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-rw-r--r--src/math/s_cosf.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/src/math/s_cosf.c b/src/math/s_cosf.c
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+++ b/src/math/s_cosf.c
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+/* s_cosf.c -- float version of s_cos.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#include <math.h>
+#include "math_private.h"
+
+static const float one=1.0;
+
+float
+cosf(float x)
+{
+ float y[2],z=0.0;
+ int32_t n,ix;
+
+ GET_FLOAT_WORD(ix,x);
+
+ /* |x| ~< pi/4 */
+ ix &= 0x7fffffff;
+ if(ix <= 0x3f490fd8) return __kernel_cosf(x,z);
+
+ /* cos(Inf or NaN) is NaN */
+ else if (ix>=0x7f800000) return x-x;
+
+ /* argument reduction needed */
+ else {
+ n = __ieee754_rem_pio2f(x,y);
+ switch(n&3) {
+ case 0: return __kernel_cosf(y[0],y[1]);
+ case 1: return -__kernel_sinf(y[0],y[1],1);
+ case 2: return -__kernel_cosf(y[0],y[1]);
+ default:
+ return __kernel_sinf(y[0],y[1],1);
+ }
+ }
+}