newlib-cygwin/newlib/libm/machine/amdgcn/v64sf_fmod.c

148 lines
4.4 KiB
C

/*
* Copyright 2023 Siemens
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/* Based on newlib/libm/mathfp/sf_fmod.c in Newlib. */
#include "amdgcnmach.h"
DEF_VS_MATH_FUNC (v64sf, fmodf, v64sf x, v64sf y)
{
FUNCTION_INIT(v64sf);
v64si hx, hy, hz;
GET_FLOAT_WORD (hx, x, NO_COND);
GET_FLOAT_WORD (hy, y, NO_COND);
v64si sx = hx & 0x80000000; /* sign of x */
hx ^=sx; /* |x| */
hy &= 0x7fffffff; /* |y| */
v64sf zeroes = VECTOR_MERGE (VECTOR_INIT (-0.0f),
VECTOR_INIT (0.0f),
sx != 0);
/* purge off exception values */
VECTOR_IF ((hy == 0) | (hx >= 0x7f800000)
| (hy > 0x7f800000), cond) // y=0, or x not finite or y is NaN
VECTOR_RETURN ((x * y) / (x * y), cond);
VECTOR_ENDIF
VECTOR_IF (hx < hy, cond) // |x|<|y| return x
VECTOR_RETURN (x, cond);
VECTOR_ENDIF
VECTOR_IF (hx == hy, cond)
VECTOR_RETURN (zeroes, hx == hy); // |x|=|y| return x*0
VECTOR_ENDIF
/* determine ix = ilogb(x) */
v64si ix;
VECTOR_IF (hx < 0x00800000, cond) // subnormal x
ix = VECTOR_INIT (-126);
for (v64si i = (hx << 8);
!ALL_ZEROES_P (cond & (i > 0));
i <<= 1)
VECTOR_COND_MOVE (ix, ix - 1, cond & (i > 0));
VECTOR_ELSE (cond)
VECTOR_COND_MOVE (ix, (hx >> 23) - 127, cond);
VECTOR_ENDIF
/* determine iy = ilogb(y) */
v64si iy;
VECTOR_IF (hy < 0x00800000, cond) // subnormal y
iy = VECTOR_INIT (-126);
for (v64si i = (hy << 8); !ALL_ZEROES_P (cond & (i >= 0)); i <<= 1)
VECTOR_COND_MOVE (iy, iy - 1, cond & (i >= 0));
VECTOR_ELSE (cond)
VECTOR_COND_MOVE (iy, (hy >> 23) - 127, cond);
VECTOR_ENDIF
/* set up {hx,lx}, {hy,ly} and align y to x */
VECTOR_IF (ix >= -126, cond)
VECTOR_COND_MOVE (hx, 0x00800000 | (0x007fffff & hx), cond);
VECTOR_ELSE (cond) // subnormal x, shift x to normal
{
v64si n = -126 - ix;
VECTOR_COND_MOVE (hx, hx << n, cond);
}
VECTOR_ENDIF
VECTOR_IF (iy >= -126, cond)
VECTOR_COND_MOVE (hy, 0x00800000 | (0x007fffff & hy), cond);
VECTOR_ELSE (cond) // subnormal y, shift y to normal
{
v64si n = -126 - iy;
VECTOR_COND_MOVE (hy, hy << n, cond);
}
VECTOR_ENDIF
/* fix point fmod */
v64si n = ix - iy;
v64si cond = n != 0;
while (!ALL_ZEROES_P (cond))
{
hz = hx - hy;
VECTOR_IF2 (hz < 0, cond2, cond)
VECTOR_COND_MOVE (hx, hx + hx, cond2);
VECTOR_ELSE2 (cond2, cond)
VECTOR_IF2 (hz == 0, cond3, cond2) // return sign(x)*0
VECTOR_RETURN (zeroes, cond3);
VECTOR_ELSE2 (cond3, cond2)
VECTOR_COND_MOVE (hx, hz + hz, cond2);
VECTOR_ENDIF
VECTOR_ENDIF
n += cond; // Active lanes should be -1
cond &= (n != 0);
}
hz = hx - hy;
VECTOR_COND_MOVE (hx, hz, hz >= 0);
/* convert back to floating value and restore the sign */
VECTOR_RETURN (zeroes, hx == 0); // return sign(x)*0
cond = hx < 0x00800000;
while (!ALL_ZEROES_P (cond)) // normalize x
{
VECTOR_COND_MOVE (hx, hx + hx, cond);
iy += cond; // Active lanes should be -1
cond &= (hx < 0x00800000);
}
VECTOR_IF (iy >= -126, cond) // normalize output
VECTOR_COND_MOVE (hx, (hx - 0x00800000) | ((iy + 127) << 23), cond);
SET_FLOAT_WORD (x, hx | sx, cond);
VECTOR_ELSE (cond) // subnormal output */
n = -126 - iy;
hx >>= n;
SET_FLOAT_WORD (x, hx | sx, cond);
x *= VECTOR_INIT (1.0f); /* create necessary signal */
VECTOR_ENDIF
VECTOR_RETURN (x, NO_COND); /* exact output */
FUNCTION_RETURN;
}
DEF_VARIANTS2 (fmodf, sf, sf)