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Diffstat (limited to 'libc/sysdeps/ieee754/dbl-64/s_erf.c')
-rw-r--r--libc/sysdeps/ieee754/dbl-64/s_erf.c523
1 files changed, 258 insertions, 265 deletions
diff --git a/libc/sysdeps/ieee754/dbl-64/s_erf.c b/libc/sysdeps/ieee754/dbl-64/s_erf.c
index e25e28d9d..aab4ed593 100644
--- a/libc/sysdeps/ieee754/dbl-64/s_erf.c
+++ b/libc/sysdeps/ieee754/dbl-64/s_erf.c
@@ -116,181 +116,176 @@ static char rcsid[] = "$NetBSD: s_erf.c,v 1.8 1995/05/10 20:47:05 jtc Exp $";
#include <math_private.h>
static const double
-tiny = 1e-300,
-half= 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */
-one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
-two = 2.00000000000000000000e+00, /* 0x40000000, 0x00000000 */
- /* c = (float)0.84506291151 */
-erx = 8.45062911510467529297e-01, /* 0x3FEB0AC1, 0x60000000 */
+ tiny = 1e-300,
+ half = 5.00000000000000000000e-01, /* 0x3FE00000, 0x00000000 */
+ one = 1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
+ two = 2.00000000000000000000e+00, /* 0x40000000, 0x00000000 */
+/* c = (float)0.84506291151 */
+ erx = 8.45062911510467529297e-01, /* 0x3FEB0AC1, 0x60000000 */
/*
* Coefficients for approximation to erf on [0,0.84375]
*/
-efx = 1.28379167095512586316e-01, /* 0x3FC06EBA, 0x8214DB69 */
-efx8= 1.02703333676410069053e+00, /* 0x3FF06EBA, 0x8214DB69 */
-pp[] = {1.28379167095512558561e-01, /* 0x3FC06EBA, 0x8214DB68 */
- -3.25042107247001499370e-01, /* 0xBFD4CD7D, 0x691CB913 */
- -2.84817495755985104766e-02, /* 0xBF9D2A51, 0xDBD7194F */
- -5.77027029648944159157e-03, /* 0xBF77A291, 0x236668E4 */
- -2.37630166566501626084e-05}, /* 0xBEF8EAD6, 0x120016AC */
-qq[] = {0.0, 3.97917223959155352819e-01, /* 0x3FD97779, 0xCDDADC09 */
- 6.50222499887672944485e-02, /* 0x3FB0A54C, 0x5536CEBA */
- 5.08130628187576562776e-03, /* 0x3F74D022, 0xC4D36B0F */
- 1.32494738004321644526e-04, /* 0x3F215DC9, 0x221C1A10 */
- -3.96022827877536812320e-06}, /* 0xBED09C43, 0x42A26120 */
+ efx = 1.28379167095512586316e-01, /* 0x3FC06EBA, 0x8214DB69 */
+ efx8 = 1.02703333676410069053e+00, /* 0x3FF06EBA, 0x8214DB69 */
+ pp[] = { 1.28379167095512558561e-01, /* 0x3FC06EBA, 0x8214DB68 */
+ -3.25042107247001499370e-01, /* 0xBFD4CD7D, 0x691CB913 */
+ -2.84817495755985104766e-02, /* 0xBF9D2A51, 0xDBD7194F */
+ -5.77027029648944159157e-03, /* 0xBF77A291, 0x236668E4 */
