diff options
Diffstat (limited to 'src/math/__rem_pio2f.c')
| -rw-r--r-- | src/math/__rem_pio2f.c | 34 |
1 files changed, 12 insertions, 22 deletions
diff --git a/src/math/__rem_pio2f.c b/src/math/__rem_pio2f.c index 5bdeb529..838e1fca 100644 --- a/src/math/__rem_pio2f.c +++ b/src/math/__rem_pio2f.c @@ -34,42 +34,32 @@ pio2_1t = 1.58932547735281966916e-08; /* 0x3E5110b4, 0x611A6263 */ int __rem_pio2f(float x, double *y) { - double w,r,fn; - double tx[1],ty[1]; - float z; - int32_t e0,n,ix,hx; + union {float f; uint32_t i;} u = {x}; + double tx[1],ty[1],fn; + uint32_t ix; + int n, sign, e0; - GET_FLOAT_WORD(hx, x); - ix = hx & 0x7fffffff; + ix = u.i & 0x7fffffff; /* 25+53 bit pi is good enough for medium size */ if (ix < 0x4dc90fdb) { /* |x| ~< 2^28*(pi/2), medium size */ /* Use a specialized rint() to get fn. Assume round-to-nearest. */ fn = x*invpio2 + 0x1.8p52; fn = fn - 0x1.8p52; -// FIXME -#ifdef HAVE_EFFICIENT_IRINT - n = irint(fn); -#else n = (int32_t)fn; -#endif - r = x - fn*pio2_1; - w = fn*pio2_1t; - *y = r - w; + *y = x - fn*pio2_1 - fn*pio2_1t; return n; } - /* - * all other (large) arguments - */ if(ix>=0x7f800000) { /* x is inf or NaN */ *y = x-x; return 0; } - /* set z = scalbn(|x|,ilogb(|x|)-23) */ - e0 = (ix>>23) - 150; /* e0 = ilogb(|x|)-23; */ - SET_FLOAT_WORD(z, ix - ((int32_t)(e0<<23))); - tx[0] = z; + /* scale x into [2^23, 2^24-1] */ + sign = u.i>>31; + e0 = (ix>>23) - (0x7f+23); /* e0 = ilogb(|x|)-23, positive */ + u.i = ix - (e0<<23); + tx[0] = u.f; n = __rem_pio2_large(tx,ty,e0,1,0); - if (hx < 0) { + if (sign) { *y = -ty[0]; return -n; } |