本文整理汇总了C++中GET_FLOAT_WORD函数的典型用法代码示例。如果您正苦于以下问题：C++ GET_FLOAT_WORD函数的具体用法？C++ GET_FLOAT_WORD怎么用？C++ GET_FLOAT_WORD使用的例子？那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。
在下文中一共展示了GET_FLOAT_WORD函数的20个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于我们的系统推荐出更棒的C++代码示例。
示例1: acosf
float
acosf(float x)
{
float z,p,q,r,w,s,c,df;
int32_t hx,ix;
GET_FLOAT_WORD(hx,x);
ix = hx&0x7fffffff;
if(ix==0x3f800000) { /* |x|==1 */
if(hx>0) return 0.0; /* acos(1) = 0 */
else return pi+(float)2.0*pio2_lo; /* acos(-1)= pi */
} else if(ix>0x3f800000) { /* |x| >= 1 */
return (x-x)/(x-x); /* acos(|x|>1) is NaN */
}
if(ix<0x3f000000) { /* |x| < 0.5 */
if(ix<=0x23000000) return pio2_hi+pio2_lo;/*if|x|<2**-57*/
z = x*x;
p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
r = p/q;
return pio2_hi - (x - (pio2_lo-x*r));
} else if (hx<0) { /* x < -0.5 */
z = (one+x)*(float)0.5;
p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
s = sqrtf(z);
r = p/q;
w = r*s-pio2_lo;
return pi - (float)2.0*(s+w);
} else { /* x > 0.5 */
int32_t idf;
z = (one-x)*(float)0.5;
s = sqrtf(z);
df = s;
GET_FLOAT_WORD(idf,df);
SET_FLOAT_WORD(df,idf&0xfffff000);
c = (z-df*df)/(s+df);
p = z*(pS0+z*(pS1+z*(pS2+z*(pS3+z*(pS4+z*pS5)))));
q = one+z*(qS1+z*(qS2+z*(qS3+z*qS4)));
r = p/q;
w = r*s+c;
return (float)2.0*(df+w);
}
}
开发者ID:mikekmv，项目名称:aeriebsd-src，代码行数:43，代码来源:e_acosf.c
示例2: frexpf
float
frexpf(float x, int *eptr)
{
int32_t hx,ix;
GET_FLOAT_WORD(hx,x);
ix = 0x7fffffff&hx;
*eptr = 0;
if(ix>=0x7f800000||(ix==0)) return x; /* 0,inf,nan */
if (ix<0x00800000) { /* subnormal */
x *= two25;
GET_FLOAT_WORD(hx,x);
ix = hx&0x7fffffff;
*eptr = -25;
}
*eptr += (ix>>23)-126;
hx = (hx&0x807fffff)|0x3f000000;
*(int*)(void*)&x = hx;
return x;
}
开发者ID:jessicah，项目名称:snowflake-old，代码行数:19，代码来源:s_frexpf.c
示例3: __erff
float __erff(float x)
{
int32_t hx,ix,i;
float R,S,P,Q,s,y,z,r;
GET_FLOAT_WORD(hx,x);
ix = hx&0x7fffffff;
if(ix>=0x7f800000) { /* erf(nan)=nan */
i = ((u_int32_t)hx>>31)<<1;
return (float)(1-i)+one/x; /* erf(+-inf)=+-1 */
}
开发者ID:JamesLinus，项目名称:glibc-mips，代码行数:10，代码来源:s_erff.c
示例4: __ieee754_y0f
float
__ieee754_y0f(float x)
{
float z, s,c,ss,cc,u,v;
int32_t hx,ix;
GET_FLOAT_WORD(hx,x);
ix = 0x7fffffff&hx;
/* Y0(NaN) is NaN, y0(-inf) is Nan, y0(inf) is 0 */
if(ix>=0x7f800000) return one/(x+x*x);
if(ix==0) return -one/zero;
if(hx<0) return zero/zero;
if(ix >= 0x40000000) { /* |x| >= 2.0 */
/* y0(x) = sqrt(2/(pi*x))*(p0(x)*sin(x0)+q0(x)*cos(x0))
* where x0 = x-pi/4
* Better formula:
* cos(x0) = cos(x)cos(pi/4)+sin(x)sin(pi/4)
* = 1/sqrt(2) * (sin(x) + cos(x))
* sin(x0) = sin(x)cos(3pi/4)-cos(x)sin(3pi/4)
* = 1/sqrt(2) * (sin(x) - cos(x))
* To avoid cancellation, use
* sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x))
* to compute the worse one.