+ -2.37630166566501626084e-05 }, /* 0xBEF8EAD6, 0x120016AC */
+ qq[] = { 0.0, 3.97917223959155352819e-01, /* 0x3FD97779, 0xCDDADC09 */
+ 6.50222499887672944485e-02, /* 0x3FB0A54C, 0x5536CEBA */
+ 5.08130628187576562776e-03, /* 0x3F74D022, 0xC4D36B0F */
+ 1.32494738004321644526e-04, /* 0x3F215DC9, 0x221C1A10 */
+ -3.96022827877536812320e-06 }, /* 0xBED09C43, 0x42A26120 */
/*
* Coefficients for approximation to erf in [0.84375,1.25]
*/
-pa[] = {-2.36211856075265944077e-03, /* 0xBF6359B8, 0xBEF77538 */
- 4.14856118683748331666e-01, /* 0x3FDA8D00, 0xAD92B34D */
- -3.72207876035701323847e-01, /* 0xBFD7D240, 0xFBB8C3F1 */
- 3.18346619901161753674e-01, /* 0x3FD45FCA, 0x805120E4 */
- -1.10894694282396677476e-01, /* 0xBFBC6398, 0x3D3E28EC */
- 3.54783043256182359371e-02, /* 0x3FA22A36, 0x599795EB */
- -2.16637559486879084300e-03}, /* 0xBF61BF38, 0x0A96073F */
-qa[] = {0.0, 1.06420880400844228286e-01, /* 0x3FBB3E66, 0x18EEE323 */
- 5.40397917702171048937e-01, /* 0x3FE14AF0, 0x92EB6F33 */
- 7.18286544141962662868e-02, /* 0x3FB2635C, 0xD99FE9A7 */
- 1.26171219808761642112e-01, /* 0x3FC02660, 0xE763351F */
- 1.36370839120290507362e-02, /* 0x3F8BEDC2, 0x6B51DD1C */
- 1.19844998467991074170e-02}, /* 0x3F888B54, 0x5735151D */
+ pa[] = { -2.36211856075265944077e-03, /* 0xBF6359B8, 0xBEF77538 */
+ 4.14856118683748331666e-01, /* 0x3FDA8D00, 0xAD92B34D */
+ -3.72207876035701323847e-01, /* 0xBFD7D240, 0xFBB8C3F1 */
+ 3.18346619901161753674e-01, /* 0x3FD45FCA, 0x805120E4 */
+ -1.10894694282396677476e-01, /* 0xBFBC6398, 0x3D3E28EC */
+ 3.54783043256182359371e-02, /* 0x3FA22A36, 0x599795EB */
+ -2.16637559486879084300e-03 }, /* 0xBF61BF38, 0x0A96073F */
+ qa[] = { 0.0, 1.06420880400844228286e-01, /* 0x3FBB3E66, 0x18EEE323 */
+ 5.40397917702171048937e-01, /* 0x3FE14AF0, 0x92EB6F33 */
+ 7.18286544141962662868e-02, /* 0x3FB2635C, 0xD99FE9A7 */
+ 1.26171219808761642112e-01, /* 0x3FC02660, 0xE763351F */
+ 1.36370839120290507362e-02, /* 0x3F8BEDC2, 0x6B51DD1C */
+ 1.19844998467991074170e-02 }, /* 0x3F888B54, 0x5735151D */
/*
* Coefficients for approximation to erfc in [1.25,1/0.35]
*/
-ra[] = {-9.86494403484714822705e-03, /* 0xBF843412, 0x600D6435 */
- -6.93858572707181764372e-01, /* 0xBFE63416, 0xE4BA7360 */
- -1.05586262253232909814e+01, /* 0xC0251E04, 0x41B0E726 */
- -6.23753324503260060396e+01, /* 0xC04F300A, 0xE4CBA38D */
- -1.62396669462573470355e+02, /* 0xC0644CB1, 0x84282266 */
