| // checking if floating point math traps |
| |
| /*************************************************************************** |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed |
| * with this work for additional information regarding copyright |
| * ownership. The ASF licenses this file to you under the Apache |
| * License, Version 2.0 (the License); you may not use this file |
| * except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| * implied. See the License for the specific language governing |
| * permissions and limitations under the License. |
| * |
| * Copyright 1999-2007 Rogue Wave Software, Inc. |
| * |
| **************************************************************************/ |
| |
| /* IEEE 754 (IEC 559 supeseded by IEC 60559) specifies that |
| * the following operations return NaN unless they trap: |
| * |
| * 1. sqrt (n); n < 0 |
| * 2. rem (x, 0.0), rem (inf, x) |
| * 3. 0 * inf |
| * 4. 0.0 / 0.0, inf / inf |
| * 5. inf - inf (when both inf have the same sign) |
| * |
| * Traps are defined as kind of an exception, typically |
| * causing the delivery of SIGFPE (e.g., with Compaq C++ |
| * on Tru64 UNIX, except when using the -ieee flag which |
| * disables traps as required by C). |
| */ |
| |
| #include "nodbg.h" |
| |
| double dbl_get_zero (); |
| double dbl_get_one (); |
| |
| int main (int argc, char*[]) |
| { |
| nodbg (); |
| |
| double dbl_inf; |
| double dbl_nan; |
| |
| double dbl_zero = dbl_get_zero (); |
| double dbl_one = dbl_get_one (); |
| |
| // compute infinity (division by zero may trap) |
| dbl_inf = dbl_one / dbl_zero; |
| |
| // computation involving infinities that might trap |
| dbl_nan = dbl_zero * dbl_inf; // #3 |
| dbl_nan = dbl_zero / dbl_zero; // #4a |
| dbl_nan = dbl_inf / dbl_inf; // #4b |
| dbl_nan = dbl_inf - dbl_inf; // #5 |
| |
| if (argc > 2) |
| return dbl_nan; |
| |
| if (argc > 1) |
| return dbl_inf; |
| |
| // NEGATIVE test: successful exit status indicates a failure |
| return 0; |
| } |
| |
| // foil optimizers |
| double dbl_get_zero () |
| { |
| static double value = 0.0; |
| |
| return value; |
| } |
| |
| |
| double dbl_get_one () |
| { |
| static double value = 1.0; |
| |
| return value; |
| } |