*/
s = sinf(x);
c = cosf(x);
ss = s-c;
cc = s+c;
/*
* j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x)
* y0(x) = 1/sqrt(pi) * (P(0,x)*ss + Q(0,x)*cc) / sqrt(x)
*/
if(ix<0x7f000000) { /* make sure x+x not overflow */
z = -cosf(x+x);
if ((s*c)<zero) cc = z/ss;
else ss = z/cc;
}
#ifdef DEAD_CODE
if(ix>0x80000000) z = (invsqrtpi*ss)/sqrtf(x);
else
#endif
{
u = pzerof(x); v = qzerof(x);
z = invsqrtpi*(u*ss+v*cc)/sqrtf(x);
}
return z;
}
if(ix<=0x32000000) { /* x < 2**-27 */
return(u00 + tpi*__ieee754_logf(x));
}
z = x*x;
u = u00+z*(u01+z*(u02+z*(u03+z*(u04+z*(u05+z*u06)))));
v = one+z*(v01+z*(v02+z*(v03+z*v04)));
return(u/v + tpi*(__ieee754_j0f(x)*__ieee754_logf(x)));
}
开发者ID:HuaiYuSched，项目名称:pok，代码行数:55，代码来源:e_j0f.c
示例5: cosf
float cosf(float x) {
double y;
uint32_t ix;
unsigned n, sign;
GET_FLOAT_WORD(ix, x);
sign = ix >> 31;
ix &= 0x7fffffff;
if (ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
if (ix < 0x39800000) { /* |x| < 2**-12 */
/* raise inexact if x != 0 */
FORCE_EVAL(x + 0x1p120f);
return 1.0f;
}
return __cosdf(x);
}
if (ix <= 0x407b53d1) { /* |x| ~<= 5*pi/4 */
if (ix > 0x4016cbe3) /* |x| ~> 3*pi/4 */
return -__cosdf(sign ? x + c2pio2 : x - c2pio2);
else {
if (sign)
return __sindf(x + c1pio2);
else
return __sindf(c1pio2 - x);
}
}
if (ix <= 0x40e231d5) { /* |x| ~<= 9*pi/4 */
if (ix > 0x40afeddf) /* |x| ~> 7*pi/4 */
return __cosdf(sign ? x + c4pio2 : x - c4pio2);
else {
if (sign)
return __sindf(-x - c3pio2);
else
return __sindf(x - c3pio2);
}
}
/* cos(Inf or NaN) is NaN */
if (ix >= 0x7f800000)
return x - x;
/* general argument reduction needed */
n = __rem_pio2f(x, &y);
switch (n & 3) {
case 0:
return __cosdf(y);
case 1:
return __sindf(-y);
case 2:
return -__cosdf(y);
default:
return __sindf(y);
}
}
开发者ID:freiling，项目名称:mojo，代码行数:55，代码来源:cosf.c
示例6: remainderf
float remainderf(float x, float p)
{
int32_t hx,hp;
uint32_t sx;
float p_half;
GET_FLOAT_WORD(hx, x);
GET_FLOAT_WORD(hp, p);
sx = hx & 0x80000000;
hp &= 0x7fffffff;
hx &= 0x7fffffff;
/* purge off exception values */
if (hp == 0 || hx >= 0x7f800000 || hp > 0x7f800000) /* p = 0, x not finite, p is NaN */
return (x*p)/(x*p);
if (hp <= 0x7effffff)
x = fmodf(x, p + p); /* now x < 2p */
if (hx - hp == 0)
return 0.0f*x;
x = fabsf(x);
p = fabsf(p);
if (hp < 0x01000000) {
if (x + x > p) {
x -= p;
if (x + x >= p)
x -= p;
}
} else {
p_half = 0.5f*p;
if (x > p_half) {
x -= p;
if (x >= p_half)
x -= p;
}
}
GET_FLOAT_WORD(hx, x);
if ((hx & 0x7fffffff) == 0)
hx = 0;
SET_FLOAT_WORD(x, hx ^ sx);
return x;
}
开发者ID:EtchedPixels，项目名称:FUZIX，代码行数:42，代码来源:remainderf.c
示例7: __fpclassifyf
/*
* On the SPU, single precision floating point returns only FP_NORMAL and
* FP_ZERO, since FP_NAN, FP_INFINITE, and FP_SUBNORMAL are not
* supported, base on the common f_fpclassify.c.
