| /* |
| * 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 |
| rsqrt(float x) |
| { |
| #if !defined(SUBNORMALS_SUPPORTED) |
| int i = as_int(x); |
| int ai = i & 0x7fffffff; |
| int d = ai > 0 & ai < 0x00800000; |
| // scale subnormal by 2^26 without multiplying to avoid input flush |
| float s = as_float(i | 0x0d800000) - 0x1.0p-100F; |
| x = d ? s : x; |
| x = native_rsqrt(x); |
| x *= d ? 0x1.0p+13F : 1.0F; |
| return x; |
| #else //SUBNORMALS_SUPPORTED |
| return native_rsqrt(x); |
| #endif |
| |
| |
| } |
