diff options
Diffstat (limited to 'newlib/libm/machine/spu/headers/nextafterd2.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/nextafterd2.h | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/nextafterd2.h b/newlib/libm/machine/spu/headers/nextafterd2.h new file mode 100644 index 000000000..78238487a --- /dev/null +++ b/newlib/libm/machine/spu/headers/nextafterd2.h @@ -0,0 +1,124 @@ +/* -------------------------------------------------------------- */ +/* (C)Copyright 2006,2007, */ +/* International Business Machines Corporation */ +/* All Rights Reserved. */ +/* */ +/* Redistribution and use in source and binary forms, with or */ +/* without modification, are permitted provided that the */ +/* following conditions are met: */ +/* */ +/* - Redistributions of source code must retain the above copyright*/ +/* notice, this list of conditions and the following disclaimer. */ +/* */ +/* - Redistributions in binary form must reproduce the above */ +/* copyright notice, this list of conditions and the following */ +/* disclaimer in the documentation and/or other materials */ +/* provided with the distribution. */ +/* */ +/* - Neither the name of IBM Corporation nor the names of its */ +/* contributors may be used to endorse or promote products */ +/* derived from this software without specific prior written */ +/* permission. */ +/* Redistributions of source code must retain the above copyright */ +/* notice, this list of conditions and the following disclaimer. */ +/* */ +/* Redistributions in binary form must reproduce the above */ +/* copyright notice, this list of conditions and the following */ +/* disclaimer in the documentation and/or other materials */ +/* provided with the distribution. */ +/* */ +/* Neither the name of IBM Corporation nor the names of its */ +/* contributors may be used to endorse or promote products */ +/* derived from this software without specific prior written */ +/* permission. */ +/* */ +/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND */ +/* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, */ +/* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */ +/* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE */ +/* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR */ +/* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */ +/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT */ +/* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; */ +/* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) */ +/* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN */ +/* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR */ +/* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */ +/* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ +/* -------------------------------------------------------------- */ +/* PROLOG END TAG zYx */ +#ifdef __SPU__ +#ifndef _NEXTAFTERD2_H_ +#define _NEXTAFTERD2_H_ 1 + +#include <spu_intrinsics.h> + +/* + * FUNCTION + * vector double _nextafterd2(vector double x, vector double y) + * + * DESCRIPTION + * The nextafterf4 function returns a vector containing the next representable + * floating-point number after the element of x, in the direction of the + * corresponding element y. + * + * Special Cases: + * - nextafter(NaN, y) = NaN + * - nextafter(x, NaN) = NaN + * - x = largest finite value, y = infinity, result is undefined + * - x = largest finite negative value, y = -infinity, result is undefined + * - x != y, and result = 0, considered an underflow + * + */ + +static __inline vector double _nextafterd2(vector double x, vector double y) +{ + vec_double2 n1ulp = (vec_double2)spu_splats(0x8000000000000001ull); + vec_double2 zerod = spu_splats(0.0); + vec_llong2 one = spu_splats(1ll); + vec_ullong2 xlt0, xgty, xeqy, xeq0; + vec_llong2 xllong; + vec_llong2 delta, deltap1; + vec_double2 result; + + /* Compiler Bug. Replace xtmp/ytmp with x/y when spu_cmpgt(x,y) doesn't change x/y!*/ + volatile vec_double2 xtmp = x; + volatile vec_double2 ytmp = y; + + /* + * The idea here is to treat x as a signed long long value, which allows us to + * add or subtact one to/from it to get the next representable value. + */ + + xeq0 = spu_cmpeq(xtmp, zerod); + xlt0 = spu_cmpgt(zerod, xtmp); + xeqy = spu_cmpeq(xtmp, ytmp); + xgty = spu_cmpgt(xtmp, ytmp); + + /* If x = -0.0, set x = 0.0 */ + x = spu_andc(x, (vec_double2)xeq0); + + xllong = (vec_llong2)x; + + /* Determine value to add to x */ + delta = (vec_llong2)spu_xor(xgty, xlt0); + deltap1 = delta + one; + delta = spu_sel(deltap1, delta, (vec_ullong2)delta); + + xllong = xllong + delta; + + /* Fix the case of x = 0, and answer should be -1 ulp */ + result = spu_sel((vec_double2)xllong, n1ulp, spu_and((vec_ullong2)delta, xeq0)); + + /* + * Special Cases + */ + + /* x = y */ + result = spu_sel(result, y, xeqy); + + return result; +} + +#endif /* _NEXTAFTERD2_H_ */ +#endif /* __SPU__ */ |