comparison src/fftw-3.3.8/simd-support/avx2.c @ 82:d0c2a83c1364

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_AVX2
+
+#if defined(__x86_64__) || defined(_M_X64) || defined(_M_AMD64)
+#    include "amd64-cpuid.h"
+#else
+#    include "x86-cpuid.h"
+#endif
+
+int X(have_simd_avx2_128)(void)
+{
+    static int init = 0, res;
+    int max_stdfn, eax, ebx, ecx, edx;
+    
+    if (!init) {
+         cpuid_all(0,0,&eax,&ebx,&ecx,&edx);
+         max_stdfn = eax;
+         if (max_stdfn >= 0x1) {
+              /* have AVX and OSXSAVE? (implies XGETBV exists) */
+              cpuid_all(0x1, 0, &eax, &ebx, &ecx, &edx);
+              if ((ecx & 0x18000000) == 0x18000000) {              
+                   /* have AVX2? */
+                   cpuid_all(7,0,&eax,&ebx,&ecx,&edx);
+                   if (ebx & (1 << 5)) {
+                        /* have OS support for XMM, YMM? */
+                        res = ((xgetbv_eax(0) & 0x6) == 0x6);
+                   }
+              }
+        }
+        init = 1;
+    }
+    return res;
+}
+
+int X(have_simd_avx2)(void)
+{
+  /*
+   * For now 256-bit AVX2 support is identical to 128-bit.
+   * This might change in the future if AMD released AVX2-capable
+   * chips that work better with the 128-bit flavor, but since AMD
+   * might actually change it to implement 256-bit AVX2 efficiently
+   * by then we don't want to disable it before we know.
+   */
+  return X(have_simd_avx2_128)();
+}
+#endif