| /* |
| (C) Copyright 2001,2006, |
| 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 names of the copyright holders nor the names of their |
| 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. |
| */ |
| #ifndef _SCALBNF_H_ |
| #define _SCALBNF_H_ 1 |
| |
| #include <spu_intrinsics.h> |
| #include "headers/vec_literal.h" |
| |
| /* scalbnf computes x * 2^exp. This function is computed without |
| * the assistence of any floating point operations and as such does |
| * not set any floating point exceptions. |
| */ |
| static __inline float _scalbnf(float x, int exp) |
| { |
| vec_int4 x_exp; |
| vec_uint4 zero, overflow; |
| vec_uint4 exp_mask = VEC_SPLAT_U32(0x7F800000); |
| vec_float4 in, out; |
| |
| in = spu_promote(x, 0); |
| |
| /* 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)in, -23), 0xFF); |
| |
| zero = spu_cmpeq(x_exp, 0); |
| |
| /* Compute the expected exponent and determine if the |
| * result is within range. |
| */ |
| x_exp = spu_add(spu_promote(exp, 0), x_exp); |
| |
| zero = spu_orc(zero, spu_cmpgt(x_exp, 0)); |
| |
| 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(in, (vec_float4)spu_rl(x_exp, 23), exp_mask); |
| out = spu_andc(out, (vec_float4)zero); |
| out = spu_or(out, (vec_float4)overflow); |
| |
| return (spu_extract(out, 0)); |
| } |
| #endif /* _SCALBNF_H_ */ |