Added macros to compute the minimum and maximum of integers

src/Makefile.am

@@ -45,7 +45,7 @@ AM_SOURCES = space.c runner.c queue.c task.c cell.c engine.c \
 
 # Include files for distribution, not installation.
 nobase_noinst_HEADERS = approx_math.h atomic.h cycle.h error.h inline.h kernel.h vector.h \
-		 runner_doiact.h runner_doiact_grav.h units.h intrinsics.h \
+		 runner_doiact.h runner_doiact_grav.h units.h intrinsics.h minmax.h \
 		 hydro.h hydro_io.h gravity.h \
 		 gravity/Default/gravity.h gravity/Default/runner_iact_grav.h \
 		 gravity/Default/gravity_part.h \

src/minmax.h

+/*******************************************************************************
+ * This file is part of SWIFT.
+ * Copyright (c) 2016   Matthieu Schaller (matthieu.schaller@durham.ac.uk).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+#ifndef SWIFT_MINMAX_H
+#define SWIFT_MINMAX_H
+
+/**
+ * @brief Minimum of two numbers
+ *
+ * This macro evaluates its arguments exactly once.
+ */
+#define min(a, b)           \
+  ({                        \
+    __typeof__(a) _a = (a); \
+    __typeof__(b) _b = (b); \
+    _a < _b ? _a : _b;      \
+  })
+
+/**
+ * @brief Maximum of two numbers
+ *
+ * This macro evaluates its arguments exactly once.
+ */
+#define max(a, b)           \
+  ({                        \
+    __typeof__(a) _a = (a); \
+    __typeof__(b) _b = (b); \
+    _a > _b ? _a : _b;      \
+  })
+
+#endif /* SWIFT_MINMAX_H */