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Diffstat (limited to 'newlib/libm/machine/spu/headers/exp2d2.h')
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1 files changed, 164 insertions, 0 deletions
diff --git a/newlib/libm/machine/spu/headers/exp2d2.h b/newlib/libm/machine/spu/headers/exp2d2.h new file mode 100644 index 000000000..27b0f31c9 --- /dev/null +++ b/newlib/libm/machine/spu/headers/exp2d2.h @@ -0,0 +1,164 @@ +/* -------------------------------------------------------------- */ +/* (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 _EXP2D2_H_ +#define _EXP2D2_H_ 1 + +#include <spu_intrinsics.h> + + +/* + * FUNCTION + * vector double _exp2d2(vector double x) + * + * DESCRIPTION + * _exp2d2 computes 2 raised to the input x for each + * of the double word elements of x. Computation is + * performed by observing the 2^(a+b) = 2^a * 2^b. + * We decompose x into a and b (above) by letting. + * a = ceil(x), b = x - a; + * + * 2^a is easily computed by placing a into the exponent + * or a floating point number whose mantissa is all zeros. + * + * 2^b is computed using the polynomial approximation. + * + * __13_ + * \ + * \ + * 2^x = / Ci*x^i + * /____ + * i=0 + * + * for x in the range 0.0 to 1.0. + * + */ +#define EXP_C00 1.0 +#define EXP_C01 6.93147180559945286227e-01 +#define EXP_C02 2.40226506959100694072e-01 +#define EXP_C03 5.55041086648215761801e-02 +#define EXP_C04 9.61812910762847687873e-03 +#define EXP_C05 1.33335581464284411157e-03 +#define EXP_C06 1.54035303933816060656e-04 +#define EXP_C07 1.52527338040598376946e-05 +#define EXP_C08 1.32154867901443052734e-06 +#define EXP_C09 1.01780860092396959520e-07 +#define EXP_C10 7.05491162080112087744e-09 +#define EXP_C11 4.44553827187081007394e-10 +#define EXP_C12 2.56784359934881958182e-11 +#define EXP_C13 1.36914888539041240648e-12 + +static __inline vector double _exp2d2(vector double vx) +{ + vec_int4 ix, exp; + vec_uint4 overflow, underflow; + vec_float4 vxf; + vec_double2 p1, p2, x2, x4, x8; + vec_double2 vy, vxw, out_of_range; + + /* Compute: vxw = x - ceil(x) + */ + vxw = spu_add(vx, spu_splats(0.5)); + vxf = spu_roundtf(vxw); + ix = spu_convts(vxf, 0); + ix = spu_add(ix, (vec_int4)spu_andc(spu_cmpgt(spu_splats(0.0f), vxf), spu_cmpeq(ix, spu_splats((int)0x80000000)))); + vxf = spu_convtf(ix, 0); + vxw = spu_sub(vx, spu_extend(vxf)); + + /* Detect overflow and underflow. If overflow, force the result + * to infinity (at the end). + */ + exp = spu_shuffle(ix, ix, ((vec_uchar16) { 0,1,2,3, 0,1,2,3, 8,9,10,11, 8,9,10,11 })); + + overflow = spu_cmpgt(exp, 1023); + underflow = spu_cmpgt(exp, -1023); + out_of_range = (vec_double2)spu_and(overflow, ((vec_uint4) { 0x7FF00000, 0, 0x7FF00000, 0 })); + + /* Calculate the result by evaluating the 13th order polynomial. + * For efficiency, the polynomial is broken into two parts and + * evaluate then using nested + * + * result = (((((c13*x + c12)*x + c11)*x + c10)*x + c9)*x + c8)*x^8 + + * ((((((c7*x + c6)*x + c5)*x + c4)*x + c3)*x + c2)*x + c1)*x + c0 + */ + p2 = spu_madd(spu_splats(EXP_C07), vxw, spu_splats(EXP_C06)); + p1 = spu_madd(spu_splats(EXP_C13), vxw, spu_splats(EXP_C12)); + x2 = spu_mul(vxw, vxw); + p2 = spu_madd(vxw, p2, spu_splats(EXP_C05)); + p1 = spu_madd(vxw, p1, spu_splats(EXP_C11)); + x4 = spu_mul(x2, x2); + p2 = spu_madd(vxw, p2, spu_splats(EXP_C04)); + p1 = spu_madd(vxw, p1, spu_splats(EXP_C10)); + p2 = spu_madd(vxw, p2, spu_splats(EXP_C03)); + p1 = spu_madd(vxw, p1, spu_splats(EXP_C09)); + x8 = spu_mul(x4, x4); + p2 = spu_madd(vxw, p2, spu_splats(EXP_C02)); + p1 = spu_madd(vxw, p1, spu_splats(EXP_C08)); + p2 = spu_madd(vxw, p2, spu_splats(EXP_C01)); + p2 = spu_madd(vxw, p2, spu_splats(EXP_C00)); + vy = spu_madd(x8, p1, p2); + + /* Align the integer integer portion of x with the exponent. + */ + ix = spu_sl(ix, ((vec_uint4) { 20, 32, 20, 32 })); + vy = (vec_double2)spu_add((vec_int4)vy, ix); + + /* Select the result if not overflow or underflow. Otherwise select the + * the out of range value. + */ + return (spu_sel(vy, out_of_range, (vec_ullong2)spu_orc(overflow, underflow))); +} + +#endif /* _EXP2D2_H_ */ +#endif /* __SPU__ */ |