diff options
Diffstat (limited to 'newlib')
| -rw-r--r-- | newlib/libm/math/e_pow.c | 37 |
1 files changed, 18 insertions, 19 deletions
diff --git a/newlib/libm/math/e_pow.c b/newlib/libm/math/e_pow.c index 258cca8..f02f76d 100644 --- a/newlib/libm/math/e_pow.c +++ b/newlib/libm/math/e_pow.c @@ -107,7 +107,7 @@ ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/ #endif { double z,ax,z_h,z_l,p_h,p_l; - double y1,t1,t2,r,s,t,u,v,w; + double y1,t1,t2,r,s,sign,t,u,v,w; __int32_t i,j,k,yisint,n; __int32_t hx,hy,ix,iy; __uint32_t lx,ly; @@ -184,23 +184,26 @@ ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/ return z; } } - + /* (x<0)**(non-int) is NaN */ - /* REDHAT LOCAL: This used to be - if((((hx>>31)+1)|yisint)==0) return (x-x)/(x-x); - but ANSI C says a right shift of a signed negative quantity is - implementation defined. */ - if(((((__uint32_t)hx>>31)-1)|yisint)==0) return (x-x)/(x-x); + + n = ((uint32_t)hx >> 31U) - 1U; + if ((n | yisint) == 0) return (x-x)/(x-x); + + sign = one; /* (sign of result -ve**odd) = -1 else = 1 */ + if ((n | (yisint - 1)) == 0) { + sign = -one; /* (-ve)**(odd int) */ + } /* |y| is huge */ if(iy>0x41e00000) { /* if |y| > 2**31 */ - if(iy>0x43f00000){ /* if |y| > 2**64, must o/uflow */ + if(iy>0x43f00000){ /* if |y| > 2**64, must o/uflow and y is an even integer */ if(ix<=0x3fefffff) return (hy<0)? __math_oflow(0):__math_uflow(0); if(ix>=0x3ff00000) return (hy>0)? __math_oflow(0):__math_uflow(0); } /* over/underflow if x is not close to one */ - if(ix<0x3fefffff) return (hy<0)? __math_oflow(0):__math_uflow(0); - if(ix>0x3ff00000) return (hy>0)? __math_oflow(0):__math_uflow(0); + if(ix<0x3fefffff) return (hy<0)? __math_oflow(sign<0):__math_uflow(sign<0); + if(ix>0x3ff00000) return (hy>0)? __math_oflow(sign<0):__math_uflow(sign<0); /* now |1-x| is tiny <= 2**-20, suffice to compute log(x) by x-x^2/2+x^3/3-x^4/4 */ t = ax-1; /* t has 20 trailing zeros */ @@ -260,10 +263,6 @@ ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/ t2 = z_l-(((t1-t)-dp_h[k])-z_h); } - s = one; /* s (sign of result -ve**odd) = -1 else = 1 */ - if(((((__uint32_t)hx>>31)-1)|(yisint-1))==0) - s = -one;/* (-ve)**(odd int) */ - /* split up y into y1+y2 and compute (y1+y2)*(t1+t2) */ y1 = y; SET_LOW_WORD(y1,0); @@ -273,15 +272,15 @@ ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/ EXTRACT_WORDS(j,i,z); if (j>=0x40900000) { /* z >= 1024 */ if(((j-0x40900000)|i)!=0) /* if z > 1024 */ - return __math_oflow(s<0); /* overflow */ + return __math_oflow(sign<0); /* overflow */ else { - if(p_l+ovt>z-p_h) return __math_oflow(s<0); /* overflow */ + if(p_l+ovt>z-p_h) return __math_oflow(sign<0); /* overflow */ } } else if((j&0x7fffffff)>=0x4090cc00 ) { /* z <= -1075 */ if(((j-0xc090cc00)|i)!=0) /* z < -1075 */ - return __math_uflow(s<0); /* underflow */ + return __math_uflow(sign<0); /* underflow */ else { - if(p_l<=z-p_h) return __math_uflow(s<0); /* underflow */ + if(p_l<=z-p_h) return __math_uflow(sign<0); /* underflow */ } } /* @@ -313,7 +312,7 @@ ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/ j += (n<<20); if((j>>20)<=0) z = scalbn(z,(int)n); /* subnormal output */ else SET_HIGH_WORD(z,j); - return s*z; + return sign*z; } #endif /* defined(_DOUBLE_IS_32BITS) */ |