06, /* 0x4b000000 */ +zero= 0.0000000000e+00, half= 5.0000000000e-01, /* 0x3f000000 */ one = 1.0000000000e+00, /* 0x3f800000 */ pi = 3.1415927410e+00, /* 0x40490fdb */ @@ -87,39 +89,30 @@ w4 = -5.9518753551e-04, /* 0xba1c065c */ w5 = 8.3633989561e-04, /* 0x3a5b3dd2 */ w6 = -1.6309292987e-03; /* 0xbad5c4e8 */ -static const float zero= 0.0000000000e+00; - - static float sin_pif(float x) +static float +sin_pif(float x) { + volatile float vz; float y,z; - int n,ix; + int n; - GET_FLOAT_WORD(ix,x); - ix &= 0x7fffffff; + y = -x; - if(ix<0x3e800000) return __kernel_sindf(pi*x); - y = -x; /* x is assume negative */ + vz = y+0x1p23F; /* depend on 0 <= y < 0x1p23 */ + z = vz-0x1p23F; /* rintf(y) for the above range */ + if (z == y) + return zero; + + vz = y+0x1p21F; + GET_FLOAT_WORD(n,vz); /* bits for rounded y (units 0.25) */ + z = vz-0x1p21F; /* y rounded to a multiple of 0.25 */ + if (z > y) { + z -= 0.25F; /* adjust to round down */ + n--; + } + n &= 7; /* octant of y mod 2 */ + y = y - z + n * 0.25F; /* y mod 2 */ - /* - * argument reduction, make sure inexact flag not raised if input - * is an integer - */ - z = floorf(y); - if(z!=y) { /* inexact anyway */ - y *= (float)0.5; - y = (float)2.0*(y - floorf(y)); /* y = |x| mod 2.0 */ - n = (int) (y*(float)4.0); - } else { - if(ix>=0x4b800000) { - y = zero; n = 0; /* y must be even */ - } else { - if(ix<0x4b000000) z = y+two23; /* exact */ - GET_FLOAT_WORD(n,z); - n &= 1; - y = n; - n<<= 2; - } - } switch (n) { case 0: y = __kernel_sindf(pi*y); break; case 1: @@ -147,7 +140,7 @@ __ieee754_lgammaf_r(float x, int *signgamp) *signgamp = 1; ix = hx&0x7fffffff; if(ix>=0x7f800000) return x*x; - if(ix==0) return one/zero; + if(ix==0) return one/vzero; if(ix<0x35000000) { /* |x|<2**-21, return -log(|x|) */ if(hx<0) { *signgamp = -1; @@ -156,9 +149,9 @@ __ieee754_lgammaf_r(float x, int *signgamp) } if(hx<0) { if(ix>=0x4b000000) /* |x|>=2**23, must be -integer */ - return one/zero; + return one/vzero; t = sin_pif(x); - if(t==zero) return one/zero; /* -integer */ + if(t==zero) return one/vzero; /* -integer */ nadj = __ieee754_logf(pi/fabsf(t*x)); if(t<zero) *signgamp = -1; x = -x; |
