| /////////////////////////////////////////////////////////////////////////// |
| // |
| // Copyright (c) 2002, Industrial Light & Magic, a division of Lucas |
| // Digital Ltd. LLC |
| // |
| // 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 Industrial Light & Magic 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. |
| // |
| /////////////////////////////////////////////////////////////////////////// |
| |
| |
| |
| #include <iostream> |
| #include <iomanip> |
| |
| using namespace std; |
| |
| //----------------------------------------------------- |
| // Compute a lookup table for float-to-half conversion. |
| // |
| // When indexed with the combined sign and exponent of |
| // a float, the table either returns the combined sign |
| // and exponent of the corresponding half, or zero if |
| // the corresponding half may not be normalized (zero, |
| // denormalized, overflow). |
| //----------------------------------------------------- |
| |
| void |
| initELut (unsigned short eLut[]) |
| { |
| for (int i = 0; i < 0x100; i++) |
| { |
| int e = (i & 0x0ff) - (127 - 15); |
| |
| if (e <= 0 || e >= 30) |
| { |
| // |
| // Special case |
| // |
| |
| eLut[i] = 0; |
| eLut[i | 0x100] = 0; |
| } |
| else |
| { |
| // |
| // Common case - normalized half, no exponent overflow possible |
| // |
| |
| eLut[i] = (e << 10); |
| eLut[i | 0x100] = ((e << 10) | 0x8000); |
| } |
| } |
| } |
| |
| |
| //------------------------------------------------------------ |
| // Main - prints the sign-and-exponent conversion lookup table |
| //------------------------------------------------------------ |
| |
| int |
| main () |
| { |
| const int tableSize = 1 << 9; |
| unsigned short eLut[tableSize]; |
| initELut (eLut); |
| |
| cout << "//\n" |
| "// This is an automatically generated file.\n" |
| "// Do not edit.\n" |
| "//\n\n"; |
| |
| cout << "{\n "; |
| |
| for (int i = 0; i < tableSize; i++) |
| { |
| cout << setw (5) << eLut[i] << ", "; |
| |
| if (i % 8 == 7) |
| { |
| cout << "\n"; |
| |
| if (i < tableSize - 1) |
| cout << " "; |
| } |
| } |
| |
| cout << "};\n"; |
| return 0; |
| } |