*/
int
__fpclassifyf (float x)
{
__uint32_t w;
GET_FLOAT_WORD(w,x);
if (w == 0x00000000 || w == 0x80000000)
return FP_ZERO;
return FP_NORMAL;
}
开发者ID:32bitmicro，项目名称:newlib-nano-1.0，代码行数:16，代码来源:sf_fpclassify.c
示例8: atanf
float atanf(float x)
{
float_t w,s1,s2,z;
uint32_t ix,sign;
int id;
GET_FLOAT_WORD(ix, x);
sign = ix>>31;
ix &= 0x7fffffff;
if (ix >= 0x4c800000) { /* if |x| >= 2**26 */
if (isnan(x))
return x;
z = atanhi[3] + 0x1p-120f;
return sign ? -z : z;
}
if (ix < 0x3ee00000) { /* |x| < 0.4375 */
if (ix < 0x39800000) { /* |x| < 2**-12 */
if (ix < 0x00800000)
/* raise underflow for subnormal x */
FORCE_EVAL(x*x);
return x;
}
id = -1;
} else {
x = fabsf(x);
if (ix < 0x3f980000) { /* |x| < 1.1875 */
if (ix < 0x3f300000) { /* 7/16 <= |x| < 11/16 */
id = 0;
x = (2.0f*x - 1.0f)/(2.0f + x);
} else { /* 11/16 <= |x| < 19/16 */
id = 1;
x = (x - 1.0f)/(x + 1.0f);
}
} else {
if (ix < 0x401c0000) { /* |x| < 2.4375 */
id = 2;
x = (x - 1.5f)/(1.0f + 1.5f*x);
} else { /* 2.4375 <= |x| < 2**26 */
id = 3;
x = -1.0f/x;
}
}
}
/* end of argument reduction */
z = x*x;
w = z*z;
/* break sum from i=0 to 10 aT[i]z**(i+1) into odd and even poly */
s1 = z*(aT[0]+w*(aT[2]+w*aT[4]));
s2 = w*(aT[1]+w*aT[3]);
if (id < 0)
return x - x*(s1+s2);
z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x);
return sign ? -z : z;
}
开发者ID:xboot，项目名称:xboot，代码行数:54，代码来源:atanf.c
示例9: isposf
int isposf(float x)
{
__int32_t wx;
GET_FLOAT_WORD(wx, x);
if (wx & 0x80000000)
return (0);
else
return (1);
}
开发者ID:pafcndg，项目名称:ndgIqSoftwareKit，代码行数:11，代码来源:sf_ispos.c
示例10: nextafterf
float nextafterf(float x, float y) {
int32_t hx, hy, ix, iy;
GET_FLOAT_WORD(hx, x);
GET_FLOAT_WORD(hy, y);
ix = hx & 0x7fffffff; /* |x| */
iy = hy & 0x7fffffff; /* |y| */
/* x is nan or y is nan? */
if ((ix > 0x7f800000) || (iy > 0x7f800000))
return x + y;
if (x == y)
return y;
if (ix == 0) { /* x == 0? */
SET_FLOAT_WORD(x, (hy & 0x80000000) | 1);
return x;
}
if (hx >= 0) { /* x > 0 */
if (hx > hy) { /* x > y: x -= ulp */
hx -= 1;
} else { /* x < y: x += ulp */
hx += 1;
}
} else { /* x < 0 */
if (hy >= 0 || hx > hy) { /* x < y: x -= ulp */
hx -= 1;
} else { /* x > y: x += ulp */
hx += 1;
}
}
hy = hx & 0x7f800000;
if (hy >= 0x7f800000) {
x = x + x; /* overflow */
return x; /* overflow */
}
SET_FLOAT_WORD(x, hx);
return x;
}
开发者ID:joewan，项目名称:mitsuba-renderer，代码行数:41，代码来源:platform_win32.cpp
示例11: __ieee754_remainderf
float
__ieee754_remainderf(float x, float p)
{
int32_t hx,hp;
u_int32_t sx;
float p_half;
GET_FLOAT_WORD(hx,x);
GET_FLOAT_WORD(hp,p);
sx = hx&0x80000000;
hp &= 0x7fffffff;
hx &= 0x7fffffff;
