First omp

2026-06-23 15:07:55 +02:00
parent b842990cd4
commit 77d2dad320
18 changed files with 789 additions and 88 deletions
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+/**++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ *
+ *                                              PANIC
+ *                              Portable Algorithms and Numerics In C++
+ *
+ *                       Scientific computing from scratch, with feeling.
+ *
+ * Copyright (c) 2026 Michelle Bausager
+ *
+ * This file is part of PANIC.
+ *
+ * PANIC is free software licensed under the GNU General Public License v3.0 or later.
+ * You may redistribute and/or modify it under the terms of the GPL.
+ *
+ * PANIC 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 LICENSE file for the full license text.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *
+ *++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ *
+ * Project Name:      PANIC
+ * Module Name:       config
+ * File Name:         omp.hpp
+ * Revision:          0.1.0
+ * Date:              20-06-2026
+ * Author:            Michelle Bausager
+ *
+ * Description:
+ * Defines which types will be used in the rest of the libraries.
+ *
+ *++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++*/
+#pragma once
+
+//---------------------------------------------------------------------------------------------------------------------------
+// INCLUDE DESCRIPTION
+//---------------------------------------------------------------------------------------------------------------------------
+
+// None.
+
+//---------------------------------------------------------------------------------------------------------------------------
+// DEFINE DESCRIPTION
+//---------------------------------------------------------------------------------------------------------------------------
+
+//---------------------------------------------------------------------------------------------------------------------------
+// OPENMP CONFIGURATION DEFAULTS
+//---------------------------------------------------------------------------------------------------------------------------
+
+// If CMake did not define PANIC_USE_OPENMP, define it as 0.
+// This makes OpenMP disabled by default.
+//
+// CMake can override this with:
+//   PANIC_USE_OPENMP=1
+#ifndef PANIC_USE_OPENMP
+#define PANIC_USE_OPENMP 0
+#endif
+
+// If CMake did not define PANIC_OMP_NUM_THREADS, define it as 0.
+//
+// Meaning:
+//   0 = let OpenMP choose the default number of threads
+//   1 = use 1 thread
+//   2 = use 2 threads
+//   4 = use 4 threads
+//   etc.
+#ifndef PANIC_OMP_NUM_THREADS
+#define PANIC_OMP_NUM_THREADS 0
+#endif
+
+//---------------------------------------------------------------------------------------------------------------------------
+// OPENMP AVAILABILITY CHECK
+//---------------------------------------------------------------------------------------------------------------------------
+
+// PANIC_HAS_OPENMP becomes 1 only if:
+//
+//   1. PANIC_USE_OPENMP is enabled by CMake
+//   2. The compiler actually has OpenMP enabled
+//
+// _OPENMP is automatically defined by the compiler when OpenMP support is active.
+// For example, GCC defines _OPENMP when compiling with -fopenmp.
+#if PANIC_USE_OPENMP && defined(_OPENMP)
+#define PANIC_HAS_OPENMP 1
+#else
+#define PANIC_HAS_OPENMP 0
+#endif
+
+//---------------------------------------------------------------------------------------------------------------------------
+// STRINGIFY HELPERS
+//---------------------------------------------------------------------------------------------------------------------------
+
+// These macros turn macro values into text.
+//
+// Example:
+//   PANIC_OMP_NUM_THREADS = 4
+//
+// We need to turn that into:
+//
+//   "omp parallel for num_threads(4)"
+//
+// The two-step version is needed so that macros expand before becoming text.
+#define PANIC_STRINGIFY_DETAIL(x) #x
+#define PANIC_STRINGIFY(x) PANIC_STRINGIFY_DETAIL(x)
+
+//---------------------------------------------------------------------------------------------------------------------------
+// OPENMP PARALLEL FOR MACROS
+//---------------------------------------------------------------------------------------------------------------------------
+
+#if PANIC_HAS_OPENMP
+
+    #if PANIC_OMP_NUM_THREADS > 0
+
+        // Expands to:
+        //   #pragma omp parallel for num_threads(PANIC_OMP_NUM_THREADS)
+        #define PANIC_OMP_PARALLEL_FOR \
+            _Pragma(PANIC_STRINGIFY(omp parallel for num_threads(PANIC_OMP_NUM_THREADS)))
+
+        // Expands to:
+        //   #pragma omp parallel for if(condition) num_threads(PANIC_OMP_NUM_THREADS)
+        //
+        // The loop only runs in parallel if condition is true.
+        #define PANIC_OMP_PARALLEL_FOR_IF(condition) \
+            _Pragma(PANIC_STRINGIFY(omp parallel for if(condition) num_threads(PANIC_OMP_NUM_THREADS)))
+
+    #else
+
+        // Expands to:
+        //   #pragma omp parallel for
+        //
+        // OpenMP chooses the default number of threads.
+        #define PANIC_OMP_PARALLEL_FOR \
+            _Pragma("omp parallel for")
+
+        // Expands to:
+        //   #pragma omp parallel for if(condition)
+        //
+        // OpenMP chooses the default number of threads.
+        // The loop only runs in parallel if condition is true.
+        #define PANIC_OMP_PARALLEL_FOR_IF(condition) \
+            _Pragma(PANIC_STRINGIFY(omp parallel for if(condition)))
+
+    #endif
+
+#else
+
+    // If OpenMP is disabled or unavailable, these macros expand to nothing.
+    //
+    // So this:
+    //
+    //   PANIC_OMP_PARALLEL_FOR
+    //   for (...) {
+    //       ...
+    //   }
+    //
+    // becomes just:
+    //
+    //   for (...) {
+    //       ...
+    //   }
+    //
+    // That means the same code still works on microcontrollers and non-OpenMP builds.
+    #define PANIC_OMP_PARALLEL_FOR
+    #define PANIC_OMP_PARALLEL_FOR_IF(condition)
+
+#endif
+
+//---------------------------------------------------------------------------------------------------------------------------
+// TYPE DESCRIPTION
+//---------------------------------------------------------------------------------------------------------------------------
+
+// None.
+
+//---------------------------------------------------------------------------------------------------------------------------
+// VARIABLE DESCRIPTION
+//---------------------------------------------------------------------------------------------------------------------------
+
+// None.
+
+//---------------------------------------------------------------------------------------------------------------------------
+// FUNCTION PROTOTYPE
+//---------------------------------------------------------------------------------------------------------------------------
+
+// None.
+
+//PANIC_OMP_PARALLEL_FOR
+//for (panic::uint_t i = 0; i < length; ++i) {
+//    data[i] = value;
+//}