| |
| /* |
| * Copyright (C) 2008-2009 Advanced Micro Devices, Inc. All Rights Reserved. |
| * |
| * This file is part of libacml_mv. |
| * |
| * libacml_mv is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * libacml_mv is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with libacml_mv. If not, see |
| * <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| |
| #ifdef WIN64 |
| #include <fpieee.h> |
| #else |
| #include <errno.h> |
| #endif |
| |
| #include <math.h> |
| #include "../inc/libm_amd.h" |
| #include "../inc/libm_util_amd.h" |
| |
| #include "../inc/libm_special.h" |
| |
| double FN_PROTOTYPE(ldexp)(double x, int n) |
| { |
| UT64 val; |
| unsigned int sign; |
| int exponent; |
| val.f64 = x; |
| sign = val.u32[1] & 0x80000000; |
| val.u32[1] = val.u32[1] & 0x7fffffff; /* remove the sign bit */ |
| |
| if((val.u32[1] & 0x7ff00000)== 0x7ff00000)/* x= nan or x = +-inf*/ |
| return x; |
| |
| if((val.u64 == 0x0000000000000000) || (n==0)) |
| return x; /* x= +-0 or n= 0*/ |
| |
| exponent = val.u32[1] >> 20; /* get the exponent */ |
| |
| if(exponent == 0)/*x is denormal*/ |
| { |
| val.f64 = val.f64 * VAL_2PMULTIPLIER_DP;/*multiply by 2^53 to bring it to the normal range*/ |
| exponent = val.u32[1] >> 20; /* get the exponent */ |
| exponent = exponent + n - MULTIPLIER_DP; |
| if(exponent < -MULTIPLIER_DP)/*underflow*/ |
| { |
| val.u32[1] = sign | 0x00000000; |
| val.u32[0] = 0x00000000; |
| __amd_handle_error(UNDERFLOW, ERANGE, "ldexp", x,(double)n ,val.f64); |
| |
| return val.f64; |
| } |
| if(exponent > 2046)/*overflow*/ |
| { |
| val.u32[1] = sign | 0x7ff00000; |
| val.u32[0] = 0x00000000; |
| __amd_handle_error(OVERFLOW, ERANGE, "ldexp", x,(double)n ,val.f64); |
| |
| return val.f64; |
| } |
| |
| exponent += MULTIPLIER_DP; |
| val.u32[1] = sign | (exponent << 20) | (val.u32[1] & 0x000fffff); |
| val.f64 = val.f64 * VAL_2PMMULTIPLIER_DP; |
| return val.f64; |
| } |
| |
| exponent += n; |
| |
| if(exponent < -MULTIPLIER_DP)/*underflow*/ |
| { |
| val.u32[1] = sign | 0x00000000; |
| val.u32[0] = 0x00000000; |
| |
| __amd_handle_error(UNDERFLOW, ERANGE, "ldexp", x,(double)n ,val.f64); |
| |
| |
| return val.f64; |
| } |
| |
| if(exponent < 1)/*x is normal but output is debnormal*/ |
| { |
| exponent += MULTIPLIER_DP; |
| val.u32[1] = sign | (exponent << 20) | (val.u32[1] & 0x000fffff); |
| val.f64 = val.f64 * VAL_2PMMULTIPLIER_DP; |
| return val.f64; |
| } |
| |
| if(exponent > 2046)/*overflow*/ |
| { |
| val.u32[1] = sign | 0x7ff00000; |
| val.u32[0] = 0x00000000; |
| __amd_handle_error(OVERFLOW, ERANGE, "ldexp", x,(double)n ,val.f64); |
| |
| |
| return val.f64; |
| } |
| |
| val.u32[1] = sign | (exponent << 20) | (val.u32[1] & 0x000fffff); |
| return val.f64; |
| } |
| |
| |
| |