- -1.84605092906711035994e+02, /* 0xC067135C, 0xEBCCABB2 */
- -8.12874355063065934246e+01, /* 0xC0545265, 0x57E4D2F2 */
- -9.81432934416914548592e+00}, /* 0xC023A0EF, 0xC69AC25C */
-sa[] = {0.0,1.96512716674392571292e+01, /* 0x4033A6B9, 0xBD707687 */
- 1.37657754143519042600e+02, /* 0x4061350C, 0x526AE721 */
- 4.34565877475229228821e+02, /* 0x407B290D, 0xD58A1A71 */
- 6.45387271733267880336e+02, /* 0x40842B19, 0x21EC2868 */
- 4.29008140027567833386e+02, /* 0x407AD021, 0x57700314 */
- 1.08635005541779435134e+02, /* 0x405B28A3, 0xEE48AE2C */
- 6.57024977031928170135e+00, /* 0x401A47EF, 0x8E484A93 */
- -6.04244152148580987438e-02}, /* 0xBFAEEFF2, 0xEE749A62 */
+ ra[] = { -9.86494403484714822705e-03, /* 0xBF843412, 0x600D6435 */
+ -6.93858572707181764372e-01, /* 0xBFE63416, 0xE4BA7360 */
+ -1.05586262253232909814e+01, /* 0xC0251E04, 0x41B0E726 */
+ -6.23753324503260060396e+01, /* 0xC04F300A, 0xE4CBA38D */
+ -1.62396669462573470355e+02, /* 0xC0644CB1, 0x84282266 */
+ -1.84605092906711035994e+02, /* 0xC067135C, 0xEBCCABB2 */
+ -8.12874355063065934246e+01, /* 0xC0545265, 0x57E4D2F2 */
+ -9.81432934416914548592e+00 }, /* 0xC023A0EF, 0xC69AC25C */
+ sa[] = { 0.0, 1.96512716674392571292e+01, /* 0x4033A6B9, 0xBD707687 */
+ 1.37657754143519042600e+02, /* 0x4061350C, 0x526AE721 */
+ 4.34565877475229228821e+02, /* 0x407B290D, 0xD58A1A71 */
+ 6.45387271733267880336e+02, /* 0x40842B19, 0x21EC2868 */
+ 4.29008140027567833386e+02, /* 0x407AD021, 0x57700314 */
+ 1.08635005541779435134e+02, /* 0x405B28A3, 0xEE48AE2C */
+ 6.57024977031928170135e+00, /* 0x401A47EF, 0x8E484A93 */
+ -6.04244152148580987438e-02 }, /* 0xBFAEEFF2, 0xEE749A62 */
/*
* Coefficients for approximation to erfc in [1/.35,28]
*/
-rb[] = {-9.86494292470009928597e-03, /* 0xBF843412, 0x39E86F4A */
- -7.99283237680523006574e-01, /* 0xBFE993BA, 0x70C285DE */
- -1.77579549177547519889e+01, /* 0xC031C209, 0x555F995A */
- -1.60636384855821916062e+02, /* 0xC064145D, 0x43C5ED98 */
- -6.37566443368389627722e+02, /* 0xC083EC88, 0x1375F228 */
- -1.02509513161107724954e+03, /* 0xC0900461, 0x6A2E5992 */
- -4.83519191608651397019e+02}, /* 0xC07E384E, 0x9BDC383F */
-sb[] = {0.0,3.03380607434824582924e+01, /* 0x403E568B, 0x261D5190 */
- 3.25792512996573918826e+02, /* 0x40745CAE, 0x221B9F0A */
- 1.53672958608443695994e+03, /* 0x409802EB, 0x189D5118 */
- 3.19985821950859553908e+03, /* 0x40A8FFB7, 0x688C246A */
