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Diffstat (limited to 'newlib/libm/machine/spu/headers/logbf4.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/logbf4.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/logbf4.h b/newlib/libm/machine/spu/headers/logbf4.h new file mode 100644 index 000000000..d3dbeeb93 --- /dev/null +++ b/newlib/libm/machine/spu/headers/logbf4.h @@ -0,0 +1,111 @@ +/* -------------------------------------------------------------- */ +/* (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 _LOGBF4_H_ +#define _LOGBF4_H_ 1 + +#include <spu_intrinsics.h> +#include <vec_types.h> + +/* + * FUNCTION + * vector float _scalbnf4(vector float x, vector signed int exp) + * + * DESCRIPTION + * The _scalbnf4 function returns a vector containing each element of x + * multiplied by 2^n computed efficiently. This function is computed + * without the assistance of any floating point operations and as such + * does not set any floating point exceptions. + * + * Special Cases: + * - if the exponent is 0, then x is either 0 or a subnormal, and the + * result will be returned as 0. + * - if the result if underflows, it will be returned as 0. + * - if the result overflows, it will be returned as FLT_MAX. + * + */ +static __inline vector float _logbf4(vector float x) +{ + vec_uint4 lzero = (vector unsigned int) {0, 0, 0, 0}; + vec_uint4 exp_mask = (vector unsigned int) {0xFF, 0xFF, 0xFF, 0xFF}; + vec_int4 exp_shift = (vector signed int) { -23, -23, -23, -23}; + vec_int4 exp_bias = (vector signed int) {-127, -127, -127, -127}; + vec_uint4 sign_mask = (vector unsigned int) {0x80000000, 0x80000000, + 0x80000000, 0x80000000}; + vec_uint4 linf = (vector unsigned int) {0x7F800000, 0x7F800000, + 0x7F800000, 0x7F800000}; + vec_uint4 lminf = (vector unsigned int) {0xFF800000, 0xFF800000, + 0xFF800000, 0xFF800000}; + vec_uint4 exp; + vec_uint4 xabs; + vec_float4 exp_unbias; + + + xabs = spu_andc((vec_uint4)x, sign_mask); + + exp = spu_and(spu_rlmask((vec_uint4)x, exp_shift), exp_mask); + exp_unbias = spu_convtf(spu_add((vec_int4)exp, exp_bias), 0); + + /* Zero */ + exp_unbias = spu_sel(exp_unbias, (vec_float4)lminf, (vec_uint4)spu_cmpeq(xabs, lzero)); + + /* NaN */ + exp_unbias = spu_sel(exp_unbias, x, (vec_uint4)spu_cmpgt(xabs, linf)); + + /* Infinite */ + exp_unbias = spu_sel(exp_unbias, (vec_float4)linf, (vec_uint4)spu_cmpeq(xabs, linf)); + + return (exp_unbias); +} + +#endif /* _LOGBF4_H_ */ + +#endif /* __SPU__ */ |