Initial release of Optimized Routines

1 files changed, 100 insertions, 0 deletions

diff --git a/math/s_sin.c b/math/s_sin.c
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+/*
+ *  s_sin.c - double precision sine function
+ *
+ *  Copyright (C) 1998-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of the Optimized Routines project
+ */
+
+/* @(#)s_sin.c 1.3 95/01/18 */
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunSoft, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+/* sin(x)
+ * Return sine function of x.
+ *
+ * kernel function:
+ *      __kernel_sin            ... sine function on [-pi/4,pi/4]
+ *      __kernel_cos            ... cose function on [-pi/4,pi/4]
+ *      __ieee754_rem_pio2      ... argument reduction routine
+ *
+ * Method.
+ *      Let S,C and T denote the sin, cos and tan respectively on
+ *      [-PI/4, +PI/4]. Reduce the argument x to y1+y2 = x-k*pi/2
+ *      in [-pi/4 , +pi/4], and let n = k mod 4.
+ *      We have
+ *
+ *          n        sin(x)      cos(x)        tan(x)
+ *     ----------------------------------------------------------
+ *          0          S           C             T
+ *          1          C          -S            -1/T
+ *          2         -S          -C             T
+ *          3         -C           S            -1/T
+ *     ----------------------------------------------------------
+ *
+ * Special cases:
+ *      Let trig be any of sin, cos, or tan.
+ *      trig(+-INF)  is NaN, with signals;
+ *      trig(NaN)    is that NaN;
+ *
+ * Accuracy:
+ *      TRIG(x) returns trig(x) nearly rounded
+ */
+
+
+#include "arm_math.h"
+#include "math_private.h"
+#include <errno.h>
+
+__attribute__((const)) double
+ARM__sin(double x)
+{
+  double y[2],z=0.0;
+  int n, ix;
+
+  /* High word of x. */
+  ix = __HI(x);
+
+  /* |x| ~< pi/4 */
+  ix &= 0x7fffffff;
+  if(ix <= 0x3fe921fb) return ARM__kernel_sin(x,z,0);
+
+  /* sin(Inf) */
+  else if (ix==0x7ff00000 && !__LO(x))
+    return MATHERR_SIN_INF(x);
+  /* sin(NaN) */
+  else if (ix>=0x7ff00000)
+    return DOUBLE_INFNAN(x);
+
+  /* argument reduction needed */
+  else {
+    n = ARM__ieee754_rem_pio2(x,y);
+    switch(n&3) {
+    case 0:  return  ARM__kernel_sin(y[0],y[1],1);
+    case 1:  return  ARM__kernel_cos(y[0],y[1]);
+    case 2:  return -ARM__kernel_sin(y[0],y[1],1);
+    default: return -ARM__kernel_cos(y[0],y[1]);
+    }
+  }
+}