| /* |
| * Copyright (c) 2014 Advanced Micro Devices, Inc. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| #include "math32.h" |
| |
| __attribute__((overloadable, always_inline, weak)) float |
| ldexp(float x, int n) |
| { |
| #if 0 |
| // This treats subnormals as zeros |
| int i = as_int(x); |
| int e = (i >> 23) & 0xff; |
| int m = i & 0x007fffff; |
| int s = i & 0x80000000; |
| int v = add_sat(e, n); |
| v = clamp(v, 0, 0xff); |
| int mr = e == 0 | v == 0 | v == 0xff ? 0 : m; |
| int c = e == 0xff; |
| mr = c ? m : mr; |
| int er = c ? e : v; |
| er = e ? er : e; |
| return as_float( s | (er << 23) | mr ); |
| #endif |
| |
| |
| /* supports denormal values */ |
| const int multiplier = 24; |
| float val_f; |
| uint val_ui; |
| uint sign; |
| int exponent; |
| val_ui = as_uint(x); |
| sign = val_ui & 0x80000000; |
| val_ui = val_ui & 0x7fffffff;/* remove the sign bit */ |
| int val_x = val_ui; |
| |
| exponent = val_ui >> 23; /* get the exponent */ |
| int dexp = exponent; |
| |
| |
| /* denormal support */ |
| int fbh = 127 - (as_uint((float)(as_float(val_ui | 0x3f800000) - 1.0)) >> 23); |
| int dexponent = 25 - fbh; |
| uint dval_ui = (( (val_ui << fbh) & 0x007fffff) | (dexponent << 23)); |
| int ex = dexponent + n - multiplier; |
| dexponent = ex; |
| uint val = sign | (ex << 23) | (dval_ui & 0x007fffff); |
| int ex1 = dexponent + multiplier; |
| ex1 = -ex1 +25; |
| dval_ui = (((dval_ui & 0x007fffff )| 0x800000) >> ex1); |
| dval_ui = dexponent > 0 ? val :dval_ui; |
| dval_ui = dexponent > 254 ? 0x7f800000 :dval_ui; /*overflow*/ |
| dval_ui = dexponent < -multiplier ? 0 : dval_ui; /*underflow*/ |
| dval_ui = dval_ui | sign; |
| val_f = as_float(dval_ui); |
| |
| exponent += n; |
| |
| val = sign | (exponent << 23) | (val_ui & 0x007fffff); |
| ex1 = exponent + multiplier; |
| ex1 = -ex1 +25; |
| val_ui = (((val_ui & 0x007fffff )| 0x800000) >> ex1); |
| val_ui = exponent > 0 ? val :val_ui; |
| val_ui = exponent > 254 ? 0x7f800000 :val_ui; /*overflow*/ |
| val_ui = exponent < -multiplier ? 0 : val_ui; /*underflow*/ |
| val_ui = val_ui | sign; |
| |
| val_ui = dexp == 0? dval_ui : val_ui; |
| val_f = as_float(val_ui); |
| |
| |
| val_f = isnan(x) | isinf(x) | val_x == 0 ? x : val_f; |
| return val_f; |
| |
| |
| } |