- 2.55305040643316442583e+03, /* 0x40A3F219, 0xCEDF3BE6 */
- 4.74528541206955367215e+02, /* 0x407DA874, 0xE79FE763 */
- -2.24409524465858183362e+01}; /* 0xC03670E2, 0x42712D62 */
+ rb[] = { -9.86494292470009928597e-03, /* 0xBF843412, 0x39E86F4A */
+ -7.99283237680523006574e-01, /* 0xBFE993BA, 0x70C285DE */
+ -1.77579549177547519889e+01, /* 0xC031C209, 0x555F995A */
+ -1.60636384855821916062e+02, /* 0xC064145D, 0x43C5ED98 */
+ -6.37566443368389627722e+02, /* 0xC083EC88, 0x1375F228 */
+ -1.02509513161107724954e+03, /* 0xC0900461, 0x6A2E5992 */
+ -4.83519191608651397019e+02 }, /* 0xC07E384E, 0x9BDC383F */
+ sb[] = { 0.0, 3.03380607434824582924e+01, /* 0x403E568B, 0x261D5190 */
+ 3.25792512996573918826e+02, /* 0x40745CAE, 0x221B9F0A */
+ 1.53672958608443695994e+03, /* 0x409802EB, 0x189D5118 */
+ 3.19985821950859553908e+03, /* 0x40A8FFB7, 0x688C246A */
+ 2.55305040643316442583e+03, /* 0x40A3F219, 0xCEDF3BE6 */
+ 4.74528541206955367215e+02, /* 0x407DA874, 0xE79FE763 */
+ -2.24409524465858183362e+01 }; /* 0xC03670E2, 0x42712D62 */
-double __erf(double x)
+double
+__erf (double x)
{
- int32_t hx,ix,i;
- double R,S,P,Q,s,y,z,r;
- GET_HIGH_WORD(hx,x);
- ix = hx&0x7fffffff;
- if(ix>=0x7ff00000) { /* erf(nan)=nan */
- i = ((u_int32_t)hx>>31)<<1;
- return (double)(1-i)+one/x; /* erf(+-inf)=+-1 */
- }
+ int32_t hx, ix, i;
+ double R, S, P, Q, s, y, z, r;
+ GET_HIGH_WORD (hx, x);
+ ix = hx & 0x7fffffff;
+ if (ix >= 0x7ff00000) /* erf(nan)=nan */
+ {
+ i = ((u_int32_t) hx >> 31) << 1;
+ return (double) (1 - i) + one / x; /* erf(+-inf)=+-1 */
+ }
- if(ix < 0x3feb0000) { /* |x|<0.84375 */
- double r1,r2,s1,s2,s3,z2,z4;
- if(ix < 0x3e300000) { /* |x|<2**-28 */
- if (ix < 0x00800000)
- return 0.125*(8.0*x+efx8*x); /*avoid underflow */
- return x + efx*x;
- }
- z = x*x;
-#ifdef DO_NOT_USE_THIS
- r = pp0+z*(pp1+z*(pp2+z*(pp3+z*pp4)));
- s = one+z*(qq1+z*(qq2+z*(qq3+z*(qq4+z*qq5))));
-#else
- r1 = pp[0]+z*pp[1]; z2=z*z;
- r2 = pp[2]+z*pp[3]; z4=z2*z2;
- s1 = one+z*qq[1];
- s2 = qq[2]+z*qq[3];
- s3 = qq[4]+z*qq[5];
- r = r1 + z2*r2 + z4*pp[4];
- s = s1 + z2*s2 + z4*s3;
-#endif
- y = r/s;
- return x + x*y;
- }
- if(ix < 0x3ff40000) { /* 0.84375 <= |x| < 1.25 */
- double s2,s4,s6,P1,P2,P3,P4,Q1,Q2,Q3,Q4;
- s = fabs(x)-one;
-#ifdef DO_NOT_USE_THIS
- P = pa0+s*(pa1+s*(pa2+s*(pa3+s*(pa4+s*(pa5+s*pa6)))));
- Q = one+s*(qa1+s*(qa2+s*(qa3+s*(qa4+s*(qa5+s*qa6)))));
