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+/* This file is part of Om. Copyright (C) 2006 Dave Robillard.
+ *
+ * Om 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.
+ *
+ * Om 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 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.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef UTIL_H
+#define UTIL_H
+
+#include <iostream>
+#include <cstdlib>
+
+#include <fenv.h>
+#ifdef __SSE__
+#include <xmmintrin.h>
+#endif
+
+using std::cerr; using std::endl;
+
+namespace Om {
+
+/** Set flags to disable denormal processing.
+ */
+inline void
+set_denormal_flags()
+{
+#ifdef __SSE__
+ unsigned long a, b, c, d;
+
+ asm("cpuid": "=a" (a), "=b" (b), "=c" (c), "=d" (d) : "a" (1));
+ if (d & 1<<25) { /* It has SSE support */
+ _MM_SET_FLUSH_ZERO_MODE(_MM_FLUSH_ZERO_ON);
+
+ asm("cpuid": "=a" (a), "=b" (b), "=c" (c), "=d" (d) : "a" (0));
+ if (b == 0x756e6547) { /* It's an Intel */
+ int stepping, model, family, extfamily;
+
+ family = (a >> 8) & 0xf;
+ extfamily = (a >> 20) & 0xff;
+ model = (a >> 4) & 0xf;
+ stepping = a & 0xf;
+ if (family == 15 && extfamily == 0 && model == 0 && stepping < 7) {
+ return;
+ }
+ }
+ asm("cpuid": "=a" (a), "=b" (b), "=c" (c), "=d" (d) : "a" (1));
+ if (d & 1<<26) { /* bit 26, SSE2 support */
+ _mm_setcsr(_mm_getcsr() | 0x40);
+ //cerr << "Set SSE denormal fix flag." << endl;
+ }
+ } else {
+ cerr << "This code has been built with SSE support, but your processor does"
+ << " not support the SSE instruction set." << endl << "Exiting." << endl;
+ exit(EXIT_FAILURE);
+ }
+#endif
+ // Set 387 control register via standard C99 interface
+ fesetround(FE_TOWARDZERO);
+}
+
+} // namespace Om
+
+#endif // UTIL_H