/* purge off exception values */
if((hp==0)|| /* p = 0 */
(hx>=0x7f800000)|| /* x not finite */
((hp>0x7f800000))) /* p is NaN */
return nan_mix_op(x, p, *)/nan_mix_op(x, p, *);
if (hp<=0x7effffff) x = __ieee754_fmodf(x,p+p); /* now x < 2p */
if ((hx-hp)==0) return zero*x;
x = fabsf(x);
p = fabsf(p);
if (hp<0x01000000) {
if(x+x>p) {
x-=p;
if(x+x>=p) x -= p;
}
} else {
p_half = (float)0.5*p;
if(x>p_half) {
x-=p;
if(x>=p_half) x -= p;
}
}
GET_FLOAT_WORD(hx,x);
if ((hx&0x7fffffff)==0) hx = 0;
SET_FLOAT_WORD(x,hx^sx);
return x;
}
开发者ID:android，项目名称:platform_bionic，代码行数:41，代码来源:e_remainderf.c
示例12: atanf
float atanf(float x)
{
float w,s1,s2,z;
int32_t ix,hx,id;
GET_FLOAT_WORD(hx, x);
ix = hx & 0x7fffffff;
if (ix >= 0x4c800000) { /* if |x| >= 2**26 */
if (ix > 0x7f800000) /* NaN */
return x+x;
if (hx > 0)
return atanhi[3] + *(volatile float *)&atanlo[3];
else
return -atanhi[3] - *(volatile float *)&atanlo[3];
}
if (ix < 0x3ee00000) { /* |x| < 0.4375 */
if (ix < 0x39800000) { /* |x| < 2**-12 */
/* raise inexact */
if(huge+x>1.0f)
return x;
}
id = -1;
} else {
x = fabsf(x);
if (ix < 0x3f980000) { /* |x| < 1.1875 */
if (ix < 0x3f300000) { /* 7/16 <= |x| < 11/16 */
id = 0;
x = (2.0f*x - 1.0f)/(2.0f + x);
} else { /* 11/16 <= |x| < 19/16 */
id = 1;
x = (x - 1.0f)/(x + 1.0f);
}
} else {
if (ix < 0x401c0000) { /* |x| < 2.4375 */
id = 2;
x = (x - 1.5f)/(1.0f + 1.5f*x);
} else { /* 2.4375 <= |x| < 2**26 */
id = 3;
x = -1.0f/x;
}
}
}
/* end of argument reduction */
z = x*x;
w = z*z;
/* break sum from i=0 to 10 aT[i]z**(i+1) into odd and even poly */
s1 = z*(aT[0]+w*(aT[2]+w*aT[4]));
s2 = w*(aT[1]+w*aT[3]);
if (id < 0)
return x - x*(s1+s2);
z = atanhi[id] - ((x*(s1+s2) - atanlo[id]) - x);
return hx < 0 ? -z : z;
}
开发者ID:EtchedPixels，项目名称:FUZIX，代码行数:53，代码来源:atanf.c
示例13: cosf
float
cosf(float x)
{
float y[2];
int32_t n, hx, ix;
GET_FLOAT_WORD(hx,x);
ix = hx & 0x7fffffff;
if(ix <= 0x3f490fda) { /* |x| ~<= pi/4 */
if(ix<0x39800000) /* |x| < 2**-12 */
if(((int)x)==0) return 1.0; /* 1 with inexact if x != 0 */
return __kernel_cosdf(x);
}
if(ix<=0x407b53d1) { /* |x| ~<= 5*pi/4 */
if(ix>0x4016cbe3) /* |x| ~> 3*pi/4 */
return -__kernel_cosdf(x + (hx > 0 ? -c2pio2 : c2pio2));
else {
if(hx>0)
return __kernel_sindf(c1pio2 - x);
else
return __kernel_sindf(x + c1pio2);
}
}
if(ix<=0x40e231d5) { /* |x| ~<= 9*pi/4 */
if(ix>0x40afeddf) /* |x| ~> 7*pi/4 */
return __kernel_cosdf(x + (hx > 0 ? -c4pio2 : c4pio2));
else {
if(hx>0)
return __kernel_sindf(x - c3pio2);
else
return __kernel_sindf(-c3pio2 - x);
}
}
/* cos(Inf or NaN) is NaN */
else if (ix>=0x7f800000) return x-x;