-#else
- P1 = pa[0]+s*pa[1]; s2=s*s;
- Q1 = one+s*qa[1]; s4=s2*s2;
- P2 = pa[2]+s*pa[3]; s6=s4*s2;
- Q2 = qa[2]+s*qa[3];
- P3 = pa[4]+s*pa[5];
- Q3 = qa[4]+s*qa[5];
- P4 = pa[6];
- Q4 = qa[6];
- P = P1 + s2*P2 + s4*P3 + s6*P4;
- Q = Q1 + s2*Q2 + s4*Q3 + s6*Q4;
-#endif
- if(hx>=0) return erx + P/Q; else return -erx - P/Q;
- }
- if (ix >= 0x40180000) { /* inf>|x|>=6 */
- if(hx>=0) return one-tiny; else return tiny-one;
- }
- x = fabs(x);
- s = one/(x*x);
- if(ix< 0x4006DB6E) { /* |x| < 1/0.35 */
-#ifdef DO_NOT_USE_THIS
- R=ra0+s*(ra1+s*(ra2+s*(ra3+s*(ra4+s*(
- ra5+s*(ra6+s*ra7))))));
- S=one+s*(sa1+s*(sa2+s*(sa3+s*(sa4+s*(
- sa5+s*(sa6+s*(sa7+s*sa8)))))));
-#else
- double R1,R2,R3,R4,S1,S2,S3,S4,s2,s4,s6,s8;
- R1 = ra[0]+s*ra[1];s2 = s*s;
- S1 = one+s*sa[1]; s4 = s2*s2;
- R2 = ra[2]+s*ra[3];s6 = s4*s2;
- S2 = sa[2]+s*sa[3];s8 = s4*s4;
- R3 = ra[4]+s*ra[5];
- S3 = sa[4]+s*sa[5];
- R4 = ra[6]+s*ra[7];
- S4 = sa[6]+s*sa[7];
- R = R1 + s2*R2 + s4*R3 + s6*R4;
- S = S1 + s2*S2 + s4*S3 + s6*S4 + s8*sa[8];
-#endif
- } else { /* |x| >= 1/0.35 */
-#ifdef DO_NOT_USE_THIS
- R=rb0+s*(rb1+s*(rb2+s*(rb3+s*(rb4+s*(
- rb5+s*rb6)))));
- S=one+s*(sb1+s*(sb2+s*(sb3+s*(sb4+s*(
- sb5+s*(sb6+s*sb7))))));
-#else
- double R1,R2,R3,S1,S2,S3,S4,s2,s4,s6;
- R1 = rb[0]+s*rb[1];s2 = s*s;
- S1 = one+s*sb[1]; s4 = s2*s2;
- R2 = rb[2]+s*rb[3];s6 = s4*s2;
- S2 = sb[2]+s*sb[3];
- R3 = rb[4]+s*rb[5];
- S3 = sb[4]+s*sb[5];
- S4 = sb[6]+s*sb[7];
- R = R1 + s2*R2 + s4*R3 + s6*rb[6];
- S = S1 + s2*S2 + s4*S3 + s6*S4;
-#endif
+ if (ix < 0x3feb0000) /* |x|<0.84375 */
+ {
+ double r1, r2, s1, s2, s3, z2, z4;
+ if (ix < 0x3e300000) /* |x|<2**-28 */
+ {
+ if (ix < 0x00800000)
+ return 0.125 * (8.0 * x + efx8 * x); /*avoid underflow */
+ return x + efx * x;
}
- z = x;
- SET_LOW_WORD(z,0);
- r = __ieee754_exp(-z*z-0.5625)*__ieee754_exp((z-x)*(z+x)+R/S);
- if(hx>=0) return one-r/x; else return r/x-one;
+ z = x * x;
+ r1 = pp[0] + z * pp[1]; z2 = z * z;
+ r2 = pp[2] + z * pp[3]; z4 = z2 * z2;
+ s1 = one + z * qq[1];
+ s2 = qq[2] + z * qq[3];
+ s3 = qq[4] + z * qq[5];
+ r = r1 + z2 * r2 + z4 * pp[4];
+ s = s1 + z2 * s2 + z4 * s3;
+ y = r / s;
+ return x + x * y;
+ }
+ if (ix < 0x3ff40000) /* 0.84375 <= |x| < 1.25 */
+ {
+ double s2, s4, s6, P1, P2, P3, P4, Q1, Q2, Q3, Q4;
+ s = fabs (x) - one;
+ P1 = pa[0] + s * pa[1]; s2 = s * s;
+ Q1 = one + s * qa[1]; s4 = s2 * s2;
+ P2 = pa[2] + s * pa[3]; s6 = s4 * s2;
