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9e97f239ea
Remove the wordsize-64 implementations by merging them into the main dbl-64 directory. The second patch just moves all wordsize-64 files and removes a few wordsize-64 uses in comments and Implies files. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/* Rewritten for 64-bit machines by Ulrich Drepper <drepper@gmail.com>. */
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/*
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* ====================================================
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* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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*
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* Developed at SunPro, a Sun Microsystems, Inc. business.
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* Permission to use, copy, modify, and distribute this
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* software is freely granted, provided that this notice
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* is preserved.
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* ====================================================
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*/
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/*
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* __ieee754_fmod(x,y)
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* Return x mod y in exact arithmetic
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* Method: shift and subtract
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*/
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#include <math.h>
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#include <math_private.h>
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#include <stdint.h>
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#include <libm-alias-finite.h>
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static const double one = 1.0, Zero[] = {0.0, -0.0,};
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double
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__ieee754_fmod (double x, double y)
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{
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int32_t n,ix,iy;
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int64_t hx,hy,hz,sx,i;
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EXTRACT_WORDS64(hx,x);
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EXTRACT_WORDS64(hy,y);
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sx = hx&UINT64_C(0x8000000000000000); /* sign of x */
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hx ^=sx; /* |x| */
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hy &= UINT64_C(0x7fffffffffffffff); /* |y| */
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/* purge off exception values */
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if(__builtin_expect(hy==0
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|| hx >= UINT64_C(0x7ff0000000000000)
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|| hy > UINT64_C(0x7ff0000000000000), 0))
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/* y=0,or x not finite or y is NaN */
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return (x*y)/(x*y);
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if(__builtin_expect(hx<=hy, 0)) {
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if(hx<hy) return x; /* |x|<|y| return x */
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return Zero[(uint64_t)sx>>63]; /* |x|=|y| return x*0*/
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}
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/* determine ix = ilogb(x) */
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if(__builtin_expect(hx<UINT64_C(0x0010000000000000), 0)) {
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/* subnormal x */
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for (ix = -1022,i=(hx<<11); i>0; i<<=1) ix -=1;
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} else ix = (hx>>52)-1023;
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/* determine iy = ilogb(y) */
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if(__builtin_expect(hy<UINT64_C(0x0010000000000000), 0)) { /* subnormal y */
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for (iy = -1022,i=(hy<<11); i>0; i<<=1) iy -=1;
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} else iy = (hy>>52)-1023;
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/* set up hx, hy and align y to x */
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if(__builtin_expect(ix >= -1022, 1))
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hx = UINT64_C(0x0010000000000000)|(UINT64_C(0x000fffffffffffff)&hx);
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else { /* subnormal x, shift x to normal */
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n = -1022-ix;
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hx<<=n;
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}
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if(__builtin_expect(iy >= -1022, 1))
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hy = UINT64_C(0x0010000000000000)|(UINT64_C(0x000fffffffffffff)&hy);
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else { /* subnormal y, shift y to normal */
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n = -1022-iy;
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hy<<=n;
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}
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/* fix point fmod */
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n = ix - iy;
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while(n--) {
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hz=hx-hy;
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if(hz<0){hx = hx+hx;}
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else {
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if(hz==0) /* return sign(x)*0 */
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return Zero[(uint64_t)sx>>63];
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hx = hz+hz;
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}
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}
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hz=hx-hy;
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if(hz>=0) {hx=hz;}
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/* convert back to floating value and restore the sign */
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if(hx==0) /* return sign(x)*0 */
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return Zero[(uint64_t)sx>>63];
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while(hx<UINT64_C(0x0010000000000000)) { /* normalize x */
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hx = hx+hx;
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iy -= 1;
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}
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if(__builtin_expect(iy>= -1022, 1)) { /* normalize output */
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hx = ((hx-UINT64_C(0x0010000000000000))|((uint64_t)(iy+1023)<<52));
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INSERT_WORDS64(x,hx|sx);
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} else { /* subnormal output */
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n = -1022 - iy;
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hx>>=n;
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INSERT_WORDS64(x,hx|sx);
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x *= one; /* create necessary signal */
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}
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return x; /* exact output */
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}
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libm_alias_finite (__ieee754_fmod, __fmod)
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