/* general argument reduction needed */
else {
n = __ieee754_rem_pio2f(x,y);
switch(n&3) {
case 0:
return __kernel_cosdf((double)y[0]+y[1]);
case 1:
return __kernel_sindf(-(double)y[0]-y[1]);
case 2:
return -__kernel_cosdf((double)y[0]+y[1]);
default:
return __kernel_sindf((double)y[0]+y[1]);
}
}
}
开发者ID:C40，项目名称:metasploit-framework，代码行数:53，代码来源:s_cosf.c
示例14: j0f
float j0f(float x)
{
float z, s,c,ss,cc,r,u,v;
int32_t hx,ix;
GET_FLOAT_WORD(hx, x);
ix = hx & 0x7fffffff;
if (ix >= 0x7f800000)
return 1.0f/(x*x);
x = fabsf(x);
if (ix >= 0x40000000) { /* |x| >= 2.0 */
s = sinf(x);
c = cosf(x);
ss = s-c;
cc = s+c;
if (ix < 0x7f000000) { /* make sure x+x does not overflow */
z = -cosf(x+x);
if (s*c < 0.0f)
cc = z/ss;
else
ss = z/cc;
}
/*
* j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x)
* y0(x) = 1/sqrt(pi) * (P(0,x)*ss + Q(0,x)*cc) / sqrt(x)
*/
if (ix > 0x80000000)
z = (invsqrtpi*cc)/sqrtf(x);
else {
u = pzerof(x);
v = qzerof(x);
z = invsqrtpi*(u*cc-v*ss)/sqrtf(x);
}
return z;
}
if (ix < 0x39000000) { /* |x| < 2**-13 */
/* raise inexact if x != 0 */
if (huge+x > 1.0f) {
if (ix < 0x32000000) /* |x| < 2**-27 */
return 1.0f;
return 1.0f - 0.25f*x*x;
}
}
z = x*x;
r = z*(R02+z*(R03+z*(R04+z*R05)));
s = 1.0f+z*(S01+z*(S02+z*(S03+z*S04)));
if(ix < 0x3F800000) { /* |x| < 1.00 */
return 1.0f + z*(-0.25f + (r/s));
} else {
u = 0.5f*x;
return (1.0f+u)*(1.0f-u) + z*(r/s);
}
}
开发者ID:GregorR，项目名称:musl，代码行数:53，代码来源:j0f.c
示例15: logbf
float
logbf(float x)
{
int32_t ix;
GET_FLOAT_WORD(ix,x);
ix &= 0x7fffffff; /* high |x| */
if(ix==0) return (float)-1.0/fabsf(x);
if(ix>=0x7f800000) return x*x;
if((ix>>=23)==0) /* IEEE 754 logb */
return -126.0;
else
return (float) (ix-127);
开发者ID:chneukirchen，项目名称:musl-chris2，代码行数:12，代码来源:s_logbf.c
示例16: y1f
float y1f(float x)
{
float z,s,c,ss,cc,u,v;
int32_t hx,ix;
GET_FLOAT_WORD(hx, x);
ix = 0x7fffffff & hx;
/* if Y1(NaN) is NaN, Y1(-inf) is NaN, Y1(inf) is 0 */
if (ix >= 0x7f800000)
return 1.0f/(x+x*x);
if (ix == 0)
return -1.0f/0.0f;
if (hx < 0)
return 0.0f/0.0f;
if (ix >= 0x40000000) { /* |x| >= 2.0 */
s = sinf(x);
c = cosf(x);
ss = -s-c;
cc = s-c;
if (ix < 0x7f000000) { /* make sure x+x not overflow */
z = cosf(x+x);
if (s*c > 0.0f)
cc = z/ss;
else
ss = z/cc;
}
/* y1(x) = sqrt(2/(pi*x))*(p1(x)*sin(x0)+q1(x)*cos(x0))
* where x0 = x-3pi/4
* Better formula:
* cos(x0) = cos(x)cos(3pi/4)+sin(x)sin(3pi/4)
* = 1/sqrt(2) * (sin(x) - cos(x))
* sin(x0) = sin(x)cos(3pi/4)-cos(x)sin(3pi/4)
* = -1/sqrt(2) * (cos(x) + sin(x))
* To avoid cancellation, use
* sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x))
* to compute the worse one.
