version 1.2, 2007/01/17 23:24:22 |
version 1.3, 2008/04/25 22:21:53 |
Line 35 static const double huge = 1.0e300; |
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Line 35 static const double huge = 1.0e300; |
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double |
double |
trunc(double x) |
trunc(double x) |
{ |
{ |
int32_t i0,i1,j0; |
int32_t i0,i1,jj0; |
uint32_t i; |
uint32_t i; |
EXTRACT_WORDS(i0,i1,x); |
EXTRACT_WORDS(i0,i1,x); |
j0 = ((i0>>20)&0x7ff)-0x3ff; |
jj0 = ((i0>>20)&0x7ff)-0x3ff; |
if(j0<20) { |
if(jj0<20) { |
if(j0<0) { /* raise inexact if x != 0 */ |
if(jj0<0) { /* raise inexact if x != 0 */ |
if(huge+x>0.0) {/* |x|<1, so return 0*sign(x) */ |
if(huge+x>0.0) {/* |x|<1, so return 0*sign(x) */ |
i0 &= 0x80000000U; |
i0 &= 0x80000000U; |
i1 = 0; |
i1 = 0; |
} |
} |
} else { |
} else { |
i = (0x000fffff)>>j0; |
i = (0x000fffff)>>jj0; |
if(((i0&i)|i1)==0) return x; /* x is integral */ |
if(((i0&i)|i1)==0) return x; /* x is integral */ |
if(huge+x>0.0) { /* raise inexact flag */ |
if(huge+x>0.0) { /* raise inexact flag */ |
i0 &= (~i); i1=0; |
i0 &= (~i); i1=0; |
} |
} |
} |
} |
} else if (j0>51) { |
} else if (jj0>51) { |
if(j0==0x400) return x+x; /* inf or NaN */ |
if(jj0==0x400) return x+x; /* inf or NaN */ |
else return x; /* x is integral */ |
else return x; /* x is integral */ |
} else { |
} else { |
i = ((u_int32_t)(0xffffffff))>>(j0-20); |
i = ((u_int32_t)(0xffffffff))>>(jj0-20); |
if((i1&i)==0) return x; /* x is integral */ |
if((i1&i)==0) return x; /* x is integral */ |
if(huge+x>0.0) /* raise inexact flag */ |
if(huge+x>0.0) /* raise inexact flag */ |
i1 &= (~i); |
i1 &= (~i); |