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Diffstat (limited to 'newlib/libm/machine/spu/headers/scalbnf4.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/scalbnf4.h | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/scalbnf4.h b/newlib/libm/machine/spu/headers/scalbnf4.h new file mode 100644 index 000000000..718a8f9f9 --- /dev/null +++ b/newlib/libm/machine/spu/headers/scalbnf4.h @@ -0,0 +1,113 @@ +/* -------------------------------------------------------------- */ +/* (C)Copyright 2006,2007, */ +/* International Business Machines Corporation, */ +/* Sony Computer Entertainment, Incorporated, */ +/* Toshiba 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 _SCALBNF4_H_ +#define _SCALBNF4_H_ 1 + +#include <spu_intrinsics.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 _scalbnf4(vector float x, vector signed int exp) +{ + vec_int4 x_exp; + vec_uint4 zero; + vec_uint4 overflow; + vec_uint4 exp_mask = (vec_uint4)spu_splats(0x7F800000); + vec_float4 out; + + /* Extract exponent from x. If the exponent is 0, then + * x is either 0 or a denorm and x*2^exp is a zero. + */ + x_exp = spu_and(spu_rlmask((vec_int4)x, -23), 0xFF); + zero = spu_cmpeq(x_exp, 0); + + /* Compute the expected exponent and determine if the + * result is within range. + */ + x_exp = spu_add(exp, x_exp); + + /* Check for zero or overflow of result. + * Note: set high bit of flags = 0, since we have to + * return -0 when x = -0 + */ + zero = spu_rlmask(spu_orc(zero, spu_cmpgt(x_exp, 0)), -1); + overflow = spu_rlmask(spu_cmpgt(x_exp, 255), -1); + + /* Merge the expect exponent with x's mantissa. Zero the + * result if underflow and force to max if overflow. + */ + out = spu_sel(x, (vec_float4)spu_rl(x_exp, 23), exp_mask); + out = spu_andc(out, (vec_float4)zero); + out = spu_or(out, (vec_float4)overflow); + + return out; +} + +#endif /* _SCALBNF4_H_ */ +#endif /* __SPU__ */ |