*/
if (ix > 0x48000000)
z = (invsqrtpi*ss)/sqrtf(x);
else {
u = ponef(x);
v = qonef(x);
z = invsqrtpi*(u*ss+v*cc)/sqrtf(x);
}
return z;
}
if (ix <= 0x24800000) /* x < 2**-54 */
return -tpi/x;
z = x*x;
u = U0[0]+z*(U0[1]+z*(U0[2]+z*(U0[3]+z*U0[4])));
v = 1.0f+z*(V0[0]+z*(V0[1]+z*(V0[2]+z*(V0[3]+z*V0[4]))));
return x*(u/v) + tpi*(j1f(x)*logf(x)-1.0f/x);
}
开发者ID:KGG814，项目名称:AOS，代码行数:53，代码来源:j1f.c
示例17: ynf
float ynf(int n, float x) {
uint32_t ix, ib;
int nm1, sign, i;
float a, b, temp;
GET_FLOAT_WORD(ix, x);
sign = ix >> 31;
ix &= 0x7fffffff;
if (ix > 0x7f800000) /* nan */
return x;
if (sign && ix != 0) /* x < 0 */
return 0 / 0.0f;
if (ix == 0x7f800000)
return 0.0f;
if (n == 0)
return y0f(x);
if (n < 0) {
nm1 = -(n + 1);
sign = n & 1;
} else {
nm1 = n - 1;
sign = 0;
}
if (nm1 == 0)
return sign ? -y1f(x) : y1f(x);
a = y0f(x);
b = y1f(x);
/* quit if b is -inf */
GET_FLOAT_WORD(ib, b);
for (i = 0; i < nm1 && ib != 0xff800000;) {
i++;
temp = b;
b = (2.0f * i / x) * b - a;
GET_FLOAT_WORD(ib, b);
a = temp;
}
return sign ? -b : b;
}
开发者ID:saltstar，项目名称:smartnix，代码行数:40，代码来源:jnf.c
示例18: __ieee754_asinf
float __ieee754_asinf(float x)
{
float t,w,p,q,c,r,s;
int32_t hx,ix;
GET_FLOAT_WORD(hx,x);
ix = hx&0x7fffffff;
if(ix==0x3f800000) {
/* asin(1)=+-pi/2 with inexact */
return x*pio2_hi+x*pio2_lo;
} else if(ix> 0x3f800000) { /* |x|>= 1 */
return (x-x)/(x-x); /* asin(|x|>1) is NaN */
} else if (ix<0x3f000000) { /* |x|<0.5 */
if(ix<0x32000000) { /* if |x| < 2**-27 */
if(huge+x>one) return x;/* return x with inexact if x!=0*/
} else {
t = x*x;
w = t * (p0 + t * (p1 + t * (p2 + t * (p3 + t * p4))));
return x+x*w;
}
}
/* 1> |x|>= 0.5 */
w = one-fabsf(x);
t = w*0.5f;
p = t * (p0 + t * (p1 + t * (p2 + t * (p3 + t * p4))));
s = __ieee754_sqrtf(t);
if(ix>=0x3F79999A) { /* if |x| > 0.975 */
t = pio2_hi-(2.0f*(s+s*p)-pio2_lo);
} else {
int32_t iw;
w = s;
GET_FLOAT_WORD(iw,w);
SET_FLOAT_WORD(w,iw&0xfffff000);
c = (t-w*w)/(s+w);
r = p;
p = 2.0f*s*r-(pio2_lo-2.0f*c);
q = pio4_hi-2.0f*w;
t = pio4_hi-(p-q);
}
if(hx>0) return t; else return -t;
}
开发者ID:Dinesh-Ramakrishnan，项目名称:glibc，代码行数:40，代码来源:e_asinf.c
示例19: __ieee754_log10f
float
__ieee754_log10f(float x)
{
float f,hfsq,hi,lo,r,y;
int32_t i,k,hx;
GET_FLOAT_WORD(hx,x);
k=0;
if (hx < 0x00800000) { /* x < 2**-126 */
if ((hx&0x7fffffff)==0)
return -two25/vzero; /* log(+-0)=-inf */
if (hx<0) return (x-x)/zero; /* log(-#) = NaN */