+ Q2 = qa[2] + s * qa[3];
+ P3 = pa[4] + s * pa[5];
+ Q3 = qa[4] + s * qa[5];
+ P4 = pa[6];
+ Q4 = qa[6];
+ P = P1 + s2 * P2 + s4 * P3 + s6 * P4;
+ Q = Q1 + s2 * Q2 + s4 * Q3 + s6 * Q4;
+ if (hx >= 0)
+ return erx + P / Q;
+ else
+ return -erx - P / Q;
+ }
+ if (ix >= 0x40180000) /* inf>|x|>=6 */
+ {
+ if (hx >= 0)
+ return one - tiny;
+ else
+ return tiny - one;
+ }
+ x = fabs (x);
+ s = one / (x * x);
+ if (ix < 0x4006DB6E) /* |x| < 1/0.35 */
+ {
+ double R1, R2, R3, R4, S1, S2, S3, S4, s2, s4, s6, s8;
+ R1 = ra[0] + s * ra[1]; s2 = s * s;
+ S1 = one + s * sa[1]; s4 = s2 * s2;
+ R2 = ra[2] + s * ra[3]; s6 = s4 * s2;
+ S2 = sa[2] + s * sa[3]; s8 = s4 * s4;
+ R3 = ra[4] + s * ra[5];
+ S3 = sa[4] + s * sa[5];
+ R4 = ra[6] + s * ra[7];
+ S4 = sa[6] + s * sa[7];
+ R = R1 + s2 * R2 + s4 * R3 + s6 * R4;
+ S = S1 + s2 * S2 + s4 * S3 + s6 * S4 + s8 * sa[8];
+ }
+ else /* |x| >= 1/0.35 */
+ {
+ double R1, R2, R3, S1, S2, S3, S4, s2, s4, s6;
+ R1 = rb[0] + s * rb[1]; s2 = s * s;
+ S1 = one + s * sb[1]; s4 = s2 * s2;
+ R2 = rb[2] + s * rb[3]; s6 = s4 * s2;
+ S2 = sb[2] + s * sb[3];
+ R3 = rb[4] + s * rb[5];
+ S3 = sb[4] + s * sb[5];
+ S4 = sb[6] + s * sb[7];
+ R = R1 + s2 * R2 + s4 * R3 + s6 * rb[6];
+ S = S1 + s2 * S2 + s4 * S3 + s6 * S4;
+ }
+ z = x;
+ SET_LOW_WORD (z, 0);
+ r = __ieee754_exp (-z * z - 0.5625) *
+ __ieee754_exp ((z - x) * (z + x) + R / S);
+ if (hx >= 0)
+ return one - r / x;
+ else
+ return r / x - one;
}
weak_alias (__erf, erf)
#ifdef NO_LONG_DOUBLE
@@ -298,117 +293,115 @@ strong_alias (__erf, __erfl)
weak_alias (__erf, erfl)
#endif
-double __erfc(double x)
+double
+__erfc (double x)
{
- int32_t hx,ix;
- double R,S,P,Q,s,y,z,r;
- GET_HIGH_WORD(hx,x);
- ix = hx&0x7fffffff;
- if(ix>=0x7ff00000) { /* erfc(nan)=nan */
- /* erfc(+-inf)=0,2 */
- return (double)(((u_int32_t)hx>>31)<<1)+one/x;
- }
+ int32_t hx, ix;
+ double R, S, P, Q, s, y, z, r;
+ GET_HIGH_WORD (hx, x);
+ ix = hx & 0x7fffffff;
+ if (ix >= 0x7ff00000) /* erfc(nan)=nan */
+ { /* erfc(+-inf)=0,2 */
+ return (double) (((u_int32_t) hx >> 31) << 1) + one / x;
+ }
- if(ix < 0x3feb0000) { /* |x|<0.84375 */
- double r1,r2,s1,s2,s3,z2,z4;
- if(ix < 0x3c700000) /* |x|<2**-56 */
- return one-x;
- z = x*x;
-#ifdef DO_NOT_USE_THIS
- r = pp0+z*(pp1+z*(pp2+z*(pp3+z*pp4)));
- s = one+z*(qq1+z*(qq2+z*(qq3+z*(qq4+z*qq5))));
-#else
- r1 = pp[0]+z*pp[1]; z2=z*z;
