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Diffstat (limited to 'newlib/libm/machine/spu/headers/powf4.h')
| -rw-r--r-- | newlib/libm/machine/spu/headers/powf4.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/powf4.h b/newlib/libm/machine/spu/headers/powf4.h new file mode 100644 index 000000000..9eec44b32 --- /dev/null +++ b/newlib/libm/machine/spu/headers/powf4.h @@ -0,0 +1,132 @@ +/* -------------------------------------------------------------- */ +/* (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 _POWF4_H_ +#define _POWF4_H_ 1 + +#include <spu_intrinsics.h> +#include <vec_types.h> + +#include "exp2f4.h" +#include "log2f4.h" + +/* + * FUNCTION + * vector float _powf4(vector float x, vector float y) + * + * DESCRIPTION + * The _powf4 function computes x raised to the power y for the set of + * vectors. The powf4 function is computed as by decomposing + * the problem into: + * + * x^y = 2^(y*log2(x)) + * + */ +static __inline vector float _powf4(vector float x, vector float y) +{ + vec_uint4 y_exp; + vec_uint4 y_mantissa; + vec_uint4 mant_shift; + vec_uint4 y_is_int; + vec_uint4 y_is_odd; + vec_uint4 x_sign_bit; + vec_uint4 zero = (vec_uint4)spu_splats(0); + vec_uint4 bit0 = (vec_uint4)spu_splats(0x80000000); + vec_int4 error = spu_splats(-1); + vec_float4 out; + + y_exp = spu_and(spu_rlmask((vec_uint4)y, -23), 0x000000FF); + + /* Need the implied bit in the mantissa to catch + * y = 1 case later + */ + y_mantissa = spu_or(spu_sl((vec_uint4)y, (unsigned int)8), bit0); + + x_sign_bit = spu_and((vec_uint4)x, bit0); + + /* We are going to shift the mantissa over enough to + * determine if we have an integer. + */ + mant_shift = spu_add(y_exp, -127); + + + /* Leave the lowest-order integer bit of mantissa on the + * high end so we can see if the integer is odd. + */ + y_mantissa = spu_sl(y_mantissa, mant_shift); + + y_is_int = spu_cmpeq(spu_andc(y_mantissa, bit0), 0); + y_is_int = spu_and(y_is_int, spu_cmpgt(y_exp, 126)); + + y_is_odd = spu_and(spu_cmpeq(y_mantissa, bit0), y_is_int); + + out = _exp2f4(spu_mul(y, _log2f4(spu_andc(x, (vec_float4)bit0)))); + + /* x < 0 is only ok when y integer + */ + out = spu_sel(out, (vec_float4)error, + spu_andc(spu_cmpeq(x_sign_bit, bit0), y_is_int)); + + /* Preserve the sign of x if y is an odd integer + */ + out = spu_sel(out, spu_or(out, (vec_float4)x_sign_bit), y_is_odd); + + /* x = anything, y = +/- 0, returns 1 + */ + out = spu_sel(out, spu_splats(1.0f), spu_cmpabseq(y, (vec_float4)zero)); + + return(out); +} + +#endif /* _POWF4_H_ */ +#endif /* __SPU__ */ |