1 /* 2 * Copyright (c) 2003, 2007-14 Matteo Frigo 3 * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 * 19 */ 20 21 22 #include "kernel/ifftw.h" 23 24 #if HAVE_NEON 25 26 /* check for an environment where signals are known to work */ 27 #if defined(unix) || defined(linux) 28 # include <signal.h> 29 # include <setjmp.h> 30 31 static jmp_buf jb; 32 sighandler(int x)33 static void sighandler(int x) 34 { 35 UNUSED(x); 36 longjmp(jb, 1); 37 } 38 really_have_neon(void)39 static int really_have_neon(void) 40 { 41 void (*oldsig)(int); 42 oldsig = signal(SIGILL, sighandler); 43 if (setjmp(jb)) { 44 signal(SIGILL, oldsig); 45 return 0; 46 } else { 47 /* paranoia: encode the instruction in binary because the 48 assembler may not recognize it without -mfpu=neon */ 49 /*asm volatile ("vand q0, q0, q0");*/ 50 asm volatile (".long 0xf2000150"); 51 signal(SIGILL, oldsig); 52 return 1; 53 } 54 } 55 X(have_simd_neon)56 int X(have_simd_neon)(void) 57 { 58 static int init = 0, res; 59 60 if (!init) { 61 res = really_have_neon(); 62 init = 1; 63 } 64 return res; 65 } 66 67 68 #else 69 /* don't know how to autodetect NEON; assume it is present */ X(have_simd_neon)70 int X(have_simd_neon)(void) 71 { 72 return 1; 73 } 74 #endif 75 76 #endif 77