- r2 = pp[2]+z*pp[3]; z4=z2*z2;
- s1 = one+z*qq[1];
- s2 = qq[2]+z*qq[3];
- s3 = qq[4]+z*qq[5];
- r = r1 + z2*r2 + z4*pp[4];
- s = s1 + z2*s2 + z4*s3;
-#endif
- y = r/s;
- if(hx < 0x3fd00000) { /* x<1/4 */
- return one-(x+x*y);
- } else {
- r = x*y;
- r += (x-half);
- return half - r ;
- }
+ if (ix < 0x3feb0000) /* |x|<0.84375 */
+ {
+ double r1, r2, s1, s2, s3, z2, z4;
+ if (ix < 0x3c700000) /* |x|<2**-56 */
+ return one - x;
+ z = x * x;
+ r1 = pp[0] + z * pp[1]; z2 = z * z;
+ r2 = pp[2] + z * pp[3]; z4 = z2 * z2;
+ s1 = one + z * qq[1];
+ s2 = qq[2] + z * qq[3];
+ s3 = qq[4] + z * qq[5];
+ r = r1 + z2 * r2 + z4 * pp[4];
+ s = s1 + z2 * s2 + z4 * s3;
+ y = r / s;
+ if (hx < 0x3fd00000) /* x<1/4 */
+ {
+ return one - (x + x * y);
}
- if(ix < 0x3ff40000) { /* 0.84375 <= |x| < 1.25 */
- double s2,s4,s6,P1,P2,P3,P4,Q1,Q2,Q3,Q4;
- s = fabs(x)-one;
-#ifdef DO_NOT_USE_THIS
- P = pa0+s*(pa1+s*(pa2+s*(pa3+s*(pa4+s*(pa5+s*pa6)))));
- Q = one+s*(qa1+s*(qa2+s*(qa3+s*(qa4+s*(qa5+s*qa6)))));
-#else
- P1 = pa[0]+s*pa[1]; s2=s*s;
- Q1 = one+s*qa[1]; s4=s2*s2;
- P2 = pa[2]+s*pa[3]; s6=s4*s2;
- Q2 = qa[2]+s*qa[3];
- P3 = pa[4]+s*pa[5];
- Q3 = qa[4]+s*qa[5];
- P4 = pa[6];
- Q4 = qa[6];
- P = P1 + s2*P2 + s4*P3 + s6*P4;
- Q = Q1 + s2*Q2 + s4*Q3 + s6*Q4;
-#endif
- if(hx>=0) {
- z = one-erx; return z - P/Q;
- } else {
- z = erx+P/Q; return one+z;
- }
+ else
+ {
+ r = x * y;
+ r += (x - half);
+ return half - r;
}
- if (ix < 0x403c0000) { /* |x|<28 */
- x = fabs(x);
- s = one/(x*x);
- if(ix< 0x4006DB6D) { /* |x| < 1/.35 ~ 2.857143*/
-#ifdef DO_NOT_USE_THIS
- R=ra0+s*(ra1+s*(ra2+s*(ra3+s*(ra4+s*(
- ra5+s*(ra6+s*ra7))))));
- S=one+s*(sa1+s*(sa2+s*(sa3+s*(sa4+s*(
- sa5+s*(sa6+s*(sa7+s*sa8)))))));
-#else
- double R1,R2,R3,R4,S1,S2,S3,S4,s2,s4,s6,s8;
- R1 = ra[0]+s*ra[1];s2 = s*s;
- S1 = one+s*sa[1]; s4 = s2*s2;
- R2 = ra[2]+s*ra[3];s6 = s4*s2;
- S2 = sa[2]+s*sa[3];s8 = s4*s4;
- R3 = ra[4]+s*ra[5];
- S3 = sa[4]+s*sa[5];
- R4 = ra[6]+s*ra[7];
- S4 = sa[6]+s*sa[7];
- R = R1 + s2*R2 + s4*R3 + s6*R4;
- S = S1 + s2*S2 + s4*S3 + s6*S4 + s8*sa[8];
-#endif
- } else { /* |x| >= 1/.35 ~ 2.857143 */
- double R1,R2,R3,S1,S2,S3,S4,s2,s4,s6;
- if(hx<0&&ix>=0x40180000) return two-tiny;/* x < -6 */
-#ifdef DO_NOT_USE_THIS
- R=rb0+s*(rb1+s*(rb2+s*(rb3+s*(rb4+s*(
- rb5+s*rb6)))));
- S=one+s*(sb1+s*(sb2+s*(sb3+s*(sb4+s*(
- sb5+s*(sb6+s*sb7))))));
-#else
- R1 = rb[0]+s*rb[1];s2 = s*s;
