comparison src/fftw-3.3.8/simd-support/neon.c @ 167:bd3cc4d1df30

Add FFTW 3.3.8 source, and a Linux build

+/*
+ * Copyright (c) 2003, 2007-14 Matteo Frigo
+ * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+
+#include "kernel/ifftw.h"
+
+#if HAVE_NEON
+
+/* check for an environment where signals are known to work */
+#if defined(unix) || defined(linux)
+  # include <signal.h>
+  # include <setjmp.h>
+
+  static jmp_buf jb;
+
+  static void sighandler(int x)
+  {
+       UNUSED(x);
+       longjmp(jb, 1);
+  }
+
+  static int really_have_neon(void)
+  {
+       void (*oldsig)(int);
+       oldsig = signal(SIGILL, sighandler);
+       if (setjmp(jb)) {
+	    signal(SIGILL, oldsig);
+	    return 0;
+       } else {
+	    /* paranoia: encode the instruction in binary because the
+	       assembler may not recognize it without -mfpu=neon */
+	    /*asm volatile ("vand q0, q0, q0");*/
+	    asm volatile (".long 0xf2000150");
+	    signal(SIGILL, oldsig);
+	    return 1;
+       }
+  }
+
+  int X(have_simd_neon)(void)
+  {
+       static int init = 0, res;
+
+       if (!init) {
+	    res = really_have_neon();
+	    init = 1;
+       }
+       return res;
+  }
+
+
+#else
+/* don't know how to autodetect NEON; assume it is present */
+  int X(have_simd_neon)(void)
+  {
+       return 1;
+  }
+#endif
+
+#endif