k -= 25; x *= two25; /* subnormal number, scale up x */
GET_FLOAT_WORD(hx,x);
}
if (hx >= 0x7f800000) return x+x;
if (hx == 0x3f800000)
return zero; /* log(1) = +0 */
k += (hx>>23)-127;
hx &= 0x007fffff;
i = (hx+(0x4afb0d))&0x800000;
SET_FLOAT_WORD(x,hx|(i^0x3f800000)); /* normalize x or x/2 */
k += (i>>23);
y = (float)k;
f = x - (float)1.0;
hfsq = (float)0.5*f*f;
r = k_log1pf(f);
/* See e_log2f.c and e_log2.c for details. */
if (sizeof(float_t) > sizeof(float))
return (r - hfsq + f) * ((float_t)ivln10lo + ivln10hi) +
y * ((float_t)log10_2lo + log10_2hi);
hi = f - hfsq;
GET_FLOAT_WORD(hx,hi);
SET_FLOAT_WORD(hi,hx&0xfffff000);
lo = (f - hi) - hfsq + r;
return y*log10_2lo + (lo+hi)*ivln10lo + lo*ivln10hi + hi*ivln10hi +
y*log10_2hi;
}
开发者ID:MattDooner，项目名称:freebsd-west，代码行数:40，代码来源:e_log10f.c
示例20: __ieee754_y1f
float
__ieee754_y1f(float x)
{
float z, s,c,ss,cc,u,v;
int32_t hx,ix;
GET_FLOAT_WORD(hx,x);
ix = 0x7fffffff&hx;
/* if Y1(NaN) is NaN, Y1(-inf) is NaN, Y1(inf) is 0 */
if(__builtin_expect(ix>=0x7f800000, 0)) return one/(x+x*x);
if(__builtin_expect(ix==0, 0))
return -HUGE_VALF+x; /* -inf and overflow exception. */
if(__builtin_expect(hx<0, 0)) return zero/(zero*x);
if(ix >= 0x40000000) { /* |x| >= 2.0 */
SET_RESTORE_ROUNDF (FE_TONEAREST);
__sincosf (x, &s, &c);
ss = -s-c;
cc = s-c;
if(ix<0x7f000000) { /* make sure x+x not overflow */
z = __cosf(x+x);
if ((s*c)>zero) cc = z/ss;
else ss = z/cc;
}
/* y1(x) = sqrt(2/(pi*x))*(p1(x)*sin(x0)+q1(x)*cos(x0))
* where x0 = x-3pi/4
* Better formula:
* cos(x0) = cos(x)cos(3pi/4)+sin(x)sin(3pi/4)
* = 1/sqrt(2) * (sin(x) - cos(x))
* sin(x0) = sin(x)cos(3pi/4)-cos(x)sin(3pi/4)
* = -1/sqrt(2) * (cos(x) + sin(x))
* To avoid cancellation, use
* sin(x) +- cos(x) = -cos(2x)/(sin(x) -+ cos(x))
* to compute the worse one.
*/
if(ix>0x48000000) z = (invsqrtpi*ss)/__ieee754_sqrtf(x);
else {
u = ponef(x); v = qonef(x);
z = invsqrtpi*(u*ss+v*cc)/__ieee754_sqrtf(x);
}
return z;
}
if(__builtin_expect(ix<=0x33000000, 0)) { /* x < 2**-25 */
z = -tpi / x;
if (__isinff (z))
__set_errno (ERANGE);
return z;
}
z = x*x;
u = U0[0]+z*(U0[1]+z*(U0[2]+z*(U0[3]+z*U0[4])));
v = one+z*(V0[0]+z*(V0[1]+z*(V0[2]+z*(V0[3]+z*V0[4]))));
return(x*(u/v) + tpi*(__ieee754_j1f(x)*__ieee754_logf(x)-one/x));
}
开发者ID:SvenDowideit，项目名称:clearlinux，代码行数:52，代码来源:e_j1f.c
注：本文中的GET_FLOAT_WORD函数示例由纯净天空整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。 |
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