- S1 = one+s*sb[1]; s4 = s2*s2;
- R2 = rb[2]+s*rb[3];s6 = s4*s2;
- S2 = sb[2]+s*sb[3];
- R3 = rb[4]+s*rb[5];
- S3 = sb[4]+s*sb[5];
- S4 = sb[6]+s*sb[7];
- R = R1 + s2*R2 + s4*R3 + s6*rb[6];
- S = S1 + s2*S2 + s4*S3 + s6*S4;
-#endif
- }
- z = x;
- SET_LOW_WORD(z,0);
- r = __ieee754_exp(-z*z-0.5625)*
- __ieee754_exp((z-x)*(z+x)+R/S);
- if(hx>0) return r/x; else return two-r/x;
- } else {
- if(hx>0) return tiny*tiny; else return two-tiny;
+ }
+ if (ix < 0x3ff40000) /* 0.84375 <= |x| < 1.25 */
+ {
+ double s2, s4, s6, P1, P2, P3, P4, Q1, Q2, Q3, Q4;
+ s = fabs (x) - one;
+ P1 = pa[0] + s * pa[1]; s2 = s * s;
+ Q1 = one + s * qa[1]; s4 = s2 * s2;
+ P2 = pa[2] + s * pa[3]; s6 = s4 * s2;
+ Q2 = qa[2] + s * qa[3];
+ P3 = pa[4] + s * pa[5];
+ Q3 = qa[4] + s * qa[5];
+ P4 = pa[6];
+ Q4 = qa[6];
+ P = P1 + s2 * P2 + s4 * P3 + s6 * P4;
+ Q = Q1 + s2 * Q2 + s4 * Q3 + s6 * Q4;
+ if (hx >= 0)
+ {
+ z = one - erx; return z - P / Q;
+ }
+ else
+ {
+ z = erx + P / Q; return one + z;
+ }
+ }
+ if (ix < 0x403c0000) /* |x|<28 */
+ {
+ x = fabs (x);
+ s = one / (x * x);
+ if (ix < 0x4006DB6D) /* |x| < 1/.35 ~ 2.857143*/
+ {
+ double R1, R2, R3, R4, S1, S2, S3, S4, s2, s4, s6, s8;
+ R1 = ra[0] + s * ra[1]; s2 = s * s;
+ S1 = one + s * sa[1]; s4 = s2 * s2;
+ R2 = ra[2] + s * ra[3]; s6 = s4 * s2;
+ S2 = sa[2] + s * sa[3]; s8 = s4 * s4;
+ R3 = ra[4] + s * ra[5];
+ S3 = sa[4] + s * sa[5];
+ R4 = ra[6] + s * ra[7];
+ S4 = sa[6] + s * sa[7];
+ R = R1 + s2 * R2 + s4 * R3 + s6 * R4;
+ S = S1 + s2 * S2 + s4 * S3 + s6 * S4 + s8 * sa[8];
+ }
+ else /* |x| >= 1/.35 ~ 2.857143 */
+ {
+ double R1, R2, R3, S1, S2, S3, S4, s2, s4, s6;
+ if (hx < 0 && ix >= 0x40180000)
+ return two - tiny; /* x < -6 */
+ R1 = rb[0] + s * rb[1]; s2 = s * s;
+ S1 = one + s * sb[1]; s4 = s2 * s2;
+ R2 = rb[2] + s * rb[3]; s6 = s4 * s2;
+ S2 = sb[2] + s * sb[3];
+ R3 = rb[4] + s * rb[5];
+ S3 = sb[4] + s * sb[5];
+ S4 = sb[6] + s * sb[7];
+ R = R1 + s2 * R2 + s4 * R3 + s6 * rb[6];
+ S = S1 + s2 * S2 + s4 * S3 + s6 * S4;
}
+ z = x;
+ SET_LOW_WORD (z, 0);
+ r = __ieee754_exp (-z * z - 0.5625) *
+ __ieee754_exp ((z - x) * (z + x) + R / S);
+ if (hx > 0)
+ return r / x;
+ else
+ return two - r / x;
+ }
+ else
+ {
+ if (hx > 0)
+ return tiny * tiny;
+ else
+ return two - tiny;
+ }
}
weak_alias (__erfc, erfc)
#ifdef NO_LONG_DOUBLE
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-03 20:26:43 +0000